E-/tt - Loan from the wxorld Bankn Guangxi Environmental V* S Protection Project Statement on Environmental Impact Assessment of Chaoyangxi Comprehensive Treatment Project in Nanning City Guangxi Zhuang Autonomous Region Compiler: Chirncsc Research Academy of Environmental Scicnces Ccrtificatc Grade: A Ccrtificate Numbcr: NEPA Ap 0901 Compiililg Time: April. 1995 a 4 1 I'V II I 4. i ~~~~~~~~~~~~~~~~I'c' Contents Executive summary L. PREFACE ....................................................... 1I I. I PURPOSE OF ASSESSMENT . 1.2 BASIS FOR THE COMPILING OF EIA . 1.3 SCOPE AND STANDARD OF EIA .2 1.4 GOALS OF ENVIRONMENTAL .3 1.5 CONTENTS AND KEY OF ASSESSMENT ......................................................., 3 1.6 MAIN TECHNIQUES AND MEASURES ADOPTED [N THE ASSESSMENT. 3 1.7 BRIEF INTRODUCTION OF ASSESSMENT INSTITUTIONS AND PERSONNEL 5 2. GENERAL INTRODUCTION TO PROJECT CONSTRUCTED WITH LOANS. 6 2.1 BASIC SITUATION OF THE PROJECT .6 2.2 PRODUCTION TECHNOLOGY .1 7 2.3 MAJOR POLLUTION SOURCES AND THEIR DISCIiARGING OF POLLUTANTS .20 3. GENERAL SITUATION OF THE ENVIRONMENT OF THE AREA OF THE PROPOSED PROJECT .23 3.1 NATURAL [ENVIRONMENT .23 3.2 GENERAL. SIT1UATION OF ITS ECOLOGICAL ENVIRONMENT .26 3.3 SOCIAL. IENVIRONMEN .26 3.4 PEOPLE'S I.!FE QUALITY .28 3.5 ENVIRONMENTAL QUALIT,Y .29 4. PREDICTED ENVIRONMENTAL IMPACT AND CONTROLLING MEASURES .42 4.1 RECOGNITION OF ENVIRONMENTAL AFFECTING FACTORS AND SCREENING OF FACTORS TO BE ASSESSED ........ 42 4.2 ANALIYSIS ON TI IE CH IARACT1ERIS-I ICS OF ENVIRONMENTAL IMPACT ................................. 42 4.3 PREDICTION ON TI IE PROJIEC'S ENVIRONMENTAL EFFECT DURING ITS CONSTRUCTION ... 48 4.4 PREDICTION ON TIHE ENVIRONMENTAI. IMPACT DURING TiE II OPERATION OF TIIE P'ROJECT ............................................................................................ 68 4.5 RISK ANALYSIS .................................................................. 135 1 4.6 COUNTERMEASURES TO ELIMINATE OR EASE UP THE LNFAVORABLE IMPACT ................ 136 5. ALTERNATE PLANS ......................................................... 140 5.1 ALTERNATE PLAN FOR THE WASTE WATER INTERCEPTING SYSTEM ON THE CHAOYANG STREAM ................................... 141 5.2 ALTERNATE PLANS FOR THE TREATING OF THE WATER WAY OF THE CHAOYANG STREAM ................................ 147 6. ANALYSIS ON THE BENEFIT OF THE CHAOYANG STREAM COMPREHENSIVE TREATING PROJECT ................................... 149 6.1 ANALYSIS ON ITS SOCIAL BENEFIT ................................... 149 6.2 ANALYSIS ON THE ECONOMIC BENEFIT OF THE PROJECT ................................15......... 151 6.3 ANALYSIS ON ITS ENVIRONMENTAL BENEFIT ......................................... 158 7. PLAN FOR ENVIRONMENTAL ADMINISTRATION AND ENVIRONMENTAL MONITORING ......................................... 160 7.1 SETTING UP OF ENVIRONMENTAL PROTECTION BODIES ......................................... 160 7.2 MEASURES FOR ENVIRONMENTAL ADMINISTRATION ......................................... 161 7.3 ENVIRONMENTAL MONITORING PLAN ....................................: 162 8. P'UBLIC PARTICIPATION ...................................1 64 S. I A.I AND PURPOSI ..6.................................... 164 8.2 M ETI IODSOF INVESTIGATION ................................... 164 8.3 ScoPE OF INVESTIGATION ................................... 164 8.4 SUBJECT OF INVESTIGATION ................................... . 164 8.5 METI-IOD OF INVESTIGATION ................................... 165 8.6 ANALYSIS ON THIE RESUITS OF INVESTIGATION ................................... 165 9. CONCLUSION ............ .170 Attachment 2 Statement on Environmental Impact-Assessment of Chaoyangxi Comprehensive Treatment Project in Nanning City Compiler of the assessment: Chinese Research Academy of Environmental Sciences President: Chen Fu(Professor) Persons in charge of the item: Jin Xiangcan (director, professor) Cao Hongfa (director, professor) Main Participants and their qualification: Name Subject Division Qualification Specialth Jin Xiangcani Engineering analysis recognition of Professor Water environment environmuent factors Cao Hongla Management and monilonng plan Professor Enmironunental ecologe Bon2 Denitin2 Analysis on the environmiental impact Professor En virounmental Clhenstrit during construction Li Junqi Measures on the envirounmenital impact Senior professor Environmental Chemistry during construction Xu Nani il Alternative plants anid Nattire Senior engineer Water environein enivironment l:u Guo Water environmental impact assessme:nt Engineer Environmental hv-draulics .JI1 Daaniue Environmental cost-Beniefit analysis Engineer management Wan2 Yu Existing enviroiunental qutalitx Seiior en2iiieer Env-ironmziental monitonn2 flan l.ng Pliblic participationi and demolishing and Seiiior eingineer lnVironmnental plan reimioval work [I lan Xilig!t Measures on noise durinig coistnictnoni Senior engineer lEnvironimenial engineer Ciao l:tlmllia Investigation and assessment of existing Senior engineelr Environmental monitonng Environimental quality Kwinge Jieren Investigationi and assessmelint ol exisitilg Seniior enginieer Environmiental tionitonng E'nvironmnental quality Z;hou Yunxin Investigationi and assessmenit ot existing Senior cilgineer Evinironmnental nionitonn2 Environmental qtualitv l,glio iiu Investigation and assessmlent of exi sting Scnior engin.eer l nvironmental monittonng Envirolunental quality I htnig Chao Investigation and assessment of existing Senior enngineer Environmental mnonitoniioJ Enivironientai quality Nlionitorinig participation ClienJiabao Xie Ytt Xie I lonigbit l.tang .lttiuinig( femiale) Lang Zlitting(tniale) Z.atiag lhiulting L.it Yon-iguing Shii Niaiqimig I ltianig M;toc;ai .ain Jil'eieing Yuin Weilianto Xti Xaohta Zhanig Qtioguitl 1'eii WVeiutgli, imuang l)ong Wei L.iqutn ktu Yuuileti P'an Yiliing Fei Xuioqi 1.m iie Suill (itit luang llaibao Clen Situang /.iul )anitang Wei Cuitinim Wui Xtaovin L.an I uatllao f fuzing Sitlitia Xi Ytuqlimg Zhitt Wenjiutn Li WVeikang Li Fang I [itnilng Zilenilhenig a, I5 ~~~~~ir~~~~~~~J l s"ec;oec4n0e ~~~~~.~ \;. A4I E t R f }, ;tzn 4-~ ~ ~~k- 14- g 1io 9 ot g~~~~~~~~~~~~~~~~~~~~~T- llt INT, 9ifIATf t I so U EXECUTI E SUMMARY Nanning is the capital of Guangxi Zhuang Autonomous Region, serving as its political, economic, financial, cultural center, as well as the region's center of science, technology and information. It is also the hub of transportation, which links the sea with southwest China. The State Council decided in 1992 to open the city of Nanning and turn it into an international garden city facing Southeast Asia with unique ethnic and local characteristics. The city has a total area of 10 029km2, with a population of 1.07 million (1994), of which 0.76 million living in the urban area. The city govemment of Nanning is planning to renovate the Chaoyang Stream, better the city's waste water and rain collecting system and built waste water treatment plants with loans from the World Bank so as to bring the pollution into control, improve its water quality and the life quality inhabitants, as well as to make the city more adapted to further opening up. 1. Main content and investment of the proposed project See table I for the main content and investment of the Chaovang Stream treatment project is as follow table: Table I Main content and investment for the comprehensive environmental treatment project of the Chaoyang Stream in Nanning City No. Procic Mam Coniteit investment I *nic Chaovang Strcam Treatmlient Project id) Inginieerini of renovationl of the river Renovation of'thle nver course. 1 004( l0' vuanl course | zatr supplciemet_ _ (2) Interceptioni Svsteni of vwaste water d'IF0-d-2000inin, L=6Skni I__'__ _ _ _) X 2000f)-C 80oo 2400mi i_iii (3) pipeline of passing river 1= l kl;t (4) liangbei main sewer r 1S0 X 2400mm [.=1.2kmri (5) Waster wvater raising ptunp station 2 -:f Is (one) (6) waste water treating plant 2 > *10 mId subtotal 25046( 104 yuan) 2 Drainage system prolect in Nanning I ) Rain trunk i: -ani main trnks, d600-d200tu),im 1 2806( 104 yuan) L I tox I1000-C 2800 x 18 )00niui (2) Sewer pipeline 2' R1 0 0 r / . ~~~~~~~~~~~~LX i ji| 00* i :t r , ' il ,' ''-,' ' '' ,i. it r t. >t '" : sS"i''TiN S '-& :' " <>/& ;; J tig' 1|§Z} I nT N,~~~~~~~~T * ; /vsE ,X=-/ o- NzAS \ t : Q z / > b_~~~ ',- .1 *. _ , -zz m . I | << ~~~~~~' Q V / ___, /' I_X K,,',lt, r ,, I DRAINAGE SYSTEM PROJECT IN NANNING PLAN OF WATER SEWERS AND CONDUITS F - - -~~~~~~~~- - -- - - ,, r ) i I I N \A ' I la^in scilrftcFi . , |mAnji ~~~~~~~~~~~~~~~~~~~~~~~~~~~Road to I_,d\- , - t 01 -- 5\ 1 . . ;0)rnmain sewer -* - r^swOrCScn A~~~~~~~~~~~~~~~~~~~~~~~~ch Ro Y1'a ,~ ~ ~ ~ ~ ~ ~~~~~~~~mi sete h!i svAe of th S'Eond ' tnt / \ 11 ql A 1 l \S, li ~~~~~- if d lo lh4x Ro4Tnshnl ;vayo ,1~~~~~~~~~~~~~~- .. * \ 1 r thlreR°a;Ab pnnnBitr ""' ! I 2<, n899der 't-s c z , t / |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~A -- ' - - !l I > - ij j j ,~~~~~~~~~ - \ s, ~~~~~~~~~~~ ~~~~ Ij ngon -41asiewate f v. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I Fig. 4-4-I Distribution of BOD; Concentration under Loxv Water Condition %ith 1995 Year Load Fig. 4-4-2 Distribution of BOD5 Concentration under Hieh Water Condition with 1995 Year Load Fig. 4-4-3 Distribution of BOD, Concentration under Norrtal Water Level Condition with 1995 Year Load Fig. 4-4-4 Distribution of BOD, Concentration under Lo%% Water Condition with 2000 Year Load after Level I Treatment at Shuitangjiangkou Fig. 4-4-5 Distribution of BOD5 Concentration under Lovs Water Condition wvith 2000 Year Load after Level I Treatment at Zhupaichong Fig. 4-4-6 Distribution of ROD, Concentration under Low Water Condition wvith 2000 Year Load after Level 2 T'reatment at Zhupaichong Fig. 4-4-7 Distribution of BODI Concentration under Low Water Condition with 2015 Year Load after Level I Treatment at Shuitangjiangkou Fig. 4-4-8 Distribution of BOD, Concentration under Low% Water Condition with 2015 Year Load after Level 2 Treatment at Shuitangjiangkou Fig. 4-4-9 Distribution of BOD, Concentration under lligh Water Conditioni with 2015 Year Load ai'ter Level I T'reatment at Shuitangjiangkou Fig. 4-4-10 Distribution of BODI Concentration under Normal Water Lexel Condition with 015 Year Load after Level I treatment at Shuitangjiangkou lFig. 4-4-11 Distribution of BOD, Concentration under Low Water Condition %% ith 2015 Year l.oad al'ter Level I 1'reatmient when the Beise Reservoir Is Functioning Fig. 4-4-12 Distribution of 130D, Concentration under Lo%% Wk'ater Condition with 2015 Year Load without any 'I'reatment I:ig. 4-5-1 Distribution of D() Concentration under li.o% Water Condition %\ inh 1995 Year load Fitg 4-5-2 I)istribution of DO Conceiitratikn unider I ligh Water Conditon \ ith 1995 Year Load Fig. 4-5-3 I)istribution of DO Coiteintratitn unider Normial Wkater level Coonditioni \%ith 1995 Year Load Fig.4-5-4 Distribution of DO Coitcentration under Low Water Condition %k ith 2000 Year Load at Shulitan&gjianigkou at'ter Le,el I T'reatnment Fig. 4-5-5 Distribution of DO Concentration under Lo\% W 'ater Condition %% ith 2000 Year Load at Zhupaichong after Level I Treatment Fiet. 4-5-6 Distributiott of Do Concentration Linder Low Water Condition %s ith 2000 Year Load at Zlitipaichonig alter Level 2 Treatment iFig. 4-5-7 Distribution of 1)0 Ctoncentration under Lo% k.;ter Condition with 2015 Year Load at Shuitang.iiangkou af'ter Level I 'reatinemt PFtg. 4-5-8 D)istribution of D)O Coticentration tinder L.ow ' Water Condition w% ith 2015 Year l.oad at Shuitangjiangkou al'ter Level 2 Ireatment Fig. J4-5-9 Distribution of DO Concentration under I ligh Water Condition wvith 2015 Year Load at Shuitagjianigkou after Lecei I 1'rcatmcnt l'ig. 4-5-10 Distribution of DO Concentration under Normal Water Le% el Condition with 2015 Year Load at Shuitagjiangkou after Level I 1'reatment Fig 4-5-1 I Distribution of DO Concentration under Normal Water Level Condition with 2015 Year Load at Shuitagpianekou after Level I Treatment Fig. 4-5-12 Distribution of DO Concentration under Low Water Condition with 215 Year Load w ithout an% Treatment Fig. 4-6-1 Distribution of COD,N, Concentration under Low Water Condition with 1995 Year Load Fig. 4-6-2 Distribution of CODM, Concentration under Low Water Condition with 1995 Year Load Fig 4-6-3 Distribution of COD,", Conccntration under Low Watcr Condition with 2015 Year Load at Shuitangjiangkou after level 2 treatment Fig. 4-6-4 Distribution of COD,,, Concentration under Low Water Condition with 2015 Year Load at Shuitangjiangkou after level I Treatment when the Beise Reservoir Is Functioning 1. Preface 1.1 Purpose of assessment Nanning is the capital of Guangxi Zhuang Autonomous Region, serving as its political. economic. financial, cultural centcr. as well as the region's center of sciencc. technology- and infornation. It is also the hub of transportation. wvhich links the sea with southwest China T'he State Council decided in 1992 to open the city of Nanning and turn it into an inteniational garden city facing Southeast Asia with unique ethnic and local charactenrstics. The city has a total area of 10 029km2, with a population of 1.07 million (1994). of which 0.76 million living in the urban area. The Yongjiang River is a major river flowing through the city of Nanning from the east to the west. With abundant water, the river is the main source of drinking water and industnal wvater of the city. The Chaoyang Strcam. a tributary of the Yongjiang River. has been receiving daily sewage from a quarter of 0.25 million of people and waste wvatcr from over a hundred enterprises sincc the 70's, functioning as the main Nvaste water discharge ditch in the central part of the city. Its w%ater is noxv heavill polluted and seriously silting up. bringing harrnful effect noE onlv to the health and dailv life of inhabitants along the river but also to the appearance and h! gienc of the city. Tnc city doesn't have an integrated discharge water sy stem and lacks flood controlling capacity. -Th citv govemment of Nanning is planning to renovatc the Chaovang Stream. bencr the city's wastc wvatcr and rain collecting system and built waste water treatment plants with loans from the World Banik so as to bring the pollutioni into control. improve its wvater quality and the lifc quality inhabitants, as well as to make the city more adapted to further opening up. Tlhcre arc tmo proposed projccts: (I) To renovatc tihc Chaovang Strcami (2) To improve thc drainage system in Nanning City. Thc above two projects arc known as the 'comprchcisi'e treatmcnt of the Chao\ang Streanm The purpose of compiling thils asscssmcnt is to predict and analyze the environmental impact and bencfit (both positive and neiativc) during the construction and operation of thc project ti light of thic cnvironmental situation and gcneral dcvelopmcnt plan of Namintig Cit%. tlhus providing a scientific basis for thc policy making of the project 1.2 Basis for the comilpiling of EIA 1.2 I Documitient Guolitiani (86) 003 b thce National Environieintital Protectionl Agenc\ -*Procedurcs of Environment Admiinistration of Constnictioui Programs'': 1.2.2 Doculicnit HLuan1jian (1993) 324 b! the National of Environmental Protection Agenc\_ State Planning Commission, Ministrv of Finance. and Pcople's Banlk of Chiina "Notice on Strengtthening Environmental Administration ovcr Construction Programs %\lth Loans froni Intcrnational Financial Organizations": I 1.2.3 Document Jitouzi (1994) 441 by State Planning Commission: "Written Reply to Proposals of Guangxi Environmental Protection Prograrns Using Loans from the World Bank"; 1.2.4 Document Guizhengbanhan (1995) 59 b thc City Government of Nanning: --Reply to the Plan of the Chaoyang Stream Control Projcct": 1.2.5 Beijing Municipal Works Designing Instituic (Oct. 1996): "Report on the Feasibility of the Comprehensive Control of the Chaovang Stream in Nanning, Guangxi Zhuang Autonomous Region"" 1.2.6. -Technical Guidebook of Environmental Impact" as listed in "Professional Standard HJ/T2.1-2.3-93 for Environmental Protection Trade' bv the National Environmental Protection Agenc-' 1.2.7. Official wvrinen reply to --Outline of EIA of the project by NEPA.". 1.3 Scope and Standard of EIA 1. 3.1 .Srandard of E:IA Tnc standard set in-the replay to the standard of EIA by Nanning Citv Environmental Protection Bureau is used. which includes the following: (I) GB3838-88 grade V of -Standard of Surfacc Water Environmental Quality'' and GB12941-91 gradc C of "Water Quahtv Standard for Sccncr and Recreation Area" for Chaoyang Strcam Water Quality. GB3838-88 grade Il of "Standard of Surface Watcr Environmental Quality" for Yongliang River water quality. Surfacc water of Erkcng and Zhupaicihone Stream shall not be below thcir present watcr qualhtx (2) GB4280-84 acidic soil standard of "Standard of Farmiland Pollutants Control Using Sludg'e for sediment of Chaoyang Strcam and sludge of sewage treatment factorv. (3) GB8978-88 Gradc 11 of "Integrated \Vastc water Dischargc Standard" for vatcr discharged by the Jiangnan scwagc trcating plant (4) GB2523-90 "Limitiig Value of Building Construction Border Noise" anid GB3096-93 Gradc II of "Standard of Urban Environmcntal Noisc" for environmental noise. (5) GB3095-82 Grade 11 of "Standard of Atmosphere Environmental Quality" for atmospilere cnvironment. (6) GB5749-85 "Standard of Drinkinig WX'atcr" for ground water. I 3 2 .Scope of assessUiWenf I) Assessmcnt scope of water environment Considerinig the flowing direction of the %%astc water from the planned construction project and surfacc runoff. Chaoyang Strcam. Erkens Strcam. Zlupaichcng Stream, Nanhu Lake. and Slitltangiang Stream are sct as the scope of the assessment of the YongJiang tributary. Ikm upstream of the discharge opening of Jiangnan waste wvater treating plant to 4 km downstream of Shuitangjiang Stream as the assessment scope of Yongjiang River Howevcr, the scope for water qualitv assessment covers a somewhat larger scope. (2) Asscssment scope of solid waste According to the characteristics of the planned project, sedimcnt and sludge dredged, and castawvay soil and garbage of the construction shall be assessed. and the scopc includes both sides of transportation routes and permancnt and temporary material piling grounds.. (3)Assessing scope of noisc and raised dust Construction area and both sides of transportation routcs 1.4 Goals of environmental protection Tlhere arc no important cultural heritage cites or statc protectcd rare species of widelife or and plants in the assessed area. Goals of the environmental protection of this projcct are inhabitants, drinking water sources and citv landscape. 1.5 Contents and key of assessment 1.5. 1 Contents of assessnweni Impact of construction noise Impact on Raised dust during construction Impact on city traffic and landscape during construction Impact of thc removal of buLidings and resettlement of inhabitants on the environment Impact of sedimeint and sludge drcdged on the environmcnt Impact of discharged water from Jiangnait waste water treating plant on thc water qualitv of thle Yongjiang River w\atcr quality dtirinig the opcration of the plaiiined project Impact of pollutants from non-poinlt sources on receiving water bodics during operation 1.5.2 Key' ol assessnit't,t Impact of thc project on people's life and city function during construction Anaklsis of thc impact of dredged sludge during the trcating of the river beds Prediction of the impact of dischargcd water from Jiangnan waste water trcating plant on thc Yongjiaig River wvater qualit! durinig operation Prediction of the impact of polilutalts from the citys non-poinit sources oni the water quality of thc Nanilu Lakec during operationi 1.6 Maini teciihniqtues and measures adopted in the assessmenit 6. / IProcechire of,sse('ssment See Fig 1-2 for the procedurc of thc assessment.: 3 L Certificate of Entrustment of Projloct Filed survey and infomiation collect on the project's eavironment I - Environmental questions and fancories on the project to be taken| Recognition of environmental affeting factors Outitnt of Environmental Impaat Assessment Sutbnit to NEPA yes * I~~~~~~~~~~~~~~~~~~ M Xonitoring and ascs i oxitin eniomntlqalsitys Oofdeprojtect Noise I Atmospheric Water Solid waste EUological Natural and social Experts optmions enwotnni Environment. Environment namtr Environment Environenit Detail list - 4L: Prediction and assessment on the project's environmental effect 1 Statement on environmental impact assessment of subprojects I Statentit o,i environmental uipact assessintu on the projec-t of compreihinlmseve treatniwnt o l thc l1ijianig Ri%er in Guilin __- _ NoSubinat to NEPA To do basis prorposd tnvironmnenital tecudolopg and nieastires adopted in the projcet. Fig. 1-2 Procedure of assessment / 6 2 Al1aor techniqucs itscd in the asscssment In light of thc charactcristics of thc projcct and with advisc from cxpcrts. the matrix nmethiod is uscd to screcn major cnvironnicntal factors to be asscsscd: thc singic-factor method is adoptcd in asscssmcnt of cxistinlg cnvironnicntal condition; the analogical mcthiod combincd with model forccast arc adoptcd in thic prediction of thc environmental impact: and sampling stirncy is adoptcd for public participation. Effcctivc environmcntal cnginccring mcasures arc proposcd for major cnvirontiiental probliems which mighit appear during constriction and operationi of the project. 41 1.7 Brief introduction of assessment institutions and personnel 1. 7. 1 Brief introduction of assessment institluinont A comprehensive environmental scientific research institutc directly under the National Envirotuncntal Protection Agencv (NEPA). the Chinese Research Academv of Environmental Sciences is of a large scale, wvith multitude disciphinanans. advanced equipments. rich technical capacity, and wvide scope of research. It has now a total staff of 580, of whom arc 2 academician of the Chinese Engineering Academy. 30 professors, 106 associate professors, and 258 assistant researchers and engineers. It is enrusted with the responsibilitv for the establishment of state environmental standards and technical examinations. and the responsibilit of technical monitoring and administration of environmental impact assessment of construction programs by the NEPA. T'he academy has so far compiled over 200 environmental impact assessments--ranking number one in the country-- involving heat and electricity supply, air port, sea port . railwav and highlwav construction. and the supply of natural gas . petroleum, chemicals, iron and steel. as %%ell as w-ater conservatory. agriculture. animal husbandry, regional development. tourism. electronics. mining. and municipal engineering. 1. 7.2 Cooperating institutions Nanning Research Institute of Environmental Sciences Nanning Environmental Monitoring Station Guangxi Research Institute of Environmental Sciences Jinling University 1. 7. S Niee th lv1ecaf of this r)eport flbr the list of pi r /wk r.Iel tan/ g 1)art ini the I-:IA apici their qualification. 2. General Introduction to the Project Constructed with Loans 2.1 Basic situation of the project 2. 1.1 Name of the project: Comprehensive Environmental Treatment of the Chaovang Stream in Nanning City. 2.1.2 Nature of the project and category ofassessnient The purpose of the project of the comprehensive environmental treatment of the Chaoyang Stream is to treat thc river's dark and smelting river, to intercept the industrial waste water and sewage of the area along Chaovang Stream. and build a new Jiangnan waste water treating plant. The water discharging pipe netvork is to renovatc sewage and rain collecting system of Nanning City so as to collect industrial waste water from major pollution sources in Tingzichong. Jiangnan to be brought to the wvaste water treating plant for treatmnent. Completion of this project will improvc enviromtental qualitv and drainage system of Nanning City by solving the problem of water discharging of the city. thus beneficial to improving thc water qualitv of the Yongjiang River. This project is of long-term positive environmental effect. But it as the project is to be carried out in dowtntow%n arcas of the city wvith a fairln long duration, the largc amount of carth to be back filled and cast away. temporarily piling up of construction materials. and largc amounts of river sedimcnts to bc treated will causc somc negative environmental impact. The assessment of project is determined to be of A-B category. 2. /. 3 (CiOTrlp)hic locattion oft'iie project 1. The Chao-ann Stream Trcatment proicct Thc Chaovang Stream is locatcd in north of Nanning City. flo% ingz from the north to the south througil the urbani part of the city into the Yongiang Rivr. nh stream is 14.26km long. and the scction to bc trcatcd is 8.9km lona, from Nanning Heavy Machine Building Factory to Dakcngkou. with a catclnicnt arca is 17 i kni. The arca to bc served by the project covers iS.5km2. Sce Fig. 2-1 in the appendix for the layout of the river treating project, the wvaste water coliccting svstcni and the location of the %\aste water trcating plant. 2. Drainae svstemn protect in the urban areas of Nanning CitV The drainage s!stcmn project is locatcd in the urban arcas of Nanning City. involving Xinchcng D.istract. Xinigning Distract. Chengbel Distract, Yongjiang District and Jiangnan District (Fig 2-2 to Fig 2-4) 2 1.4 Scale and incaln confefnt nf thc propj;owed project I Thc Chaovann Stream Trcatment nroiect Thc content and scalc of the Chaovanig Stnram treatment project is as follo\vs: (1). Engineering of renovation of the river course River to be treated is from Nanning Heavy Machine Building Factory to Dakengkou. 8.4 km long. is 56.1% of all River length. The catchment of the part is 17.5 km2. 7 1.8% of Chaoyang Stream catchment. A. Engineering of renovation of the nrver course (downrstream) a. Location: from Youai bridge to Dakengkou: b: Scope: section: 1.7x3.0m. long: 3015m. B. Engineering of renovation of the rivcr course (midstream) a. Location: from Heavv Machine Budding Factory to Youai Bridge. b: Scope: from Heavy Machine Budding Factory to No. 28 School Youai bridge: 35.0x3.4mm, L=2133m; from No.28 School to Mingxiu Bridge: _5.6x3.4nm. L=880m, from Mingxiu Bridge to Nanmian Bnrdge: 76.0x3.4nimrn L=1325m: from Nanmian Bridge to Youai Bridge 06.2x3.4mm L=lOOOm: c. Benefit: c. Benefit: The catchment of the treated part is 17.5 km2 is 72% all catchment area. Calculated collecting waste water is 196.000m3/d, including industrial waste water 54000 m3/d. daily sewage is 142000m ;/d. Flood detention are 541 900 m;Jd. designed water level of Yongjiang River (67-72.17m), and have 54ha of surface area of landscape water and volume of water 107400m3. (2). Interception system of wvaster water a. Location. Anji street. Xiouan street. Railway east No. I and No.2 street; b: Scope: left side of Chaoyang Stream d I 550-2350, right side d 1950-2250. L=2700; c. Benefit The project shall intercept the existing maste water of the Chaoyang Stream. the Erkeng Stream. Anji strect. Xiouan Street and the left and right sides of railway and sent into the Dakengkou of Chaovanig Stream downstream. total waste water value is 840.000 m3/d, including the Chaoyang Stream area 350.000m;/d. Erkeng Stream area 220.000 m3/d, Xixiangtang arca 270.000111'/d (3). Waste water raising pump station a Location: A waste wvater raising puimp station shall be built at the joining point of the left and right waste wvater trunlk canals; b: Scope: first phase pump water value is 2.7mi/s. second phase is 6.5 m'/s. lift: 7mn: c. Benefit: The pump shiall pump waste water of collecting from the interception system of waste water into Jiangbei main sewver. (4). Pipeline of passing river a. Location: pumilp statioIl: b Scope: 3x d 1600nnmm: c. Benefit: Thc pipcline shall direct waste water of collecting from the interceptioni sv sten of waste water into Jiangbci main sewer. Jiangbei main sc\wer a Location: along Yongjiang dam and road. b: Scopc: L=4.2km. 1(3800x2400mm c. Benefit: Thc sewcer shall transport waste water into wvaste vater treating plant (6). Waste wzater treating plant a. Location: near Zhainitan, Jiangnan, the west of Yongjiang River; b: Scope: area be 73ha. 26m3/d, c. Benefit: to treat all collecting waste .%ztcr. 2. Drainag-c system project in Nannint A. Sexver and conduit (I) Zhiwulu rain trunk a. Location: Zhiwvu street b. Scope: d 1800-d2000mrn, L= 121 1 c. Content: reinforced concrete pipe d Benefit: The catchment of the treated part is 3Sha and into the Yongjiang River (2) Beihubeilu rain trunk a. Location: Beihubei street b. Scope: d600-OOmm, 0 1400xlO0002!2800x 1800mm, L=547 1m c. Content: reinforced concrete pipc d Benefit: The eatehment of the treated part is 270ha and into Chaovang Strean. (3) Lingxiulu-Mingxiuxilu rain Trunk a. Location: Lingxilu and Mingxiuxi street b. Scopc: d 1200-d 1400mm, L=4300,0 1400x.x 1400-r2800x2200num c. Content: reinforced concrete pipe d. Bcnefit: The catchrnent of the treated part is 186ha and into Chaoyang Stream. (4) Tangshanglu rain Trunk a location Tangshang street b. Scope: - 1400x1400- I 1600xl400nim. L=S2 00rn c Conitent reinforced concrctc pipe d. Benefit: lihe catclment of thc treated part is 120ha and into Chaovang Stream. (5) Hcngyangxilu rain trunk a. Location: Hengyangxi strect b. Scope: dl200-dl4OO. L=3200.5l60Oxl4O-.-.1 800xlXOOmmm c. Content. reinforced concrcte pipc d. Benefit: Thc catclimcnt of the treated part is 1)l6ha and into Chaoyang stream. (6) Hcngyangdonglu rain trunk a. Location Hengyangdong strcet b. Scope: -:1400x 400- -2200x2000inn. L=S'200m c. Content: reinforced concrctc pipc d. Benefit: The catchnciit of tihc trcated part is I S Ilia and into Chaoyang Strcam. (7) Hengyangxilu-Xiviangtanglu rain trunk a Location: Hieiigyanigxi and Xi%'iangtang street b Scope: I6t(xl140(-:lXOlOxlO(8nmm. L="20() c Content: reinforced concretc pipc I: d. Benefit: The catchmnent of the treated part is 64ha and Erkeng Stream. () Mingxiuxilu-Xingyanglu rain trunk a. Location Mingxiuxi and Xingxang street b. Scope: d8OO-dL000mm, 71l800x2200nim. L=1330m c. Content: reinforced concrete pipe d. Bencfit: The catchmncnt of the treated part is 46ha and into Erkeng Stream. (9) Mingzhudadao trcatment (10) Qixinglu-Jiaoyudadao rain trunk- a. Location: Qixing and Jiaovudadao street b. Scope: d1200-14400mm, L=3450m. - 1600xl400-C28OOxl800mm c. Content: reinforced concrete pipe d Bencfit: Thc catchment of the treated part is 16Sha and into Zhupaichong Stream. (I 1) Taovuanlu rain trunkl a. Location: Toving street b Scopc: d1400-1200mm. L=24 0m. '1 1600xl600-'_262060x1600rrimr c Conteint: rcinforced concrete pipe d. Benefit: Thc catchment of the treatcd part is 108ha and into Zhupaichong Strcam. (1 2) Mingzhulu-Guctienglu rain trunk a. Location: Mingzhu and Guchicng Street b. Scope: 01400xl600-3i2000xl600mmn. L=1 10(m c. Contcnt:rcinforccd concrcte pipe d Benefit: The catchliient of the treated part is 72hia and into Zlhupaichong Strcam. I U) Jiangnailti-Fujiarnlu rain tni;k a Location: Jiangnan and Fujian street b Scope: dI00O-12000mm. L=546ini.12:0()0x20()0- 2400x24001lnm c Content: reinforced concrcle pipe d Benefit: The catcinicint of the treatcd part is I (Xha and into Zhupaichong Streamn. B Sewer pipeline I ) Tinighonig sc\wcr pipcline a Location: Tingjiatn street b Scope: dfOO-700mim. L= I O0Oni. c Content: reinforced coiicretc pipe d Bencfit: The catcinicit of thc trcatcd part is i i hia and into Jiangbei sewcr pipelinc. 2) Baishadadao sec%er pipclilne a Location: Nanzihan and Baisha street b. Scope: d60(-900ni(m. L= .1 5Ol c. Conitenit: reinforced conicrcee pipe d Be3ncfit: Thie catchmciit of thc treated part is 369hia and into Jliangbci sewer pipelieic. C' lodification of drainage s%steim of oil urban I) IHiuaxilu drainage s! sten 13. a. Location: right bank of Chaovang Stream b. Scope: d 1000- 1800mm, L=990m c. Content: reinforced concrete pipe d. Benefit: nhc catchment of the treated part is 120ha and into Chaoyang Stream. (2) Huaqanglu drainage system a. Location: right bank of Chaovang Stream b. Scope: d1200-l600mmn,L=61Om c. Content: reinforced concretc pipe d. Benefit: The catchment of the treated part is 106ha and into Chaovang Stream. (3) Nanjinglu drainage svstem a. Location: right bank of Chaovang Stream b. Scope: d800-1200mm, L=600m c. Content: reinforced concrete pipe d. Bencfit: The catchment of the treated part is 15 1 ha and into Chaovang Stream. (4) Hangzhoulu drainagc system a. Location: right bank of Chaoyang Stream b. Scope: d800-1200mm. L=6I Om c. Content: reinforced concretc pipe d. Bencfit: The catchmcnt of the trcated part is 64ha and into Erkeng Stream (5) Chaovanglu drainage system a Location: right bank of Chaoyang Strcam b. Scopc: d lOOOmm. L=470m c Content. reiniforccd concrctc pipc d Benefit: The catchmcnt of the trcated part is 46ha and into Erkecng Strcam (() Suzhoutil drainage system a Location- right bank of Cliaovang Strcam b. Scope d I 000-14OOmm. L=5 30m c. Content rcin forccd concrctc pipc (7) Huadonglu drainagc system a. Location right bank of Chaoyang Strcam b. Scope. dXOOmm. L=900m c. Conteit: rcinforced concrctc pipc d Bencfit: The catchment of thc trcated part is 165ha and into Zliupaichiong StrCaml (8) Jinanlu drainage s\stcm a Location right bank of Chaovanig Strcam b. Scope d800tumr. L=600m c. Conitenlt reinforced conicretc pipe d. Benefit: Tihc catchmcnt of thc treatcd part is l O8ha and into Zhupaicholnu Strcam (9) X'inggii_glu drainage s\stem a. Location. Left bank of Chaoyang Strcam 14 b. Scope: d 1000- [200nun, L= 1800m c. Content: reinforced concrete pipe d. Benefit: The catchment of the treated part is 72ha and into Zhupaichong Stream. (10) Chaovanglu drainage system a. Location: Left bank of Chaovang Stream b. Scope: d800-1800mrn, L=840m c. Content: reinforced concrete pipe d. Benefit: Thc catchment of the treated part is 108ha and into Zhupaichong Stream. (I 1) Gaofenglu drainagc svstem a. Location: Left bank of Chaovang Stream b. Scope: d800-lOOOmmn, L=300m c. Content: reinforced concrete pipe (12) Xinhualu drainage system a. Location: Left bank of Chaovang Stream b. Scope: d8OO-10Ommn, L=750m c. Content: reinforced concrete pipe ( 13) Beininglu drainage system a. Location: Left bank of Chaovang Stream b. Scope: d800-lOOOmm, L=350m c. Content: reinforced concrete pipe (14) Minshenglu drainage system a. Location: right bank of Cliaovang Stream b. Scope: d800-IOOOmm. L=300ni c Conitent: reinforced concrcte pipe (I 5) GonighclL drainagc s stcm a Location: Left bank of Cihaovanig Stream b. Scope: d1400mm. L=350m c. Conttent: reinforced concrcte pipc (16) Zhongshanlu drainage system a Location: south of Minzudadao b. Scope: dSOO- I000mm. L-900m C. Contett: reinforced concrcte pipe ( 7) Naanguolu drainage system a. Location south of Minzudadao tb. Scopc: d800nmitm. L=320m c. Content: reinforced concrcte pipe (I 8) Kanglelu drainage system a Location: south of Minzudadao b. Scope: d800nmnm. L=250m c. Content: reinforced concrete pipc I5 (19) Baoailu drainage system a. Location: south of Minzudadao b. Scopc: d800- 1000mm, L=250m c. Content: reinforced concrete pipe (20) Jianzhenglu drainagc sv'stem a. Location: south of Minzudadao b. Scopc: dlO00-1200mnm. L=350m c. Content: reinforced concrete pipe (2 1) Nanhuanlu drainage svstem a. Location: south of Minzudadao b. Scope: d I000-1200nm. L=340m c Content: reinforced concretc pipe (22) Anningxiaoqu pumping station a. Location: Anningxiaoqu b Scope: Q=l m;/s. H=5m. c. Content: Im'/s. high 5m 2.1 . 5 Schedule of'the project I The Chaovang Stream comprehensive treatment broicct 1994-1997: Feasibilltv study. asscssment of the project. talks on the loan. initial and detailed desigining. civil engineering and technical and equipment preparation. preparation for land requisitioni and inhabitant rcsetticment. calling for tcnders and prcparation to bcgin the constructioii of the project. 11)(7-1998. Treatnicit of the lower reaches of teic Chaovang Strcam inver bed and thc constructioni of thc waste wvatcr interccption projcct I 998-200 1: Treatmcnt of thc middle reaches of the Cliaovang Stream nriver bed Constnmction of the waste water transfer and treatmcnt projcct of the Chaovang Stream Dcc.. 2DO1: Complction of the treatmncti of thc Chaovang Stream rivcr bcd project, complction of all thc pipc nretwork project. and itic completion. adjusting and checking of wastc %water puniping station 20012: Ocrall operation of waste watcr collccting and transfer projcct 2 The drainace piPC network svstcm of the urban areas of Nanning City Sept.. I1996-Aug.. 1 9Q7 Compilling and study of feasibility report. assessment of thc pro ect and talks on thic loan Jaii.. I 997-Sept . 1 '(98.: Inilial design and its approval. compiling constniction charts for approval. comilpililng civil enginericng and equipmcnt plan for approval. and compiling of papers for contractors cxamination and calling for tenders Sept.. 1997-Apr.. 2001: renovation of rain water and sew%age drainage systein of thc urban nareas and tihe construction of additional rain %vater wells and checkinig wells. If, 2.1. 6 Investment of the project The total amount of investment for the comprehensive environmental treatment project of the Chaoyang Stream in Nanning Citx amounts to 573.04 million vuan (RMB). of which the treatment of the Chaoyang Stream takes up 250.46 million *uan, drainage system of the urban areas takes up 186.94 million !uan. and building removal and inhabitants resettlement take up 135.58 million yuan. (See Table 2-1-1.) Table 2-1-1 investment for the comprehensive environmental treatment project of the Chaoyang Stream in Nanning City No Project [ain Content Investment (10' I ___ ____ _____ ____ _____ ____ _____ __ j yuan) I The Chaovang Stream Treatment Project (1) Engineering of renovation of the nver course Renovation of the fiver course. water supplement 13004 (2) intcreeptison System of vaste water dl200-d2000rnm C 2600 - 2000- 0 3800 2400tnm L=6.3kn (3) pipeline of passing nver L=0.5km (4) liangbei nain sewer 02 3800 - 2400nun L=4 2km (5) Wastcr waler raising pump station 2 7ni3/s (one) (6) waste waler treating plant 2.6 - lO4m'!d subtotal ' 5046 2 Drainage svst:nt project in Nanniniig (I) Rjitnitrik 13 rain mitaini trunks. d600J-d2(J(J0nin (2 1400 I I'806 1000-C 2800 ,I 800mm (2) Se:wer pipelitic 2 sewcr pip.lines d600 - 900mil S '7 (1) rcnonation or1pirpeline in Old citv 21 pipeline dX00-d l800Smm one pump sUt1tin :597 (4) equipments fir 1aititaaiaing the pipelignc tuniumcr of vrieIiCe 12 1164 (5) mtatitcnan1cc if the pipeline lengtih 28.3km 1300 (6) subtotal S694 3 other tlousc removal and inhabitant rescttloviient 13552 4 total 7304 2.2 Production technology 2.2. 1 Cotnpreclinsivc 7rcatnwent of l'h Chanyang Stream I. Treatment of the river bed The plan states open canal combined with covered canal shall be constructed.. Following figures arc for the concrete technology (I) Open canal part: Youai Bridge -- Dakengkou 13 Renovation of the river bed - Ecological recoverv River wae Dredge of (Temporary piling - (2) Covered canal part: Heavv Machine Building Plant - Youai Bridge River watr Dredgeof Fpelin [iBa Recoverv (or usage) | empsing_ of the land surface Temporarv piling of sediment -. transportation disposal site 2 Technologv of the waste water treatin2, plant Primary activated sludge method shall be adopted for the waste water treating plant. (See Fig 2-5). (1) Pretreatment of waste water: Scalping grizzlv screen, mechanical screen is to be used: inlet water pumping house, fine screen. Aerated detritus pit (2) Primarv treatment of waste water: Primarv classifier, aeration basin. secondarv classifier .sludge reverse flow pumping house, and air pumping house (3) Sludge treatment: Sludge condesing pit,. sludge dehvdration house, sludge storage shed and sludge treating canal 3 Waste water intCrcepting and collecting system Concrete technology of the waste water intercepting and collecting svstcm is as follows: Pulling down ad [ pipeline back restore of iiiovel of buildings laying ground surface 4 Rl-er-crossing of the pipes Pipe sink-ing method shall be used. 2.2 2 7TL-chneox!/' of the drainage sytewn in u(rban areas of Nanning City, The technology of laying of pipe network for rain watcr and waste water and thc renovation of old drainage system is as folloxs: Sirface ditcl pipeline back restoring of removing digging laying filling grounid surface 18 Open canal part -River bed renovation -- ecological restoration Emptying of the river water --digging of sediments -| -(temporary piling of sediments) -- transportation --disposing site Closed conduit part pipeline laying --backfilling --restoration (or utilization) of the ground surfacc Emptying of the river water --digging of the sediments- 1(temporary piling of sediments) -transportalion -disposing sitc Fig. 2-3-2 Engineering of the renovation of the river coursc 2.3 Mlajor pollution sources and their discharging of pollutants 2. I Conmprehenisive 7reatment of the Chaovang Stream I Major pollutied sources during the construction of the project (I) Sediment of the Chaoyang Stream. cast away soil dunngthe construction, and garbage The renovation of the river course shall clean awav a total of 0.2 million m3 of sludge. The disposal of such an amount of sludgc is a sensitive problem Secondary pollution mav easily appcar if it is not handled properly. The construction of the wraste water interception system \ill produce a ccrtain amount of soil to be cast away. Construction garbage mainly consists of broken bricks, broken pieces of asphalt road surface. concrete blocks, and w\-aste wood bits. and so on. (2) Construction noise The engineering of the renovation of the river course and the laving of waste water pipe lines are all to be carried out in the central part of the city. downtown district and not far from public transportation routes, and the constriction tvill last a fairly long time. thus the noise of construction machines shall cause much impact. As the construction takes a fairly long time. this remains a sensitive problem. This is also a sensitive problem. See Table 2-3-1 for the intensitv of construction machines. Table 2-3-1 Intensity of noise of different sources during construction Noisc sourcc Noisc intensity dB(A) Noisc sourcc Noise intenlsity dB(A) Air drill .10( Soil shifted 94 Puddle mi\er 98 Road scraper 94 Scaper pan 96 Bullodozer 92 Exca%azor 95 Air comprcssor 92 ( Raiscd dust Besides the raiscd dust which may bc causcd from the piling and transportation of the 0 2 million m; of sludgc dug up. thc earthwork to bc dug during the construction of the waste water intcrceptioni projcct and the laying of pipc lincs and its transportation will causc raiscd dust It shall affcct certain rangcs of the tw%o sidcs along thc routc of construction and may involvc the x%-hole citx of Nanming. 2. Mlajor polluotion sources and thcir discharging of pollutants during operation of the projcct (I ) x%aste water After the compiction of the comprehensive environmental treatment of the Chaoyang Strcamii prolect. waste wxatcr form an area of 258 000m3/d will flow to the Jiangnan waste watcr treating plant throtigih the trunk pipe line in Jiangnan. thcn dischargcd into the Yongjiang Ri%er after primary treatment. See Tablc 2-3-2 for tihe wvaste water compositioni of the project. 20 Table 2-3-2 Amount of Waste Water of Areas in the project (1994) Catchmuen Population Daliv sewage rIndustnal waste w aler Total 1000 I OOOOm3/d % iOOOOm3/d e m10000n3/d R. Chaovang Strcam 271 81.3 69.9 35 30 1 116.3 R. Erken- 147 44 1 49.0 45.9 5! 0 90 Xixiangtang 72 26 48.5 22.9 44.5 (2). Solid waste Sludge produced in the production of the vaste vater treating plant. mainly of digested and deh'vdrated clay cakes and inorganic matters from the detracts chamber. Whether the clay cakes contain harrnful substances or pollution shall be deternined by the quality of the water draw%n in. But daily output clay cakes is fairly small. (3). Waste gas Waste gas mainlv consists of the biogas produced in thc sludge digestion pool, which is of an unpleasant smell and, as the waste water treating plant is located in the windward direction of the citv, it poses as a negative factor. (4). Noisc Waste water pumping station produces much noise and it is located in downtown area. thus much impact will be caused. 2.3. 2 Drai7age s vvent it in urban areas I Major pollution sources during construction of the project (M). Raiscd dust Raiscd dust fomis an iiiportant pollution source during thc constnIctiont of thc projcCt and is an issue mucil conccnied by the people. Tihc brcaking Up of thc road surface. carthwork to be dug. laying of pipe lines and the transportation and piling of materials will all produce raised dust. It will influcnicc arcas along the transpiration routc and even the \holc of Lirbani areas of the citv. (2). Noise As the laying of drainace pipe line system will bc carried otit in the urbaln arcas where the populatioil is dcnse and traffic hcavv. and as the construction will last a fairly long time, nIoise produccd by conistiuctioIn machines anid transportation vchiclcs xvill have muclh imiipact. Tnis is also a sensitive probleim. Please refer to Table 2- -I fourth intcnsitv of noise sourccs. (3). Sludgc and castawa\ soil The amounit of sludge to bc dredgcd amounts to 52 000())1 Its transportation an disposal arc an issuc deserving muchi attentioni. If not properly hiandlcd. secondary pollution will bc causcd. Thic laying of pipc line nct\%ork. temporary occupation of road surface. and the soil to be cast away during the earth\ork. all %%fll produce sonic negative impact on the environmcnit 2. Major pollutioni sources durinig thc operation of the projcct (I). Non-point pollution sourccs 21 Pollutants like surface silt, nutritious and organic matters will enter surface water bodies with surface runoff through drainage pipe lines and pollute the environment. As the capital of the region, Nanning is its political. cultural and commercial center With not much industry. So non-point pollution load caused by rain runoff takes up a high percentagc. It should be a key link in controlling wvater pollution. (2). Industrial waste ws-ater Nanzichong area in Jiangnan District is the major industrial area of Nanning. Major pollution sources include over a dozen factonres and enterprises such as Nanning Candy Paper Factory, Nanning Chemical Group and the lysine factory. As large amount of industrial waste water is discharged into the Tingzichong Stream. its water bodv is now heavily polluted. black and smelly. It also affects the Yongjiang River water quality as the former directly flows into the latter. The protect plans to lay waste water pipe lines in Tinghong Road and Baisha Avenue so as to collect industrial waste wvater from the Tingzichong area to be transfcrred to the planned Jiangnan waste water treating plant, thus restoring the function of the watcr body of the Tingzicheng Stream and improve the water qualitv of the Yongjiang River. Sec Table 2-3-3 for the amount of wastc water from major industrial sources and their quality. Table 2-3-3 Main pollutant sources in Tinzichong Industrial Distract uaste water SS COD BO1D5 Naiie or factorv 100(IO 3/d u/d ing/l tId m/1 L/d III/l Nainning Clicimiical Group 29.1 18 64 641 7.84 269 Ninning Sugar rctnen 29. 9 19.61 656 39.51 1;21 9.85 3'9 WLine Factorv. 7 8 0 82 1l0 1 22 156 ( 47 6( NanningTrannmr 6.5 8 14 1252 9.96 1532 3,17 488 Nanninmg Silk Spinning :Factorv 4.5 0 69 1531 0.42 9 0 26 58 Nanliliig Sieliting planit 0 4 0 (02 5 0O (5 I 2 _ I-otal 7S.2 22 3. General situation of the environment of the area of the proposed project 3.1 Natural environment 3. 1.1 Geographic location An important city along the southwest border regions of China, the city of Nanning is located in the southwest of China, serving as the capital of the Guangxi Zhuang Autonomous Region, at 22 10'--20030'N and 107045'--108045'E. The city proper has an area of 1 9388km. and the constructed urban part is about 80km 2(Fig 3-1). 31. 2 Topographic katires The city of Nanning is located in the Nanning Basin along the banks of the Yongjiang River. Thc basin is of an olive's shape. stretching NNE. The land is flat with a ground surface level of 71.7 - 75.67m (abovc thc Yellow Sea level). The Yongjiang Riverflowvs through the southwvest of the urban areas of Nanning, dividing the city into a northern part and a southern part. The Yongjiang River fonns six terraces in the ccntral part of the basin: Terraces of Gradcs I and 11 are intrastronmato terraces and Gradcs Ill and IV arc foundation terraccs. all with didactic structure. Most of the Chaovang Stream flows on the Grade 1I terraces of the Yongiang River. and parn of it on Gradc I tcrraces. The drainage area of thc Chaoyang Strcam inclliecs from the north tO thc soutl. To its nortlh risc tIIC Naanshall Mountains of the Nanning basin and to its south is thic urban arca of the city. The Chaovang Strcami flo-ws throughi the urban areas of thic city to enipty into the Yongjiang Rivcr. 3. 1 3 Suirfrice uiater and 'lrOunin/ watater The Yongjiang River is thc largcst rivcr running through the citx of Nanning. 480m vwide at the Nanning section. a% Craging 300m. with abundant amount of water and a stablc rivcr bcd The averagc aniual runoff over the ycars of the Yongjianr River is 124.6 billion nm'/s. The drainage arca of uppcr 'ongiaang Rivcr is 78228 kmi. Major tributaries of the Yongjiang River distributed in Nantilng includc the Zhupaichong Stream. the Tingzichong Strcam. the Chaovang Strcam. the Erkctig Strcami. the Liangfcng Stream. the Xinvu Strcam. thc Keli Strcam. and the Shilling Strearn. of w\hich the Liangfcng Stream is the longcst. followed by the Xinvu Stream and thc Zhtipaicliong Strcam. whose rainvatcr catchmcnt areas are all over 100km2. Other tributaries are fairlv short wvith rainwater catchmnent arca under 100km2. wvhich are distributed to the banks of the Yongjiang Rivcr and flowv into thc Yongiiang River in the urban arcas of thie cit (sCC l'able 3-1-1). Major lakes include thc Nanhiu Lake. which has an area of I .6kmn. thc Xianesi Lake. and the Bailong Park. 23 -- Location of Nanning city <7> \130Xt 0' t \ t9F~~~~~~~~'-',>% ;' --fS2 j ) I ' ! j X , N > w -- ! - -i- I\ K- 0 , 8 01'141t StreaX t\ .--, .i.X$' :e*< 7~~~- 4# ,--J [ ( ,I j' 10 '.~* , ,:'- '7-D- I.i/dn Rodf oL X1 , LI. . . . .. . . ... . . . .. . . . . .., e~ Feuhuaa~i ' 7I:Nann-ingIrzdd C#: Nan in~~~~~~~~~~ Table 3-i-1 Parameters of Major Tributaries of the Yongjiang River River Catchment area Length Average gradient Runoff Maximum Runotl kaf km O.k Coefficient a C (m /s) Zhupaichong 117 35.9 2 41 0.75 Xinvlt 132 29.3 2 96 0.75 410 Keli 66 34.3 4 61 0 75 635 Ferhiluang 24 16.8 I 6'8 0 75 269 Ximiniiiglhtu 35 8.8 7' 0.75 430 Shillng 31 8.6 1 82 0.60 Shipu 9 7.2 9 S8 0.60 Chaovang 24 4- 13.5 2 16 0.70 13 5 Erkeii II 6.8 2 58 0.70 98 Tin-7ichong 10 7.5 4 43 0.70 83 Note: based on data of the report of flood resisting plan of thc city Ground water in the Nanning Basin can be divided into 1. II. and [II types. Type I. pore water of the loosc deposits of the Quaternary System of the Nanning Basin. which has an area of about 138 km2. with flat landscape. distributed in the Grade I, 11. and III terraces of the Yongiang River. Tpe [Il: red beds pore crack watcr, distributed in hilly terraccs at the fringe of the basin and Grade IV, V, and VI tcrraces and destructionial tcrraces of the Yongliang River. Tpc IlIl: fragmental rock crack water in thc lown mountains and hills around the basin, where ground water is storcd in thc cracks of rocks, of phreatic water ty pe. 3,1. 4 Ch('irat Thc citv of Nannmilg is locatcd to the south of the Tropic of Cancer and belongs to the subtropics zone. with rich rainfall and sunshine The climate there is %%Ct. t-ith a long suLiniier but no winter. Frost-frcc davs in a %car number as manm as 343, with 1 .827.0h of sunishiine and avcragc atmosphere prcssurc of 1 004.1 milhbar (I) Air temperature Thc averagc air temperature of thic arca is 2 1.6'C. thc highcst in July (averaging 28.3TC over thc years). the lowest in January (averaging I2.X"C over the ycars). with the cxtreme higi of 40.ATC (May 9th. 1958) and the extremc lo%% of-2. 1"C (January 12. 19 5). (2) Prccipitation The cit\ of Nanniing has rich rainfall. a%craging 1.2400mm/a (data ovcr 30 scars). wvith the highiest 1.970mm/a (1952 data) and the lo'%cst '52.9nmn/a (1952 data). Influcilced the vear throughi by wvanm air masses from the oceans and ininerland air miasses. rainfall is conceiltrated in the flood period from May to Septeimber. lhen tic rainfall accounits for about 72%yo of thc annilal total. The retirning of warm air masses from the occans starting in May brinig along storms, whilch often conies abruptly. The possibility of daily niaximumtii stornm in May to June is 25 about 45%. Influenced by typhoons. August and Septembcr witness another penrod of heavy rains. The rainfall in June is the highest in the vear (averaging 217.5mnm/d over the years) and that in December is the loxvest (averaging 25 .9mnn/d oxver the vears). Annual evaporation reaches 1,218.6mm (data of 25 vears), with an avcrage annual relative humiditv of 79%. Sunshine duration reaches 1,827.OhI/a, with a sunshine rate of 4 1.5%. (3) Wind The average annual wind speed is 1 .5-2.3mIs, and there is no distinct fluctuation betwveen different seasons, with that in February to July a little higher than that of other months. The maximum wind speed is 18.Orn./s (NNE, August 11. 1962), and the extreme high 31.5m/s (SSW, July 4, 1971). Northeast wind prevails in winter and southeast w%ind prevails in summer. 3.2 General situation of its ecological environment The total area of forests of the city is 275.300ha. with a coveragc rate of 39.1%. and a coverage ratc of greenland is 3 1.6%. There arc over 3,000 species of plants in Nanning. Among wild plants over 150 species are useful, including perfume oil plants, oil bearing plants. starch plants. tanning containing plants, fiber plants. medical plants, and omamcntal plants. Timber trecs include pine, fir. guni, and oak. Among precious trees is -crythropjloeuni ferdii. and among ornamental plants is the wvorld famous rare golden camcilia (based on information from). There are no rare spccies of wildlife or plant living in the arca to be asscssed 3.3 Social environmncit J. S. l Adrinrs(rative division Thc city of Nanning lias the jurisdiction ovcr 8 districts and counties. with a total arca of 10 029kmn. of xvhichi I 939kn1 is urban area. The fi%e urban districts are Xingning. Xincheng. Yoongxin, Chcngbei, and Jiangnani, and the two counties arc Yongning and Wuming. The cite has a population of 1.07 million (1994), Of which 0.76 million living in the urban area. 3.3.2 Characteristics of the city Thc citx of Nanning is thc Capital of the Guanexi Zhuanlg Autonomous Regioll and is the political, economilc. and cultural ccntcr of the rcgion. The city began to opcn to the outside %%orld in 1992 with the sanction of thc Statc Council. Nanning is also an important city in southwest China witlh very advantageous gcographic location: it sits at the banik of the Yonijianig Rivcr, not far from the sca. facing soutileast Asia and backed by southwest China. Along vitilI the completioni of the Nanfang Railway and the Nankun Rail%vax and the opening of air traffic, Nanning is becoming the thoroughfare to thie sea for the four provinces in southwest China: Yunnan, Guizhou. Sichuan. and Guangxi. TeIC city's function and radiation 26 capacity Hvill increase wvith cverv passing year, and its si'nificancc in politics and economy wvill increase, too. 3. 3.3 Agriculture The city of Nanning has an area of 10 029km: (including the t-wo counties). wvith 167 420ha of farmiland. of which paddy field 93 865ha. and non irrigated farmland 73 370ha. The area actually sewn with grains is 94 5O0ha, and sugarcane filed takcs up I I 340ha.. The total agricultural output valuc in 1993 reached 2.65 billion yuan (1990 fixed price), showing an increase of 7.2% over the previous vear. The total output of grains is 746,900t, that of sugar cane 3.116 million t, that of meat 102.600t. and vegetables 5 19,500t (according to the government's wvork report of 1994). 3. 3. Industri' The total output valuc of industry reached 10.9 billion yuan (1990 pnce) in 1994, showving an increase of 18.3% over that of 1993. Thc developing rate of light industry is far quicker than thosc of heavy industrv and agriculture. The total output value of light industry reached 5.525 billion vuan in 1993. and that of heavv industryv was 2.782 billion vuan. Major industrial products include coal. cement, glass pancs. sugar. cigarettes. wine, and walking tractors. Tertiarv industry has undergone rapid development in recent ycars. The GNP of the whole citv in 1994 increascd 2 1.2% ovcr that of 1993. of which primary industry incrcased by 7%. secondarv industry increascd by 24.42%. while ternarv industrv increased bv 24.44%. The tlhree accounted respectively for 16.88%. 39 12% and 44 20'%. of the GNP. The number of total industrial employee was I 447 700 (1993 figure). of x%litch those employed by primary industrv. seconcdary industrv and tertiarv industry respectivclk accounited for 53 64%. 19.78. anld 26.58% 3.3. 5 resent strae of infrtasructure 1. Water supply and sewage system of thic citv Therc are four tap water mills in Naining (Lintie. X;iiao. Hcinani and Xhun\ao). Anotiher at Clienchuni shall bc built according to plan. All the tap w-atcr nilils draw water from the Yongjiang River. get it treatcd bcfore scndinig it out. Thlsc iiitlls supply all the water for the inhabitants' daily use and part of mdtistrial watcr. The total production capacity of the water mills is 594 OOOt/d. supplying a total of 250 69 milihon t/a of "watcr (1993). Sonic of the cnterpriscs have thcir own water mills. and four of thenm arc of fairly largc scalc. Thc total lenigthi of tap water pipclinc was 427km in 1993 852 001( iniiabitants arc now using tap water. avcrage constiming 412.6L/d of watcr per capita. ThC cit1t has a total of 204kmi of sewage pipcline. The city produces 200.55 million t/a of waste water. of which daily scwage amounts to 97.78 millioni t/a. Most of the waste \\utcr is directlv dischiarged into the tributaries of the Yongiang River without any trcatment, so the 27 tributaries of the Yongjiang River are heavilv polluted. The water looks blackish and stinks. The watcrbodv of the Yongjiang River itself is also polluted to a certain degree, severelv affccting the quality of water supplied by the water mills. (2) Flood controlling system Nanning has been suffering from serious and frequent floods. Backwvard flow often happcns to flood the cityv when the wvater level of the Yongjiang River nses. As the scxver and conduit are narrow and the tributaries do not have sufficient flood discharge capacity, backwater will happen to cause flood in the city during storms. The city of Nanning faces great threat when outside and inside flood happens at the same time. The length of the section of embankment in Nanning along the Yongiang River is 34km. There are flood prevention sluice gates at the inlets w-here its tributaries flow into the Yongjiang River. and pump stations control the flood level. (3)Public transportation Second rate highwi-ays like Nanbei. Nanwu and Nanvu have been built since.the beginning of the 90's. And the city government planned in 1996t o renovate several roads leading out of the city like Mingxiou Road. Youaibei Road, build a new road: Changhu Road, extend Wangzhoulin Road. Baisha Avenue. the east section of Dongge Road. and Binhai Road. Thc total length of existing public transportation has reached 5 53km (table 3-2) Table 3-3-1 Quantities of Transportation, 1993 Goods (I 000t) Persons 1.00 A) person/a) Raillav 2.840 3.840 | lagohwxTiv 447.160 20.140 Water coourse 1.590 .30 EA _viati_on6 I 8.64() It)) Nanning has no"w an airport. which links many air routes at honic and abroad. But the scale of the airport is a far crv from what the transportation hub in south"xest China calls for. Tlicrc are along hc Yongjiang Rivcr many dockyards. which facilitates convenient cast-west transportation. 3.4 People's life quality The constnicted arca of the city of Nanning has developed to rcach 80km . vith a urban population of 1.07 million bV the cnd of 1994. of which 0.76 million arc non-agricultural population. The GNP reached 10.3 billion ysuan in 1994. Pcople's living standard lias becn raiscd along with the developmcnt of the ccononiv. Thc average daily living inconic of to.vn iilnabitants rcachcd 4.099 vuan/a and the pcr capita nct incomc of farmcrs 1.306 vuan/a. %khich mcanis an incrcase respectivcl of 16.74% and 10.09% over thc year before w'ith deductionl of thc clements caused by inflation (according to the government's report on its "ork). 28 There are now 8 parks in Nanning Citv with a total area of 333ha, which receive a total of 4.86 million person/a. Thc area of parks and green land have reached 2.000ha, green areas of the constructed part havc reached 2.289ha, avcraging 4.3mr per capita, wvith a green coverage of 31.6% (1993). 3.5 Environmental quality 3.5. 1 Water environmental qualitY I Background situation of the quality of surface wvater (I). Background situation of wvater quality of the Chaov ang Strcam, the Erkeng Stream, the Zhupaichong Stream. the Tingzichong Strcam and the Shuitangjiang Stream and its assessment The six tributarics of the Yongjiang River-- the Chaoyang Stream, the Erkeng Stream, the Zhupaichong Stream, the Xinyujiang Stream. the Tingzichong Stream and the S-huitangjiang Stream--reccive the industrial and sewage from the urban areas of the city of Nanning. The first four lie to the south of the Yongjiang River and the last twvo to its north. A. Monitored results and analysis of the water qualitv The results monitored over the Chaovang Stream. the Erkeng Stream, and the Zhupaichong Stream. Analvsis in 1994 shown in Tables 3-5-1 and 3-2 reveal hat the major items exceeding the standard (for Gradc V of surfacc water) are the DO, COD and BOD5. NH3-N, and oil. This suggests that the major pollutants affecting the threc rivers are organic oxygen consuming ones. Table 3-5-1 Results of Monitoring the Cliaoyang Stream and Other Rivers, (1994) Unit: mg/L (except thiat of p1i and otherwise noted) Iteinl Chamovzniu , I rkcn2 Zhtzpalchon2 'I'igzichonig Slituitilg ___ _ 7.22 621 7(iS 847 90( SS 1037 56 0 121 7 1598 462 0 Ilardness(CT) 103 4 11 7 82.47 135.7 231.8 CODCr 243.6 195 ( I 13 75 1157.1 284.8 Bl0D5 141 9 nd 30 ;4 237 4 65.9 DO 0.o0 nd 1. 9 2 06 3.17 IN]13-N 2414 123 S 35 6 97 18.8( N102-N 0) t)fiX; () 7066 () 0 06( ( lII 00 27 N0.1-N o 54 0 552 n 571 107 1.371 S04 I 66 0 24 tid (105 0.03 ClE 54 f 2 I4 32.23 556 (4 182 10 CN () 004 0.1 id ()(09 (0010 29 Counted Table 3-5-1 Item Chao ang Erk-eng Zhupaichong Ting7ichong Shuitang Plhenol 0.032 0.041 0.051 0.025 0.016 Hg (pg/L) 1 037 0.20 0.227 0.253 0.283 As nd 0.015 nd nd nd T-Cr nd nd id () 02s nd Cri 6 nd nd nd nd nd Cu (g/L) 2.0 5.0 2.0 17.0 0.11 Pb (pg/L) 0.037 0.01 nd 0.087 nd Zn 0.085 0041 0.012 0.060 0.048 Cd (10-3I1.) 0.002 nd 0.0017 0 008 0.008 Oil 4 158 41.58 2.52 7.78 23.89 B. Assessment of the water quality ovcr the years T-he standard for Grade V surface water set in Documcnt GB3838-88 -Environmental Quality Standard of Surface Water" was used in the assessment the water quality . As for NH3-N, the reconimended standard of 1.0 Ig/L was used. The method of average value of comprehensive pollution indcx was used in assessment. The assessment of the water quality is as follows: a. The pollution of the Zhupaichong Strcam was comparatively light, between lightly polluted and heavily polluted. both the Chaoyang Stream and the Erkeng Strcam xvcre heavily polluted to seriously polluted. and the comprehensive pollution indexcs of the formner is higher than thosc of thc lattcr. The ordcr of seriousness of pollution is The Chaoyang Stranm > the Erkeng Strcam > the Zhupaicihong Stream. b. Thc comprehensive pollution indexes of organic pollutants account for ovcr 90% of the total. while those of heavN mctals account for only a small ratio So the pollution of the threce rivcrs is mainly caused by organic mattcrs. c. Analysis of their comprchensivc pollution indcxcs shows that the pollution of the Chaoyang Stream. Erkeng Strcam. Zlhupaichong Stream. Tingzichong Strcam and Shuitangjiang Stream arc getting worse ycar by year. This is caused by the rapid devclopment of econom' and the increasc of population of the invcstigatcd regions wvithout syxnchronized waste water treating facilities. (2) GeIIeral situation of watcr qualitv of the Nanning segment of the Yongjiang River The Yongjiang River provides the maini sourcc of w atcr for the city of Nanning. It has a total Icngthi of I 34km and the its upper strcams arc the Yongiiang River in Yunnan Provincc and thc Zuojiang Rivcr it \'iet Nam. To monitor thc changc of tts x\ater qualittv, cnvironmcntal protection institutions chiosc a contrasting scction, a control section. and a cutting section at Laokou bceforc it flows into thc citv. both at thIC Slhuitangjianlg Strean where it flows out of the citv and at I'Lmiao in its lower reach 30 250 200 - 150 iug/1 loo'-X/ 1-30D1 100 50 , 0 Chaoyangxi Zhupaichong l'in-7ichon2 Shuitangjiang 25 20 m2/L 315 m 13-NN 10 S o Chaoyangxi Erkeng Zhupaicliong l'ingzclhoiig Shuttang tlang 50 40 30 mgI '~ 70\ioil 20 Ol Chi.loyaligxm E.rk:n Zhulpaichlong 111°7i:izlioitt, Slitittanl ilanig 1200 10( 12-P. 00 80()/\ IngI. 60)0 /4- \) + l) 400 200 ChalowangI l.irke:tg Zhipaicihons 1'inUlcilOing Shult,: n,:: Fig. 3-2 Results of Monitoring thc Chaovang Stream andl Other Strc;tms I1 A. Results monitored and their anal-sis Table 3-5-2 and Fig. 3-3 show the results monitored at those sections in 1992-94 The data reveal that the wvater quality of the Yongjiang River is fairly good before it flows into the urban area of Nanning. Most items are within the standard for Grade [II surface water set by the state, except a few items (SS, oil and NH3-N). Its water quality remarkablv deteriorates to worse than Grade [11 surface water after it flowvs through the urban areas is it is affected by the waste water discharged into it, B. Assessment of water qualitv The order of wvater quality pollution: Shuitangiang > Pumiao >Laokou. Table 3-5-2 Monitored Results of the Shuitang Stream on the Yongjiang River, 1992-1994 unit: mg/L (except that of pH and other%%ise noted) I[ten lokou Shuitangjiang Pumiao 1992 1993 1994 1992 1993 1994 1992 1993 1994 pEI 8.24 8.27 S. IS S. IS 8.02 8.03 SS 13S.4 60.9 133.0 49 6 102.8 66.4 74.30 64.9 58.7 lI ardesz (G) 73.75 77.74 7S.14 79 73 76 69 78 13 IX) 7.18 6.72 6.65 5.61 5.34 5.11 5.38 4.63 4.80 C(oD.\Itl 2.17 2.75 3.48 3.31 4.88 4.60 2.75 3.50 3 76 130)D 0.63 0.53 1.2 1.84 1.87 2.28 0 92 0 98 1.1 NiXl-N 0 065 0 068 0094- 0.539 0 573 0 597 0 374 0 444 0 505 NO->-N 0 010 0 0012 0.015 0 01l 0 1I 0.025 0 016 0.0oS 0.(19 NOi.N 0 5x7 0634 0.598 0.574 0.597 0 583 0 597 061S 0.573 P'henol 00(1) 0001 0.001 0001 0001 0.001 0 001 0.001 0.001 C\ 0.002 0 02 0.O0I 0002 0 002 0.002 o 002 0 002 0.002 _ _ 0.0039 0.0037 0.004 0 0043 0.0055 0.005 0.0036 0.0035 0.005 I ig pg 1. 0.05 0 05 0.05 0.05 0.15 0.05 0n II 0 05 0.05 Cr 0 0.002 0002 0.002 0 002 (.()02 0.002 0.002 O 002 0.002 1P. pgL 0.8 0 8 1.0 0.8 0( 0. 08 o 0 8 1.0 C d 1ig 1. 0.035 0.(35 0.035 0o035 0.035 0.o 0 035 0.035 0.8 OI1 0.034 ) 026 0.02 0 116 0.922 0.002 0 025 0.025 0.02 . ndutiavitv 232 0 247 260 243 251 248 244 7 254 259 The wvatcr quality at thc cutting section. i.c. Pumiao section is a littic bctter than that of Shutatialnjiang scction. but not as good as that of the contrasting section, stiggestiig that l)ollutants discharged into the river from the citv of Nanning have been wholly degraded and self cleaned at Pumiao of Yongjiang County, still posing as a thrcat to the lifc of inihabitants in 32 Pumiao and its lowvcr reaches. Therefore, pollutants discharged by the city of Nanning must bc controlled or cut. ElCOD E BOD ONO'- 92 93 94 92 93 94 92 93 94 Laokott Shuitanlipang Pirniao Fig 3-3 The Results Monitored at Those Sections of the Yongjiang River 2 Monitonrng and assessment of existing water environmental quality (1). That of the construction area The areas investigated mainly include the Chaovang Stream. the Erkeng Stream. thc Zhupaichong Strcam, and the Nanning scgment of the Yongjiang River. All together 9 monitoring polints wvere chosen, of which 3 werc on thc Chaoxang Strcam (rcspectively at its upper, middle and lower rcaches), one on thc Erkeng Stream and 2 on the Zhupaichong Strcam (at its upper and lower rcachcs). Another monitoring point was chosen at the junction where tiic three tributaries flow into the Y'ongjiang Rivcr. At the samc time hydrological data and water samples at the outicts of the water mills as well as data of watcr quality of the upper and lo"xer reachies of the Yongjiang River xNere also collccted Sce Fig 3-2-1 for thc localities of the monitoring points A. Results of watcr quality monitored NMonitored rcsults arc lists in Table 3-5-3. B Asscssmcnt of watcr quality See Tabic 3-5-4 for thc pollution indcx of the itcms of tile Cilaovang Strcam. the Erkcng Stream and thc Zhupaicihonig Stream. The table reveals that thc index of items likc COD. BOD;. NH-.-N. coli. Hg and petroleum all cxcecd the standard. The comprchensivc index is 4 QS. being seniously polluted. Thc index ot' COD. BOD;. NH;-N. coli. Hg and pctrolcuml in the Erkcng Stream all exceed tilh standard. Thic comprchcnsivc index is 2.68, being seriously pollutcd. Tnhc index of COD. BOD,. NH.-N. coli. Hg and petrolctum in thc Zhtipaichonig Strcam all cxceed tihe stanidard. The comprehensive index is 2.32. being scriously polluted. It can also be scen from Table --54, influenced bv the three tributaries. the indcx of COD. BOD.. NI L;-N, coli. Hg and petroletim at their inilcts into the Yongiiang Rivcr all excecd thte standard. mvith comprilehensive index respectively at 2.19, 2.40. and 0 6 1. respectivcly being scriously polluted. seriously polluted. and lightly pollutcd. 33 Table 3-5-3 Results of water quality monitored River item SS CODCr BOD, NH-N NO-N NO-N Hg pigL As oil coli Chaovang Average 71 211 87 21 S5 010 0046 2.56 0007 3 00 5 87xlO Strean ratio' 33 100 67 100 0 0 100 0 67 100 Erkeng Average 68 156 77 6.595 008 0022 0.22 0.009 5 2. 2IO Streani ratio 0 100 100 67 0 0 67 0 100 300 Zhupaichong Average 130 150 3s 8.643 0.38 0.032 0.05 0.011 2O 8.OxI0 Stream ratio. 50 100 83 100 0 0 147 0 300 100 Outlet of Avcrage 42 4.73 5 0 ss4 0.36 0.030 0.03 0.004 13 s. lx1.0 Chaovang ratio* O 0 67 100 0 0 0 0 100 300 Outkt of Average 22.3 5.2 43 0.76 0.54 0.030 0.003 0.006 1.4 8.3xlO Erkeng ratio' 0 33 67 100 0 0 0 0 300 300 Outlit of Avcrage 55 3.5 1 0 0o179 0.64 0.025 0.001 0.009 0.13 S. I x10 Zhupaichong ratio' 0 0 67 0 0 0 0 0 33 300 Se:tion of Avcrage 33 2.4 I.2 0 tS4 0,65 0.028 0.001 0.004 0 02 2.0xlO Sasuq ao ratio. 0 0 00 o0 0 0 0 0 Setion of Average 26 2.7 3I5 0o -O 0.60 0.032 0.001 0005 0 02 2 4xlO Slituuangjaang ratio' 0 0 67 0 0 0 0 0 0 Note ratio I is ratio ol exceeding standard Table 3-54 Pollution Index .rcam Ss C(I)-, HO()D, Ntl1- N0(-N %() -N fig A phenol oil I 'r1de'x ]kllutiol Ns utg!!. . . I degree Clijoyatu )J7 S4 3109 437 0 OOJ 0050 2 56 00 7 0.31 30 48 J I E rkeng (1 45 6.2 9 6 332 000 0020 220 0.09 0.10 52 22 6 I /hupai 08 7 60 f 4 117.3 0.007 003o 0 50 0.11 0.20 2.3 2. 1 Outket of 0 2X 0.79 3.2 3.8 0.02 (1 20 ( 30 0.08 020 2.6 2.19 I Cls"!aovan _______ ut1te:t 1f 0X 0X7 1.1 3.4 (1.0I (o20 0 to 0.12 0.20 2.8 240 3 Erkeng I_I_I luikltof (1.37 0.58 2.X 0.4 0.03 00 0 10 0.18 0.20 2 6 0 61 ScLtiosi ol tl22 (040 0.55 0.37 0.03 (.19 0 10 0.08 0o21 040 028 3 Salnitao I__I I__II_ Secmonol 0 17 0.45 0.25 0.54 0.03 0.21 (10 0 10 0.2tJ 0 4 0.30 -3 Shllitasig _ I Senously polluted 2. light polluted 3 fairly clean .34 3.5.2 Atmospheric environmental qtialitv I .Background situation of atmospheric environment This assessment makes use of the results monitored at four points in Nanning City in 1991-1994 for the analysis on cxisting atmospheric environmental quality of Nanning. The results reflect the background values of the atmospheric environment of the planned project. (I). Analvsis on the results monitored A. SO0 Table 3-5-5 Average Daily Value of S02 Monitored over Nanning, 1991-94 3 unit: mg/Nm Y'ear Qingshan M1unicipal Bcihu Qu Agricultural No. 2 Radio Average of Monitoring Station Sclool Factory the City 1991 0.016 0.040 0.024 0.036 0.057 0.039 1992 0.023 0.093 0.057 0.036 0 i 10 0.074 1993 0.023 0.090 0.079 0.054 0.08 0.078 1994 0.024 0.056 0.057 0.050 0 0oo 0.066 Ave 0.022 0.070 0.054 0.044 0 089 0.064 The table shows that the average daily value of SO2 of the four vcars is 0.064mg/Nm3. a little over the standard for Grade 11 atmosphere set by the state. It showed a tendencv of increasing in 1992-93. being respectively 0.074mgtNm-' and 0.078mg/Nm3. 0.23 and 0.30 times over the standard. The average concentration over the years is t hc highest at the point at No.2 Radio Factor, being as high as 0.089mg/Nm3, followed by that at the Municipal Monitoring Station, being 0.070mg/Nm3. also over the standard for Grade II atmosphere. As tile amount of SO, will increase along with the development of the city's construction and uidustry and the increase of coisumilptioni of coal. it is estimated that thic concentration of SO, in the atmosphiere will continue to exceed the standard. B. TSP Table 3-5-6 Avcrage Daily Value of TSP Monitored over Nanning, 1991-94 unit: mg/Nmn Yca.r Qingshall *, lliictipl Monitoring lkcihu Qui Agrciultural Ni, 2 Raidio Avcragc or St;zt on School Fiactorv thc City 1991 0.1(1 0 128 0.358 (t.51 0 23. 0 219 1992 00ox2 0 126 0.209 0.121 0241 0 174 l99, 0(.95 0.242 0.274 0, 168 ( 154 0.210 1994 (1J.A)4 0.211 0.232 0 17(0 0 IX6 0 200 .\sc. 0.096 10.177 0.268 0 15. (205 0201 35 The table shows that the average value of TSP of the urban areas over the four vears is 0.201mg/Nm', within the standard for Grade 11 atmosphere, but exceeding the standard for cities in the south of China set by the state (0.2mg/Nm3). It wvas the highest in 1991, at 0.21mg/Nm3. Of the points monitored, the average value at Beihu is the highest, being 0.268mg/Nm3, followed by that at No.2 Radio Factory, at 0.205mg/Nm3. C. NOx Table 3-5-7 Average Daily Value of NOx Monitored over Nanning, 1991-94 unit: mg/Nm' Y car Qingshan %tunicipal Llcihu Qu Agncultural No. 2 Radio Average of .__onitonng Station School Fadon. the City 1991 0.007 0.10 0.012 0.008 0.017 0.012 1992 0.006 0.011 0.009 0.006 0.019 0.011 1993 0.006 0.011 0.011 0.007 0.008 0.009 1994 0.006 0.008 0.007 0.007 0.009 0.008 Ac 0.006 0.10 0.009 0.007 0.013 _ The daily average concentration of NOx of the atmosphere fluctuated between 0.008 and 0.012mg/Nm3. with not much variancc and shoxving fairly light pollution. but within the standard for Grade I atmospherc. So are the values monitored at all the points. 2. Assessment of the atmospheric environrment Comprehensive index method is uscd in the assessmenit. Table 3-5-8 shows the avcrage pollution load of TSP ranks thc highest. at 58.99%, followed by SO. at 32.02%. that of NOx being thc smallest, at 8.99%. So it can bc seen that TSP and SO0 are the major pollutants affecting thc city of Nanning. Table 3-5-8 Comprehensive Index Assessment of the Atmospheric _____________ Environmental Quality of Nanning 11cI _ 1991 1992 1993 1994 Load Ratio SO2) Daily Avrage (0.032 0.074 0 078 0 066 _ pi n 21 0.49 0 52 0.44 I:i (1 198 0.445 0 397 0.295 32.02% TSI' DIaily Avcragc 0 219 0.174 0,210 200 Pli 0730.58070067_ 7. n jX() 71 fi7 ( 69 (.)527 0 588 0 619 59 98% No\ D)ailv Average - (1(112 (01 1 (419) 0 00g _ l'i 0l I1_ (1. 11 009 00') ___ 12 0 |113 0. 11() 0.0611 (0C86 ,9./9 __________ l'i I 06 1.IX 131 115 _06_ _ I ;l II _1 36 2. Assessment of atmospheric environmental qualitv According to the assessment outline, the items monitored are TSP and bad smell. 5 monitoring points wvere selected, at which samples were taken for three days i.n succession. (1). TSP Results monitored arc summed up in Table 3-5-9. It showvs that the TSP is from 0.05 to 0.58mg/m'. except the 2-. other stations arc exceeded standard for Grade 11 atmosphere. The 3 point monitored is the highest, maximum times is 0.93. Table 3-5-9 Monitored Atmospheric TSP unit: mg/Nm3 N Location of 3-day Range Number Number of Standard Maximum o. Monitonng Average of Standard Exceeding Times Samplcs Exceeding °e I = Monitonig St3tzion 0.1B 0.05-0.36 12 2 1 7 0.2 2 Bureau of lindustrv and 0.15 0.06-0.22 12 0 0 Conirnen:c 3 Prefecturc Bureau of' 0.24 0.10-0 58 1 2 2 1 0.93 Agriculture: I__ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ 4_ Chengbei Branic of U 21 0.09-0 49 12 2 17 0.63 Public Secuntv Bureau _ 5 Traflic Police 0 16 0.05-0 44 12 I 8 0.46 _ Ieadqunrtrs (2) Foul smell Thc Chaoyang Strcamii has had foul smiels for a long timc. MIonitored rcsults arc listed in Tablc 3-5- 1 0 Table 3-5-10 Foul Smell Monitored over the Chaoyang Stream Location Statc of foul smiecll Wk'alking Tractor factory Normal Xiuxiang Road Bridge Hydrogen sulfidc can bc smlclcd Ini from the river Prefecturc Hospital Hydrogen sulfidc can bc sncllcd 20m from the river Nanmian Bridgc Hydrogen sulfide can bc smcllcd 20m fronm the river Y-ouai Bridgc Hydrogen sulfide can bc smcllcd 30ni from the river J. .. 3 Noise e'nvlronntalc7J quahit 1. Background nolis cnvironmicintal situation (I). Noise pollution at function districts The Citv noisc sources arc various, incitiding thosc of daily life. traffic. industn- and 37 construction. See Table 3-5- I I for the results monitored ov er the noise in a 24-hour succession in functional regions in Nanning from 1989 to 1994.. It shows noise pollution in the functional regions of the city of Nanning has been increasing from 1989 to 1993. Table 3-11 Noise Level Nionitored in 24-hour Succession in Nanning unit: dB(A Year -Month Special lining Inhabitant Type I Type If Industrial Along the road quarten cultural niixed area mixed area quarters quanrc Ld dL Ld La La Ln Ld La Ld Ln Ld Lnl Ld. Ln: 1989 Jan. 49.1 43.8 56.7 48.7 59 7 51 1 56 8 48.1 61.5 55 8 70 1 64 4 65.8 61 2 1990 54.2 49.8 54.2 46.6 57.9 48.4 59.5 53.9 61.0 548 684 61 4 63.2 58 1 1991 to 54.0 48.1 52.4 44 1 60 3 51.5 59.8 48.6 60.0 54.1 71 5 67 1 69.2 63.9 1992 50.6 44.5 51.6 43 4 61.0 47.9 60.5 48.6 62.2 53.0 69 S 62.8 71.7 64 1 1993 Mar. 47.0 43.2 51.6 40.7 604 54 1 57 1 51.0 59.8 52.2 744 670 70.9 60.8 1989 Apr. 56.3 54.0 54.0 51.6 56.4 52.5 57.1 52.4 59.1 55.1 6-4 579 62.2 56.8 1990 48.5 45.3 52.2 48.9 59.4 45.4 57 8 51.1 61.1 546 7 ) 63 6 63.6 574 1991 to 53.4 48.4 54.5 51.0 58 4 429 57 8 50.8 59.3 520 69 *: 65 1 69.7 59 2 1992 52.1 48.0 50.9 43.4 59.9 46.1 567 45.3 62.6 584 69 8 54 0 71.9 68 9 1993 Jttn. 50.9 43 8 52 5 48 4 61.3 47.8 65 1 53.6 59.6 52 0 6S I 59 6 68f X 65 0 1989 Jul. 58.1 55.3 55 6 52.4 62.0 55.0 62.3 56.4 60.3 54 0 69 9 64 0 66.1 59 8 1990 50.2 47 1 501 45.5 56 500 57.9 623 58.3 53 . 5 5 64 6 5S 1991 to 4J9 417 558 506 564 442 614 53.9 548 50 6 6S: 645 674 601 1992 49.1 43 3 48 7 19 5 56 6 42 3 64 1 47.4 57.6 51 Q 6')s 64 5 71.4 66 8 1993 S. 558 545 594 510 549 50t6 92 53.1 5584 529 640 fi91 658 19S'9 (Ot 52.3 55.3 55 6 500 5O 0 4S 1 61 5 54.1 60.3 52 5 9 61* h 64.6 590 1991) 518 46.4 56.0 453 599 471 627 50.8 61.9 555 ' 1 649 676 601 1991 tli 49.6 42.6 51 4 425 6i 9 44 9 57 9 47.3 62.1 t15 __ 71 0 72.0 64 4 1992 52.4 450 52 1 40 1 61 5 466 61 9 48.1 60.8 5 I t 6i 0 734 650 1991 Nov. 53.4 45 9 54 9 47.0 60 6 58 9 56 7 44.8 64.8 578 6S ' I 614 69.3 6i6 6 19X9 wihoh: 53.3 50 5 54 8 50 7 590 517 59 4 52.8 60.3 54'4 (S 1 62 ( 647 592 199(1 % ar 51 2 47 1 5 1 46.6 5 3 47 7 59 5 52.0 60.6 54 6 *-N N 6fi I 64 X R 5 1991 51.5 452 540 470 59'2 459 592 50.2 59.0 526 -I - 66.9 69.6 61.9 1992 51.0 45 2 50 8 41 59 45 7 60 X 46.8 60.X 53 6:1 72.1 662 1993 51 46 54 46 X 59 3 52- 5-5 50.6 60.6 51 . 1) 695 64 6 (2) Traffic noise pollution From Tablc 3-5-12 it can be senCI that the averagc flowv of ehicles in Naniiing in 1994 3S increased 111.28% than that of 1991. The avcrage traffic noise in the roads in 1994 reached 74. IdB(A). \vith an increasc of 4. IdB(A) over that of the previous year. Table 3-5-12 Comprehensive Statistics of Traffic Noise along Trunk Lines of Traffic unit: dB(A) Average road Average load Weilghted average Average car Year lentllh (kil) \vidth (in) tralfic noise Leq [lo [.50 L90 flow ()er hour) 1989 54.17 29 70.5 72 8 67.0 61 5 599 1990 54.17 30 71.4 74 1 67.4 61 9 544 1991 54.18 30 72.3 74 8 68.5 62 9 665 1992 61.93 30 70.9 73? 67.0 61.4 774 1993 62.0 30 70.0 72.4 67.6 63 .5 10(8 1994 62.0 30 74.1 _ ?56 69.4 64 5 1405 3 Monitoring and assessment of the existing noisc environment lic assessment used the grid points method with key points at highly sensitive area and road crosscs. Altogether 21 monitoring points were chosen Timc monitored were May 29 to 31. 199'. at 7:00 - 18:00 hours during daytime and at 22 00 to 6:00 hours at night See Fig 3- 5- 13 for their averagc value of noise level. bjill TThe average value of cquivalcnt noise 1 600 level monitorcd duritig day timc is 58 9dB(A). 14z)0(1 / falling within the standard for Type 11 area 1o00 set in "Urban Arca Environmental Noise 80 - Standard". that at night is 55 4dB(A). 4(1(1 exceeding the standard by 5 4dB(A) Of all 2( ) the values miolnitorcd during the threc days. (i ''29 excecd the standard during day tUieC. wvith 1989 1990 1991 1992 1993 1994 a standard excecding MtC of 46 03%: 50 values nionitored at exceed the standard with Fi. 3-5 Average Car flow in N'anning a standard excceding rate of 80 6i5`%o The average value at 10 points cxcccd the standard durinig daytimic. accountinig for 47.62%/4 of all tile points. IX excecd the standard at nighit. accoulitinig for 85.71 % It can thus be seen that noilsC pollution is very scrious in thc arcas assessed. cspccially at nighit. Of all the monitorinig points. thc equivalent noisc Ievcl at points No. 12, No.3. and No 14 arc the highicst both during day timie and at nighit. P'oint No 1 2 is located indtie juncture of' busy traffic. while points No.3 and No 14 havc more complicated noise sources as thev arc locatcd in downtonvii areas, where noisc comes from traffic. constmiction, peopie's life aild othcr 39 sources. Point No. 18 is geographically remote wvithout anv strong noise source nearbv, thus monitored noise level there is comparativelv loxv Table 3-5-13 Average Value of Noise Level Monitored unit: dB(A) No. Monitonng Time Average No. Monitoring Location Time Average Location Value Value Monitored _Nonitored I = No. I Professional Day Timle 53.6 12 Entrance to Da% Tmne 72.1 I ligh School Night 50.6 Beihunan Road Night 63.6 2 Bureau of Industry Day Time 52.7 13 - Hospital for Woman DJ! Time 53.7 atd Convierce Night 52.5 and Children Night 49.7 3 Red Cross Day Tinie 65.5 14 Xiaojinshan D7ty Tinme 65.0 Hospital Nighit 63.7 Night 64.1 4 No.9 Hfigh S-hool Day Time 61.7 15 District People's Da% Timne 58.7 Night 58.3 Congress Ntpht 57.0 5 No. 13 Higih Day Time 59 S 16 Municipal People's DJ! Time 55.8 Sciool Nighlt 50.7 Congress Nitcht 49.9 6 No.28 High Day Time 54.2 17' No. I Hospital attached to DJ!% Timc 57.9 College of Traditional SciJool Night 50.7 Chinese Wedicinc Night 56.4 7 Nationality Day Tinie 61.6 IS Langdong Da% Time 35 1 Ilosputal Niglht 57 7 Nieitt 44.5 t IkithU inlabitant Dav lime 63 4 Pulmpl statioll D, Tame 63.2 quancrs NlgJlt 54 Nlght 63.3 .) Suburbs Diy Time 58 0 '0 JiaiItiaI l)istrnt Da.% Tiliw 60 S Go.enumelit Night 51.- Goovernment \aeht 55 1 I () Nnauig I)DaI -stime 63.' 21 I Nanuiing Ticatcr Dx. Timc 53.5 Prefeettirc Panw ConumitteC Nilt 544 Nadit 54.5 II Jiannming i hospital i)a 'rTime 63.4 Average of Da! 'ITime 5S.9 _ _________________ Night 60 9 all the powt.s \idt 55.4 3 5.4 .Solid waste matiers I. Background situation of solid waste in Nanning Solid waste mattcrs in Nanninig mainly consist of industrial solid waste matters. daily life garbage, and constructioni rcfLtsc. Thc total inidustrial solid waste matter produccd in Nanning in 1994 was 558 goot. The rate of comprehensive utilization overceded 77O. In 1994 the citv transported away 244 X)Ot of domcstic garbage. whosc rate of trcating %%as vcn low, thus 40) causing much pollution to the surrounding environment and ground wvatcr.. 2. Monitoring and assessment of the sediment the Chaoyang Stream. Sec Table 3-5-14 for the results of the monitoring over the bottom clay of the Chaovang Stream. Table 3-5-14 Bottom Clay of the Chaoyang Stream as Monitored unit: mg/kg Monitoring Point AS fHg Zn Cu Cr O)l Iac.r(0o) RI Walking Tractor factory 2 10 0.28 2987 6086 161 663 7 2S 417 Coliegc ofChiniese Medicine 42.4 2.75 748 202 241 5248 6 00 4S8 Naiumian Bndge 40. 2.77 3955 94.5 284 2503 4.68 504 Youai Bridge 60.8 2.73 745 169 213 5769 407 494.9 Dakengkou 27.6 2.63 594 83.8 163 3711 1 S0 450 The Hakanson index method was adopted in the assessing the potential ecological hiarmfulness of heavy mctals in the bottom clav. (For details. please see the assessment of environmental influence of the construction period.) Results of anaklsis find out the fivc RI values are all above 400, extremeln harmful to ecology. The water body' will also be senously polluted through wvater exchange. This deserves serious attention. Great care must be taken wvhen using thc bottom clay as fertilizcrs for farm field and forests. 41 4. Predicted Environmental Impact and Controlling Measures 4.1 Recognition of environmental affecting factors and screening of factors to be assessed 4. 1. 1 Purpose Factors affecting the environment at different stages and their degree were studied according to the characteristics of the construction to be undertaken for the project of' comprehensive treatment of the Chaoyang Stream, and major environrmental problems which might appear during the construction and operation of the project were screened out to be used as basis for key assessments. 4.1.2 Methods of screening The matrix method was used in the screening. 4. 1.3 Resul of screening The rcsult of recognition of environmental affecting factors and screening of factors of the proicct of comprehensivc treatment of the Chaovang Stream are listed in Tables 4-1- I and 4- 2.2.. those for the laving of drainage pipeline are listed in Tabics 4-1-3 and 4-1-4. .llajor cnvironniental problcms and affecting factors of the project of the treatment the Chaovang Stream (I) Raised dust and noisc during construction affect the atmospheric quality and people's life Cleaning away of the mud from the rivcr bed might causc secondary pollution. (2) The impact of thc projcct is mainly positive when the projcct is complcted and put into operation. while the ncgativc impact is local. as the sludge discharged by the water treating plant might causc secondary pollution. 2. Major cmvironmcntal problems and affecting factors of the project of watcr sc\\-rs and conduits (A) Raiscd dust and noise during construction affcct thc atmospheric qualitv and people's life, while the impacts is the mainly negative ori city traffic and inconvenience pcople's hLf (B) TleC impact of the projcct is mainly positivc whcn the projcct is complctcd and put into operation, while thc sicgativc impact is local. Pollutant from urban non-point sources and water discharged by thc water treating plant might affect the quality of the rccciving watcr bodics But thc impact on Lakc NanhU is long term and irreversible. 4.2 Analysis on the characteristics of environmental impact See Table 4-2-1 for tihc positive and negative. long term and short term. reversible and 42 Aesthetic aid tourism 7 0: - - - - ___ - U Culture heritage _ Recreatiorl 7 7 1 4 C _ _ c Livirw standard 7 _ . - _ _~ ~ iealth and sak'est -k _ > 7 AY _ Social econom__ e _ Transportation 7 7 _ Water supply quality _ _ _ Agriculture - dCtvopnient Industry development . t Land use 7 7 7 7 J i Forest vegetation _- _. __ - .t Aquatic ecology_ _ y Cit% land scape 7 7 7 F a irnmland ecololy - _ _ C2, __ __ ___ - - _ _ - - - U rhban ecoiog 7 o Noise entvironnient 7 7 - _ Atotiosphere quality 7 - _ S Surfice water qluihlit = v Surface water = ,; hydroloEy ___________ _ GCrouind wvater quality _ Ground water '3 hy drology -r~~~~~~~~~~~~~~~~~~~~~~~~~~L L "a-a -E -s - C L 43 lTable 4-1-2 Affecting factors in theChaoyang Stream environmental comprehensive treating project (during operation) Natural reso!i;cL s =cog = cii rc9ourc%. = Socaial en irolmnleiit I.il qu lit = __,_ '_ 'lCo USiVis *teltotll&tielll _~~ ~ ~ ~~~~~~ _ _ -~;; SI.eIt,I *-. *.m; -,1 L |S I 12 1'1: .l I X C 4. -4 - . - - - - C c. : 2 _ _ ISpludg dislwm_ * I 2 2 _ I 2 I 2 _ 20 Cic ligratra io _ 2 1 I t 2 . 1 _ I + I + I Q I apilig sietitl _* Sludgedispoal C.1 - .2- - Coli:ltisior} I1 .9 +6 ,13 ,4 = = +1 ,0 +4 = +3 +3 = 2 :2~ +1 +4 8 +5 = 9_ *33 17 * 12 +46 _ 10 Notc J--scrivus unipact, 2-- mcidititit imlpalmt I--lighlt imipact "- vilcllpC,""Ilegatisve ililpacI 'I'able 4-1-3 Affecting fncto s in Nianning CitySevage constr uction project (during construction) Nitural resodures _ .c resl i trces ocsocial enviroumenI _ _ khb (Ialitv Conclusion I'r. e.ts- .%. aI -2 * Sels agcd -oiut _ ' _... _ _~ . _ _ 1: - -~ dloramnlg sstm:n*l {1118.1.1 _ 0 ,.. * _ ~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q. Projectsov'W taller .2- 1 r .2 . 12 . Sc%.is t,,dg.c,,isdti lIls't Proecs ill' SC%% ageIItillt -2 r *2 I 31 - I 2 . I 21 .12 I2 2II . _ _ _ I -2 - 4…- - - - - - - -7 -6 *( _ 4 *9 6 -7 -4 7 -16 2 .12 -16 -12 .56 Table 4-1-4 Affectitig factors itt Nanninig City Sewage concturction project roject (during operatioll) Stage ttl' VI ~~~ ~L >¶ - >-> ne- - - - - ~ LIatural resourc"s i:.eological tsrotwI -S Soeial em irolunem Lile qualilx6 2 o.) l C. U6 a0. ,'.~ 6 . . -. . 0. C. .- - I ~ 0 C CL I'rvjecls ol-\V.tef *I 2 2 .12 I*2 1 1.I .2 t2 t 2 * I t 2 27/5 Se%w.rs I I . _ _ _ 2 Proje,ts otS ge *I *2 -2 *3 *I*2 2 I 62 + 1 42 I + I + I 42 o25 Pipelilles~~~I- _ _ _ _. _- _ __ F Proje.:ts ol n1aidificationl of'* I 2 . * .1 I 2 * .1 . I * 2 -2 + 2 + I *I .2 .2 5 JxJuliage s.Nstem ml old adjull; ram k -.tier itiltos mind Checkinig %%elb _ desi0ling anJi mialliltetallce +2 * 2 2 *2 1 + 1 +2 +2 +I +I t I t17 ofpipeliflc I I - I LI -- ' LIL subtotal -4 +'12 3 = *6 = 12 _ = .2 = t +G_= t8. -17 .2 4 16 .6.-2 PWJ~L1SOII~~iI~ -I -2 -2 .3 -I -2 1 7-2 'I '2 'I '2 'I 'I 'I +2 '25 irreversible, local and extensiv e impacts of the Chaoyang Stream comprehensive treatment project. Unfavorable impacts are basically during the construction period, of short temi and reversible, while favorable impacts are basically during its operation. extensive and of long tem So after the project is put into operation, its major impact is favorable. Table 4-2-1 Affectinig factors in the Cliaoyang Stream environmental comprehensive treating project (during construction) Negative impact Positive impact short long revemiv irrever- local wide short long wide local tenm tesut e sive t.rm term _ Surfice watLer hvdrologs s Surface water qualitv s Natural Ground waier hydrologv s =. = resources Ground water qcuaitv | s ' s_ Atimiosphere quality .' Noise environmentit Urban ecology Frramllarid ecology Eology Cityv landscape |. Resources Aqluatic ccology .______ Fores- %cgetatioui ILa.nd use Inidustry de.veelopriit Soc.:,aI A\Lrilittitrc &e%vioplitit ____ cl:\ Ir 1ruentmei Water sttppl!. qu1111\lX l'ransportatlon social eccgonoivy I Icalth and safest s _ , living standard s _ Recreatio' s qiuzalax Cuitire ltt ritagc = Acsthetic and iourisimn == Note 'sliort-tenil--relirs to the period of constrcltion *oiong-tenii--reklrs to lt:e period ot operaittioi 4-7 4.3 Prediction on the project's environmental effect during its construction 4.3. 1 Prediction on the project's environmental effect dzuring its constnrction of the project of (haotvang .Stream renovation A the construction of the project wvill last quite a long time and a number of construction machines and vehicles for transportation wvill bc used. plus the large quantity of polluted bottom clav. earth to be back filled and cast away as wcll as temporarily piled up construction; materials. problems like construction noise. raised dust, foul smell, secondary pollution. traffic blockage. and interruption of ecosvstem and city landscape will have negative impact on the environment and cause much inconvenience to people's life and the environmnent. 1. Analvsis on the environmental impact of the dredoing of sediment on the river bottom It is estimated that about 200,000m3 of sediment has to be dug up during the construction of the project, of which large quantities of pollutants will accumulate. Thus the cleaning away. transportation and disposal of the bottom clay will have certain impact on the environment. 1 PhMsical and chemical properties of sediment and major pollutants it contained Besides natural causcs such as %,ind. prccipitation and falling dust, the serious deposit in thc Chaoyang Stream is mainly caused by artificial factors like the deposit of suspcnded stibstances from industrial waste watcr and se%vage. and garbage from industrics. construction. municipal engineering and daily lifc. Large quantitics of brokcn bricks. glass. plastic. tree leaves, bamboo bits werc found in the sampics of sediment taken from the river bed. Organic matters contained in it includc deposited night soil not vet decomposed. castaways from the kitclen and industrial organic castaways. inorganic sedimiients from industrial waste water. There is also products from thc decomposition of aquatic organisms and inorganic salts from %%astc water. In a wvord, the composition of scdiment is vcr\ complicated. (I) Organic contcnt in the sedimcnt of the Chaoyang Streamtl Table 4-3-1 lists the organic content of the fivc samnpics of bottom clay takeni from the upper. niddle and lower rcaches of the Chaoyang Stream. Table 4-3-1 Organic Content in the Sediment of the Chaoyang Stream S;anple Nutnbher t.ocation Organic Conteni 1%) I [tipper Walking Tractor Factni 11 .3 2 ColIcec olCFraditional Chiiiiese Miedicine 25.2 3 " NJmnnian Iridge 12.1/ 4_ Yotai L1ndae 136 5" Dakcinkou 6 5 (2)Contcnt of heavy metals. As. and mineral oil In sedimenit As thc Chaovang Stream has been receivine %%astc water from over a hundred factories. 48 largc quantitics of heavv metals, As. and mineral oil have entered the bottom clay through exchange with the river water. Table 4-3-2 lists the content of these monitored. Table 4-3-2 Content of Heavy Metals and Oil the Sediment of the Chaoyang Stream unit: mg/kg L.ocation As 12 Zo ; Cu Cr Oil Watcr(%) Walking Tractor 1Tactor. 21 02 8 2,987 6,086 161 663 7.28 College oC Chinese Medicine 42 4 2 75 748 202 241 5,24S 6 00 Naniniaii Bridge 40 8 2 77 3,955 94.5 284 2,503 I 4.68 Youai Bridge 60 S 2 73 745 169 213 5,769 4-07 Dakengkotu 27 6 2 63 594 83.8 163 3.711 1.80 (3) Analvsis of the potential ecological risk of heavy metals in the sediment A. Index of potential harmfulness to the ecosvstem caused by heavy metals deposits In order to give a quantitative analysis of such risk, the potential ecological risk index used by the Swedish National Environmental Protection Agency and Lars Hakanson of the Pusala watcr quality laborator-v was used in the study. B. Mcthod used for the calculation of potential harrmful index(RI value) a. The determination of singlc heavy mctal factor of contamination (Cif) Cif = Ci surfaccJC n C'f- pollution coefficieit of a certain hcavy metal C' surface - conceintratioln of that mietal measured at the surface of the sedimlent Cln- refereniceX. valuc needed for calculation b. The degrec of hicav metal contaminationi (Cd) Is thc suilm of 1ally heavy metial cocfficiciit.; ('ci = C c. The toxic responsc factor. or the Tfe valtic. can bc used to shov the toxic degrce of heavv metals and thc sensibilitv of the \\atcr body to heavy metal pollutioln d. Tnhc potential ecological risk factor of a certain hcav\ metal. or thc E14 valuc IS determined in the following way: Efe = Te -Ce c. Thc poteintial ecological riski idcx of many heavy metals In thi sedimieiit. or the RI valuc is dcteninieied in this a! rI-I I ' , 49) By summing up the above wve can get the following equation: RJ=ZEE,- E C T e C, I C,. C. The determination of the indexes used in the assessment a. Heavy metal concentration at the surface of scdinient Thc value used was the onc actuallv measured. b. Refcrence value used in calculation The highest background values of the earth bcfore the industnralization were used as the reference value for calculation. D Heavy metals assessed Toxic heavy metals Hg. As, Cu. Zn. and Cr were chosen in this asscssment. E. Toxic coefficients of heavv metals Heavv metal toxic coefficients provide information on heavy metals' harmfulness to human body and aquatic ecological system. The sequence is like this: water - sediment - organism -fish - human body. The problem can be discussed from manv angles. We mainly proceed from the "principic of clement abundance" and "element releasing intensity" raised bv Hakanson. That is to sav. the toxicity of a ccrtain heavv metal is related to its intensitv of release: the easier a metal releases. the morc toxic it is. Processmg of a series of data finds out the order of the toxicitv of the above five mctals is: Hg > As > Cu .> Cr > Zn. Standard processing of their toxic cocfficicnts determnines their value as respectively Hg = 40. As = 10. Cu = 5. Cr = 2. Zn:= I. See tables for the Te- value calculatcd from thesc figures. Table 4-3-3 Maximum Background Values of lHeavy Mietals before Industrialization Ullit=ppm Ct _ _ _ __C_r .As Ilg __________________ j 175 90 j 5 ( 25 _________________ Table 4-3-4 Potential Ecological Risk Factor Ciu 7.ii Cr A _s _ _ _ I 1 ' . 1() 40 F. The division bcetwccn the harmfulncss to ecological system of hcavy metals in sediment. ccological risk index. and degree of contaminiationi and thc relation between ccological risk index Ej' E! < 25 -light ccological risk 25 S Er <-C() --medium ccological risk 50 S Er' 380 --very serious ecological risk Table 4-3-5 Values Calculated against the Highest Background Values before Industrialization Ef' Sample L.ocation As |fg Cu Zn Cr RI Walking Tractor ihctor' 14.0 44.8 3 38 17 3 58 4i7 Collcee of Chinese Medicine 28.0 440 i1 2 4 27 5 36 488.8 Naiuian Bridge 27 2 443.2 5.25 22 6 6 32 504 YOLuli Bridge 40.5 436 94 4.26 4 74 494 9 D)akenrgkou 18.4 420 4 65 339 3 62 45() The folloving conclusion can be draw,n after assessing the potential ecological risk of heavv metals in the sediment bv using Hak-anson's methods Er' of As contained in samples taken from the five sampling points raniges 14-40. of which three are of medium nsk: the Er' of I Ig at four sampling points are all over 200. posing as very serious ecological fisk. The Ef of Cu is above 200 at one point. also posing as very serious ecological risk. Tle Ef' of Zn and Cr at all the points are less thani 25, posing no potential ecological risk. As for the RI of all the heavy mietals, the values found at all the five points are above 38() (scrious ecological risk) Tne bottom clay of the Chaoyang Streamil is seriously contamniated. major pollutants being Hg. As. and Cu. Simple treatnient for the landscape such as water supplement and coverng up without dredging cannot get rid of the large quantities of heav nietals contained in the sedinicit. which \\ill be reieased to pollute the water even no more heavy mctals are to be disciharged into the river. As the wvater in the region is acidic, heavy metals will be easily released into the water bodv of thle river to cause sccondary pollutioni. And flood will bring pollutants from its bottom cla\ of the Chaoyang Stream into thic Yongjiang Rivcr. polluting the latter Besides. organic matters rot easilv at high temiipcrature in summer. releasting large quLizntities of foul gasses. The fotul simell and flies and mosquitoes from it make people sufTer. *-o sUIli Up, there are the followving probiems: a. Large quantities of heavy metals and other pollutants are contained in the bottom clay of tihe upper. middle. and lowcr segments of the river bed. comparatively more seriois in the middle and lower reachies. b Suppleentinlg \%ater wvithout dredging cannot clean away the pollutants which w'ill SI release into the wvater body to cause secondanr pollution, even to the Yon_iiang River in the flood season- c. Special methods should be used in digging up, and disposing the bottom clay containing rich heavv metals and other pollutants. d. High organic content in the bottom can be used as fertilizer. II . Anal sis on the process of nrver bed dredging The purpose of dredging is to ect rid of the pollutants in the bottom clay so as to remove the internal pollution sources from within the water body. Consideration should be taken not only for the feasibility and economical rationalit% but also for meeting environmental demands. The length of the river bed to be dredged is about 8km. from the Nanning Heavy-duty machinenr Plant to Daklengkou. See Table 4-3-6 for details. Table 4-3-6 Dredging of the Rive Bed of the Chaoyang Stream Range of Dredging Stj2e Lcngt Investment Widtl Depthi Earthw, ork % b_ (in) (10 vuan) (ni) (ni) tnm ) Youai Bridile to Dakengkou 199 3.01 9.1 18 2 7 110.250 55% No.28 !fig2J Schlool to Youai Bride 1J9S 3.21 9.6 1 2 2 5 65.100 32% fleav-duw Machinery Pliant to 1999 2 13 3.0 8 15 25,560 13% No. 28 ligh Schlool _ Total X.3-1 21.7 2-) .910 100% As thc total lengtih to be dredged is 8km. the total carthwork to be dug amounts to 200.91 Oni'. and drcdging is cstimated to.be compicted in thrcc years from 1997 to 1999. Ill. Dredging methods Drcdging will bc donc after the river watcr is withdrawn. As the river bed of the Chaoyang Stream is fairl narrow and the quantity of its water is not very largc. pollution intcrccpting pipes will be built first and external w%ater sources cut tip. Reaming water will be pumpcd out and the dredging "ill be donc after the rivcr bed is lcft to bc air dried for somc time. Drcdging can be donc all the year round. B1ut as high temperature "%ill intensify. the volatilization of toxic gasscs and rain water will wvash avav the bottom clay piled temporarily to causc secondary pollution durine the rainy season, it is recommcnded to dredge the rivcr bed in the drn scason. As the carthwork to be dug is not very muci but the dredging sitc -will strctch a long distance throtigih densclv populated inhabitant quarters. the constniction unit has decided to carm out the dredging by both men and macihincs as machines cannot be used in manv parts ThIe whole job will last threc ycars. averaging only 2km/a. Though the progress will be slow in this wav, it will causc lcss distirbance to the pcopic living nearby as therc wvill bc less and shortcr noise from the machines. IV. Analhsis of the environmental impact during the dredging (I) Analysis on noisc pollutioni 52 Machines like excavators, bulldozers and transporting vehicles used in the process of drcdging xvill produce noises of high levels affecting surrounding environment, especially sound sensitive areas. Investigation found cxcavators, bulldozers and loading machines can produce noisc of 95dB(A), and the enginc starting of heavy trucks can producc noise of 95dB(A).The folloving formulas can bc used to calculatc th1e wveakening of these noise sourccs as the distance from thcm increases L. = LI -201g7 Iy -AL In %vhich: Yi. y:--- distance from noisc source, m LI. Li. -- noise level at the distance of yj. -'!. dB(A) A L -- influence of buildings. trees. etc. on noise, dB(A) Calculation finds out that for a noise source xith a level of 95dB(A). the noise level can stili reach 68dB(A) at the distance of 20m from it, 62dB(A) at 40n, 58dB(A) at 60m, 57dB(A) at 80m, and 54dB(A) at 100m. According to the standard for Type I area in the "Standard for Urban Area Environmental Noise Lcvel", that is inhabitant. cultural and educational quarters. noise level therc should be belowv 53dB(A) during day tLmc. for Type 11 area, that is inhabitant. cotmnmercial. and mixed industrial quarters, it should be below 6OdB(A). Noise sensitive places along thc Chaoyang Stream like thc Beihu inhabitant quarters. the Nationalitv Hospital. and the Guangxi College of Traditional Chinese Mcdicine will be affccted, and tihe noise level in tile inhabitanit and comniercial quarters in thc lowver reaches of Youai Bridge will exceed the standard by 2-5cdB(A). Accordtng to the planned progress of the dredging. it is estimated each noise sensitive point wvill bc affected for about 20-30 days (2) Anal\ysis of the Impact of temporarily piled sediment to the civironment If not transportcd away in timc tile sedimnctt piled along thc rivcr bank will produce foul smiell, fonr raised dust when aired dry and blownn by wvind. and bc washed to spread by rain water and causc secondary pollution to surrounding soil. xvater bodies, ground water and the atmosphere throughi soaking. secpinig. leachinig. and volatilization T-hus toxic substances and causative agents \ill spread through thc mcdium of watcr and the atm1osphere. Obscrvation has founid that thc surface of sedimiient containing 20% of water pilcd along the bank of thic river w\ill become dry in a few davs \tith a wind spced of 2 Sm/s. TSP in the raiscd dust from the scdiment pile can affect as far as 15O;im in thc leeward direction. Withill that rangc thc conccntrationi of TSP in the atmosphcrc may rcachi 490ugim3. about 1 .6 times of the standard for Grade It of environmental atmosplheric quality. Without rain. part of the 20%, of water containicd in thc bottom clay w%ill cvaporatc into the atmosphere, part w\ill soak through the bottom of the pilc to flow to lo'v lying places to spread its pollutants. In case 50% of the water soaks out. therc will bc altogether about 20000ii(0 of soakage. \%hich will contain 20.000nmg/l, of 30D5 and 30)000nmg/L of COD. forming a scrious secoridarv pollution source. lHeav rain Of storm wvill wash awvay all thc sedimcnt pilcd. thus causinig more serious secondary pollution. This equals shifling the polluted bottomil clay to thc ground surface to be disseminated to larger areas and it \vill be almost impossible to "gather it up" aeamn. j3 Sediment piled up along the river bank also affects the landscape of the city if not removed in timc. Investigation found out the foul smell it gives out can reach the 4th grade. (Intensitv of foul smell can be divided into 6 grades from grade 0 to grade 5: grade 3 gives out obvious foul smcll. grade 4 gives out strong foul smell: and grade 5 is extremelv foul.) producing veny unpleasant sensation. The foul smell is caused by substances like ammonia, hydrogen sulfide. volatile alcohol, aldchvdc, and acid produced in the anaerobic decomposition of organic matters contained in the bottom clav. V. Analvsis on the environmcntal impact during the transportation of bottom clay The following environmental impact w\ill be caused during the transportation of bottom clav: (I) Poor sealing during transportation or the bottom clay being too thin \ill cause droppings along the transpiration route to harm the environment. (2) Vehicles transporting bottom clay \ill add to the crowdness of traffic. It is reconunended that the following measures be taken in the transportation of bottom clav: a. Use well sealcd garbage vehicles or ordinary trucks lined with double weaved cloth and covercd with tarpaulin to prevent bottoni clay from dropping out; b. Directl) load the bottom clay dug up unto transportation vehicIes during machinc operation so as to reduce its chances to touch the ground at thc construction site: c. Statistics from road traffic noise monitoring found out: Normal vehiclc flowv of the area is about 1,00-3.000/h. Trucks with loadinig capacity of 4t ' ill be employed to transport the bottom clay for a total of 10 vehicle times/d singlc ways., and if countcd double wav, it mcanls 300 times. 4o times will hiappcn in cach of thc 8 working hours of a day. So it is estimatcd at least traffic flow will increase by 4% is Icss crowded roads. and about 1% in crowded roads. Thcrcforc it is rccommended to carrn out the transportation betorc and after nomial working hours so as to reduce tihc pressurc on traffic. VI. Utilization of bottom clay as a rcsource for forests and thc closing of piling ground (I) Fcasibilitt of using bottom clay for forcsts Tlic total amount of sediment of the Chaoyang Stream to bc piled is about 200,000m3. accordinig to the Municipal Environmental Moniitoring Station of Nanning. The Administration of the Chaoyang Stream holds that scdimcnt dug up can be used as fertilizcr for lawns and trees (but not for farm fields) and for hygiene land filling. The segment of thc Chaoyang Strcam from thc Heavv-duty Machinerv Plant to No.28 Higih School contains about 25.560m' of sludge. %--hich is only lightly polluted and can bc used as forcst fcrtilizer. Naining Medical Herbs Gardcn can provide 27ha of piling ground. the transportation distancc averagcs 5kIm (based on the intial plan of bottom clav disposal by Chaoyang Stream Administration). The scdimcnt of thc Chao-yang Strcam contains much organic matters uld manm trace cleniets besides the three :iiaini clements of contained in fertilizer: N. P. and K. It can be used as fcrtilizcr for forcsts to raise the soil's fertilitv and raise forestr) production. (2) Secondarv pollutioni in fertilizing forests and its preventive nieasures The shifting of chemical elements in soil is mainly carried by wvater. Washing and cluviation by rain water ,will move pollutants contained in the bottom clay through surface runoff and seepage, the former causing surface soil pollution along its wva and the latter carries pollutants into the subsoil. Organic matters and oxidizes of Fc. Al. and Mn will be fixed in the layer 20-30cm decp through absorption and complcxion. So proper amount of bottom clay used as fertilizer for forests wvill not damage thie soil or pollute ground wvater. The above analysis shows that the prevention of runoff pollution through rain water cluviation and washing is the key link of techniques required. It should be pointed out that the bottom clay transported to the botanical garden shiould be used in time, othervise it should be piled in a planned way, with lining below and cover above to prevent it from being washed away to pollute surface wvater or producing raised dust to pollute the atmosphere. 7. Sediment used for hygiene land filling and prediction on its environmental impact Sediment of the segment of the Chaoyang Stream from No.28 High School to Dakengkou cannot be used as fertilizer because in it much heavv metals have accumulated through deposit over a long timc. Its total amount is about 175.350m3. accounting for 87% of the total containcd in the sediment of the wholc of the Chaovang Stream. This amount is to be used for sanitarv landfill according to the original plan. The feasibilitv report compiled by Bcijing Municipal Engineering Institute suggests to open up a landfilling site in Yanziling, and the Chaovang Straum Administration suggests another location near Santang in the northeastern suburbs of'the city (Fig. 4-1) (I) General situation of Yanziling Yanziling is in the northeast of the constricted city of Nanning. It was turned into a inhabitant quartcrs in the latEc 80's. which nowl has 1.408l houseiholds wvith 5,342 people Adjoinilig the quartcrs arc thc ActE Ienc Factor-v. Carton B3ox Mill. Leathier Clicmical Factor\-. No.4 People's Hlospital. District Brancih of Electricity Desiginillg Institutc, Zhivaull Higil School. Police School. Nomial School of Nationalities, and thc 5th Division of No. I Assembiling Company of District Constnrction Corporation. Its surrounding areas arc undergoing furthcr constructionl According to thic overall plan of the city. both thc cast and %vcst sidcs arc the oIx direction for the city's furthcr spreading. Yanziling is a hilly place to the cast of Wuming Highway and to the northi of Nannifl'- Wuzhou H-lilhava". It consists of a hill wvith an eevation of I 18-I 32ni and thrce vallevs with an elcvation of about 25m. It is located in the drainage arca of the ZhilIpaichiong Strcam. The top of the hill is about 1.3i0m awia\ from the river. Thc flow directioni of rain gathered is mostl\ throughi densely populated quartcrs except the northi valley. \here thcrc are sparsc inhabitants Watcr of the north valley is directwk dischargcd into thc Zhptipaicliong Stream. and water fronm the west and soutil valleys flows inlto thc Naniliu Lake before it flows into the Zhtipaiclione Stream. In the \alleys are vast crop land anid pools, most of w%hichi are now used for agriculture Thlic top of the hill is mostly of cla% -- dcposit of thc Quaternarv Period. Thei top laver of the vallexs is of cultivatcd soil or silting clay. at about 2-3m deep. Belowv it is mostly weathered . N XC/ *1 i~f I S 1/ \S ;o } a ! 4~~~~ - \ S .. \: Ls7dong~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[ n : 7 - ' ii \je . 9 '/ er Fe~ ~ ~ ~ ~~~ - T 0 "I~~~~~~~I .- V -~~~~~~~~~~~~~~~~~~~~1 2!; . Chaoyang strcam comprchousivc trcatmcnt -t in RoadlnniT TStream ~~~~~~~~- / .1. - . . A O Location of filling ground site resettlement t th e,/ Chaoyang stream compIeheusive treatment pr ect i'n Nanning city niudclav and still below lies the rock laver. In somc localitics there is a laver of gravcl on top of mudclav. Ground water there is mostly stored in top layers. closclv related with surface water and the change of seasons. The highest ground water level is over 1.5 below the ground surface. The local people all use watcr supplied by the city's wvater supply network and nobody uscs ground water. The quartcr has already built its initial road ncr"ork and its infrastructure is already in shape and the quarters has a fairly sound administration system. Field investigation found no garbage disposing ground in the area and there is no plan to build one there. Considering thc fact that Yanzilng is within the 4km range of the dowrntown of Nanning City, it is not advisable to build a garbage disposing ground there. (2). Brief introduction to Santang A. Climatic and hydrological conditions of the filling ground arca Nanning City is located at the bank of the Yongjiang Rivcr in the olive-shaped flat Nanning Basin. its ground surface elevation at 7 1.67-75 .67m, surrounded by low hills with elevations from 200 to 500m. The average annual air tlmpcrature is 21 .6C, with an average precipitation of 1.300num/a. The overwhelming wind of the ycar is thie eastward wind, the average aniual wind speed being I.5-2.3mIs, with a maximum of 35.2m/s. Most part of the urban areas are of Gradc If tcrraces. inclining to the middle of the river with a gradient of about 0.07% and the clevation of the tcrrace surface beine 74-80m. 10-15m above normnal water level of the YongIang River. Thc terraccs arc fonried of alluvial matters: braided subclay in the upper layer. gray subsandy clay in thc middlc layer. and gravel in the under layer. wsith a total depthi of 25-30m and ground wvater is 6-1i6m decp. Within thc range of 0.5kim from thc Proposed filling ground is mostly familand groxineg maize and a few\ placcs have somc bushes. Thc ccntcr of the filling ground is lo%\ M iv surrouLided on three sidcs by small hills accessible by automobiles. B. Principles for the scicction of bottom clay burial uround The following principlcs should bc considered w%hen sclecting a burial ground to prevent sccondary pollution: a. In the leewav direction of the citv! b. In thc loNvcr reaclies of the city's watcr source. c. In the lower rcachcs of thc city's ground water. d. Far a%%a% from inhabitant quartcrs and scener\ spots. c. Meeting the demands of plans of the local government. f. Mlecting the demands of the design of the project g With convenient transpiration. and the road leading to it should be all weather road. Ii. Seepinig rate of the soil < 10-7cm/s, and i. The land is of fairlv reasonable price. Of course it is hard to find a place compictely sati-tvIng the above conditions, howcver. it is possibkl to select thc best place throughi comprchensi\ e analysis. vVhat follows is an analvsis over the conditions of Santang (Pleasc refer to the tablc of 57 strata of Nanning Citv and its surrounding areas.) First of all, a burial ground in Santang can meet above mentioned demands d. e. f. g. and i Although the soil there is of E3, mainly consisting of sand rock, aleurolite, muddy sand rockc. quartzose sand rock, and powvder-lined sandy mudstone, belonging to the structure of Oligocene Series of the Tertiarv System of the Neozoic Etathem. Though it has a fairly high seeping rate. it has little impact on ground water as it is far away from the urban areas of the city of Nanning. which basicallv relies on the Yongjiang Rive for its water supply (accounting for over 90%) The situation will remain so even till the vcar of 2010. Water sources on the Yongjiang River are all located in the upper reaches of the outlet of the Chaoyang Strearn. Even with a little entering the Yongjiang River through surface runoff. the water quality of the wvater sources on the Yongjiang River will not be affected. Though the overwhelming wind the year round is the east wind, what prevails in summer is mostly the southeast wind which will bear no influence to the citv. The northeast wind in winter vill affect the urban areas but the air temperature then is low and thus the influence is small. So as a whole, the burial ground in Santang can basicaliy meet all the demands. C. Possible environmental problems caused b' land filling The bunral of bottom clav mav have the following environmental problems because the bottom clay contains heavv metals: a. Soakagc from the buried bottom clay may causc local pollution to the ground vater nearb!; b. Foul smell produced by the bottom clay may affect pcople nearby: c. Soakage may affect surrounding familand: and d. Washing and eluviation of rain water may cause pollution through surface runoff. 2. Prediction and analysis on the environmental impact of Waste water intcrception pipeline network Thcrc is so far no ideal sewage system in Nanning City. The one existing is basically to reccive rain %zatcr and scewage together to be dircctly discharged into natural water bodics nearby and finally to 1owv into the Yongjians River. Thc city's sewage system covcrs an area of only 26knm. accountilig for only 38.2% of thc city's constructed area. (The average national rate is 54.29%). Tlc average pcr capita length of scwagc pipeline in Nanning is only 0 2 Im (\while tihc avcragc national ratc is O.5m). Waste water intercepting pipelincs built in the early 60's are no longer in good function So tlhis project bears great signilficancc not onl\ to the treatmcnt of thc Chaovang Strcam but also to the overall sewage system of the whole citV. i . Leigth and progress of the job The constructioni of waste water intercepting project plans to build sewage pipelines along both banks of thc Chaovang Strcam bclox\ Youai Bridge (thc ollC along the right bank \%ill join the one along the cflt bank aflcr recciving waste water from the Erkeng Stream). "hich then cross the Yongjiang Rivcr to join the trunk scewvagc pipelinc in Jiangbci District. A pumping station is to be built at the juncture of pipelines from the left and the right banks. Tnhc wholc construction is to be completed in 5 ycar sacording to the plan.. The total length of pipeline is 25.5knm. involving a construction area of 36.2km2. \with an engineering water dischargc capacity of 898.OOOm3/d in the rainy scason and 400.000m3/d in the drv season. Because the construction involves a v\ry long distance, lasting a long timc, and be carried out in urban arcas of the cit'v, and a large number of machines will be used, there will bc incvitably much impact on the environnment. 11 Possible cnvironmicnital problcms during the construction (I) Drilling macihines. excavators, loading machines, and transportation vchicies used for the w%astc wvater intercepting projcct will produce much noise at the level of 90-95dB(A). Calculation finds out that the noise level in the inhabitant, cultural and education quarters of Txpe I areas, and inhiabitant, commercial and mixed industrial quarters of Tvpe 11 areas will exceed the standard set in Document GB3096-93 "Environmental Noise Standard for Urban Areas" -- respectively being 55dB(A) and 6OdB(A) during day time -- when the noise produccd by the machines is added to the original background noise of those areas. (2) Most of the constructioni will adopt the method of underground pipe-jacking. As no large amount of refilling carth or construction garbage will be piled. therc will not be much raised dust in most part of the construction site except in thc segment down Youai Bndge. v,here the openl slot construction will produce certain amount of refilling earth and castawvay earth to be piled for 15-20 days. Wihen thcre is strong wind, tTIC concentration of raised dust can reacih 3mg/nii at Im in thc leewav direction. I .5ng/mr3 at 25ni. and 0.5 mg/n3 at 5On Thc concentratioin of TSP will exceed the standard at placcs within the rangc of 60m in the leeway direction (3) A total iumtiber of dozeins of thiousanids cubic metcrs of carth wdill have to be cast awav af'tcr the open slot construction. It can bc used for ground or road leveling. As the earth to be cast away is just local carth. its droppinlg during constructionl iXfll causc no other pollution except raised dust. (4) All the wastc wvatcr pipclines will bc laid at the sidcs of the existing road. Ther IS no nccessity to block traffic along the direction of the pipclines. But the piling of refilling earth and laxil n of the pipes w.ill occupy ccrtain part of the bicyclc lane and thc pavcmcnt. \}hcn a pipeline crosses a road. in most cascs a hole will bc dug under thc base of the road instead of opening up tihc road surface. But vehicles withi hcavy load have to bc prohibitcd to pass for a siort period Thcsc tw\o factors will havc some impact on traffic. especially in Mlngxiu Road. Henvang Road. Zhonghua Road, Youai Road. Chaovang Road. and Ninvang Road. which all ha%c busy vehicle flows. It is estimated that thc constructioni will affect each road for about 20 da\ s as is nceded b\ thc construction. About 1.0()( truckloads of building materials (dinas. cement. ctc ) and cast away earh will be transported for thc conistrction. But it wvill not bc very concentrated in time and wvill thus add ittle pressure to traffic. (5) Dians. concrete pipes. and casta%\a\ earth and so on piled along the roads of construction Site v ill af'fzct the landscape of the city and cause somile damage to the grecen land constructioii siEc \\Ill af'i'cct the laildscape of t,I and trees. causing some harm to the ecological environment 3 Prediction and analvsis on the environrnental impact during the construction of the wvaste water treating plant I No buildings need to be removed before the construction of the liangnan wvaste water treating plant and work can start after requisition of land needed. As the site is not located in dow-nto--n area, the machines and transportation vehicles wvill not cause much pressure on the traffic 1 . Therc are not manv inhabitants around the site of the planned plant. so there von't be much environmental impact. But there will be somc negative impact like raised dust from base digging and loading, unloading. piling and mixing of castaway earth, materials like dians. cement. and lime. and noise from construction machines and transportation vehicles. Raised dust mav affect areas within lOQm in its leewvard direction that the concentration of TSP %Idll exceed the standard- To reduce the impact, enclosing fence can be built around the site befoire construction started. 4. Prediction and analvsis of the environrmental impact of the laying of trunk pipcline in iiangbei area and the pipe line crossing the liver 1, Machines. cranes and transportation vehicles shall be employed during the construction of the trunk pipeline in Jianbei area and its attached engineering work, as ditches shall be dug along the banks of the Yongjiang River. So there will be somc noise affecting ncarbv areas where inhabitants, cultural and educational institutions concentrate and commercial areas mix with industrial areas. When such noise is added to the original noise. the total will exceed thc standard of 55dB(A) and 6OdB(A) set for typc I and typc It areas b! Documcnt GN3096-93 "Urbanu Environmcntal Noisc Standards". 11 Largc amount of cast awav earthwork- will bc produced as the trunk pipcline in Jihnagbci shall usc concrcte squarc pipes Such earth can be uscd for land road lcvcling. As the matcrial will bc transportcd by and bv. there won't bc much impact on traffic. Ill. As there will be ditch digging, pipe sinking and land backfilling during the process of sinking the siphon pipcs. navigation on thc river will be affcctcd for sevcral days. . Prediction and analysis of the impact of Chaoyang Strcam treating projcct on the city's ecological landscapc Tic construction of thc project involvcs a largc area in the city's sensitivc urban part. wlhcre several major streets will bc dug with a total length of about 25km, accounting for 10 O of thc cit-'s total road. At the samc time, the piling of construction garbagc. bottom clas. castawvav carth, and tilc temporary constniction huts and camps. storagc sheds will all affect thc city s landscape. 7he constniction will last two to three years. A certain number of lawnis and trecs will be damagcd to causc damage to the ecological system.. 6. Analysis of the environmental impact of building removal and inhabitants resetticmcnt i Scopc of removal hlc scope of removal involve 30-68m on both sides of the rivcr's central line for pipelinc 60 layling and riverbed wvidening. Sec Table 4-3-7 for the concrete scope of removal for construction and material piling. Table 4-3-7 Range of Buildings to be Removed along the Open Tunnel Construction Site No. Scmnenit of thie Chiaovaiig Stream Leingth(m) Removal Wk idth(tn) I lfeavx-duty Machinlerv Plant to No 28 HIgJi School 2130 30 2 No.28 Iligih School to Youai Und2e 3170 35 3 Youai Bridge to Dakengikou 2700 42-68 Houses to bc pulled down in thc range are mainIy simple ones of single or two stories. Some parts of the region border parallel small lanes and side streets. Only a few high-rising buildings %vill be affected bv the construction for short tenrs and their land will be retumed after the completion of the project. 11. The amount to bc pulled down and removed See Table 4-3-8 for details. Table 4-3-8 Statistics of Removal No. Items to be luilled Domi or Renioved Unit Quantit Buildings belonging to instItutions 1n2 81542 2 Inhabitanti houses i2 38052 i loTisehiolds to be deXmolished household 769 4 I 'Optlatioii to th re:moved people *I 0o6 L l.amiip and cabile posts 420 6 Trees 7 I'llllIc toilets . 8 ;Green lields in6 864)1 9 LI.and to be pernianentlY uLsed ha 3 5 In Laid to hc coiniiensated n' 1:535 ill. Policv for iniabitanit rescttimcent and compeinsationi standard Tnhc "Interimil Rules and Rcgulations for the Administration of I-lotise Removal in Naaniniiig City" was put ilto effect on November 3. 1(92 by thc Nanning Municipal Govcnimcnit. Thc nilcs provide details for houses to be pulled down. thc removal and resettlenient of inhabitanits and conccned complensations. As most of the hiouscs to be pulled down are in Types 1-2 regionis and the peopic will be resettlcd in Ty-pcs 3-4 places. thc standard for compensation for removal from Type I ro Ty pe 4 places is to bc carried out. No compensation xvill be made for public houses, and thc compensationi for privatc hiouses \%ill be carried out at the ratc of I Sm2 per houseihold Thc C, I following index wvill bc considered in a comprehensivc vav for land requisition: building density < 31%, net population density < 1.500/ha; average number of stories: 8: building volume rate: 3.8. [V. Analvsis of the environmental impact of inhabitant rescrtlemcnt (1). The environment of the area for resettling the inhabitants to be removed frorn construction sites. House to bc pulled down and removed involved in the project fall into four types: a.(Public and private) buildings; b. Public facilities like roads, public washrooms, lamp and communication posts; c. Trees and green fields; and d. Cultivated farmland to be requested. No rare or threatened species of wildlife or plants are found in the planned construction sites. There arc no cultural relics under key protection or quarters concentrated bv national minorities or religious communities. According to the overall plan of Nanning City, the inhabitants to be removed .%ill resettle in Xinvang Road quarters and Zhongyao Road quarters. (See Fig. 4-2 for the layouts.) Both quarters arc in the central part of downtow.n areas of the citxy with convenient traffic and there arc within easy reach schools. hospitals, shops and markets. Thc new inhabitant quarters arc already in good shape with overall planning for power and water supply. 769 households with 4 500 peoplc will resettle in the new quarters At the ratc of 1,500t/d, they will produce about 550 OOOt/a of waste water. wvhich will be discharged into the citv sewagc system after being treated in septic tanks. No additional pollution will bc caused to the Yongjiang Rivcr. Their domestic garbage will bc collected by sanitar- workecrs to be disposecl by the garbage trcating plant and so no major environmental impact -vill arisc in thc new qtiartcrs (2) Life qualitv of thEc iliabitants aftcr rcsetticmeit Most of the public buildings to bc pulled down are of brick sinicture and only a fcxv are of concretc structurc, and niost of the privatc houses to be pulled down are simple houses of brick anid wood structurc. Ve-, few of thcm have hygicnc facilities or se-,agc pipelines. nhc average per capita living spacc is onlv gil. In the new qiartcrs cach houschold will havc a suit of ncxvel built apartmcnt housc of brick-concrcte structurc vith wvater supply. kitchcns. hygienc facilities and sewvagc pipelincs. and the pcr capita living spacc will bc incrcased to 12mZ. So thcir living conditions will bc greatly improvcd as compared with that in the old houscs. And public facilities in thc quartcrs have becn built beforehand to give muchi convince to tihc new scttlcrs (3) Estimation of cost of the resettlcment The basic pricc for land in the new living quarters is 680 yuann!m. and tile compreihcnsive constriction pricc for nornial houses of brick and concrete mixed stnicturc is about 550 Yuan/mn2. Added with fecs for roads and w-atcr and ccctric po%\cr supply and tax, thc overall investiment for land rcquisition is at 2,908 vuan/m 2 Thic total cost for the rcmoval for thc project is calculated to be about 103 million yuan. (4) Public participation of tiic inilabitants to be removed 62 : t? \ , X .. X, , e~~~~~~\ \ \ / - ' 5I 0 0 -L ~~~~~~~~~~~~r S<\~~f At I. 4;' V d|gji \ I.!-I1 DadXIlg --D .'.-Ss .-......,.i j~~~~~~~~~~~~~~~~~~~ . ...... __..__._. N~~~~~~~~~~~~~~~ 4 >~~~~~~~~~~~~~~~~~~~~S I,l huaJci. ltnv il,,ng- x ,., ittiang,;, 'I.t & \.tih,U Jti-'nig p.un'g pIang g & MNIaduolle 19)t)4 )920 I11)I 627 1,J 65 1165 4 69 .343 Y8X2 A\mu1unt I.),)7 ') 61 12 54 6X 17 112 19 21 4 14 6172 (IoJ' 2000,w 11)25 1t52 784 1 1)q9 1,114 610 54 6 68(20 2011s 142 197 1I5 17 , I8 3 13 4 22 120 I)i.h:lrS 11(11 )I 1if4 161 150 I 4 1 S 4 17( ) 185 * rI C(M ItM. 7 4'HK (m1g 1 (01)) '¢)-1 401 S4(, 427 427 32S 41X T'able 4-4-7 Mlonthly CODM,n Load of the Catchment of Tributories of the Vongjiang River in Nanning 11"111ti I SItslbu R. I.Itil It KH , Idi . .iiv I.rkcL I);iD.mk Nnilm /.IuX idltmich ng Naiiall R hallgkol R. Pcnging It. Mach1do lki.111 Lillpichung Tol;gI I 52 2 114 6 09X 13 422 7.465 21 165 7 543 10 837 .161 37.78 4.00 4.613 .176 4.353 120.17 2 .403 1.542 4.448 9.791 5.445 15.438 5,502 7.759 .1172 7.55 2.984 3.365 .128 3.175 87.65 I o2 .11 )90 I 91 I 107 * 1-140 I I l 1 578 (12.1 5 (. (.07 684 026. .616 1 7 X I 4 008 .030 087 192 .107 303 .o0 IS2 .002 54 059 .066 .003 .062 1 72 5 765 292 8 449 IX 59 10 342 29 122 10 450 14.737 .223 52.33 5.667 6.391 243 6031 166 48 6 8 )96 3.2 K9X * 948 9 20 X90 1 16 175 129 31X 117 I94I 165.542 2.500 S87.89 63 65X 71 791 2 734 67 751 187o. 11 7 4 541 17 378 50.134 110 345 X1.369 173.997 62.013 87 446 1.320 310.55 33 627 37.923 1.444 35.789 987.X8 8 656 2 510 7242 15 9 .) X.X64 25.133 8957 12.631 .191 44.86 4.857 5.478 .200 5.170 142.69 9 219 .840 2.423 5.334 2966 8411 2998 4227 .064 15.01 1.625 1.833 .070 1.730 47.75 M( (81(1 00(1 000 /))1 .000 0o00 .000 000 .000 .000 .0o0 000 .0(0 .000 0( I! 459 1 756. 5 06p7 11 151 i6 202 17 5X84 X 267 8X 17 1.33 31 318 3 .398 .3 8.12 146 .1 617 99 8.1 12 I15 I 2 (1 1.17.1 7 647 *1 241 12 058 4297 6 060 091 21 52 2 330 2 628 1,(P 2 480 68.46 :1 ; 1I 59*7 6 I S15 121 215 4o1 29) 224 295 615 19 *U22r 649 I 1 ) 60(f. 4 826 1115 02 122 902 1_ 6I05 5278 1380 04 1610.57 4 . I Tahle 4-4-8 Monthly COD 1,, load of the Cateniiletit of Trihtitorics of thlc 'oY gijia.ng River in Nnniiing :til"l,il R Sliiul R 1.1,o ke.l R. K1l Rt X.\IN-Vv I,rkita ID)aLng li N;iiiIii AhN.IIidIpi N Ud IN hanio IjVlllialcigI I? Madla' I I Iwl. lcic'Ill" I .i.i3 1 2 5s7K 9*945 3(0731 67.004 39080 113078 43265 53 594 71 1759 91 21 135 22549 (019 244115 606i 17 2 I 9(9 7.370 22 773 49 6f52 21 960 83 79-4 32 6(1 .39 714 579 130 17 IS 662 16 709 755 IN 1.34 44X 45 1 42(0 i 623 5 016 30 935 6 378 11 .155 7 061 X 7.17 1 21 21 71 1 4149 16 6X 1I66 I996 1911' 77 4 046 .176 544 I 86 .691 2.(001 .765 941 0314 3 II .74 399 0ix 431 3071 5 .1511 13 556 41 887 91.328 53.267 154 126 58970 7304-9 1 065 23979 28107 10734-1 319 13 3731 84 86 6 34 94 5 334 9.30 416 932 909.051 530 205 1534 329 586 971 727.107 10.601 23865 5 2X6 737 305 918 13 X25 132.183 8210 38 7 19 058 73.587 227.383 495.771 29. 59 836.671 320 l11 396.544 5 782 1303 72 156.318 166 %39 7 540 383 363 4477 71 8 3 062 11 709 36.130 78 885 46 030 133 128 50936 63 097 .920. 207 3 3 24 882 26.547 1.20(3 28 806 712 48 9 3.072 4.139 12 789 27.884 16 263 47.057 38 004 22.303 325 73 23 8795 938X4 424 If 180 25 184 I0 000 .000 003 .003 .0002 .004 002 .002 000 03 I 0o 001 000 003 02 II 2 360 11 140 2S 769 56 386 32 770 9-3 820 .6 279 .4 9.30( 65 5 1347 3 2 7722 30R1)(1 X.l 205331 5(7 36 12 3 0'9 5 828 31 007 39 262 22.899 66 258 25 353 33 4(03 458 303 09 3 2 384 33 232 597 44 .47 354 60 all vcar 7( 237 273 203 838.032 3827 146 3065 685 3083.522 1179.713 1461.448 23 308 4797 45 576 326 614 811 27 788 667.670 16502 45 ITabe 4-4-9 Nlonthly BOI)N Load of the CRtchlimlenit of Tributories of the Yongjinng River in Nanni muulih R 8liibu R4. [uoI2i. R. IRI\Il R. Keli R . iig _ -arkug Nauuli Zl t.hipa,ldolng Nanan It. hang enI 4 R. Fenghuang R. Machao L3eian lingzicliong Total 1 2 3 4 5 6 7 8 9 10 I I 12 13 14 lottal I 1 146 4.734 11.688 23 825 10 761 3(0.X44 14 044 20.780 .252 82.93 6.086 7 401 .237 6 353 221.09 2 9(05 I 7.17 ) 223 128 X05 X 493 24 145 1 1 ( X- 16 406 199 65.46 4 X03 5 X41 .87 3.(15 174 50 3 274 1 132 2794 5695 2 572 7 371 33157 4 969 .060 1982 12433 1 769 057 1. 19 52.85 4 047 196 484 986 44 1 276 581 .860 .010 3.43 .252 .306 .010 .263 9.15 3 1.464 6 046 14 925 30.424 13.741 39.387 17.933 26 543 .321 105.90 7.771 9 451 303 8. 13 282.32 6 8 9X3 .37 097 91 582 86 680 84 314 241 678 110038 162.866 1.972 649.81 47.683 57.989 1.860 49.782 1732.33 7 3 566 22 986 56.746 115.671 52 243 149 749 68.182 I10.915 1.222 402.63 29.546 35.931 1.152 30.846 21 73.39 8 1 3(4 5 1846 23296 27. 12(2 2 241 315 X86 I 5 975 23.645 286 94.34 6.923 8 419 270 7.227 251 50 *) 574 2370 3x3o I2 924 5J8X6 2343J 7.u20 104403 126 41.51 3.046 3.704 .119 3.180 110.65 lo 0ss)tl "z00 ((2 t1 .0o08 O (104 020 010 107 000 0.1 .(0(2 002 .000 .0(12 .)7 1 ) 998 4 120 1(1 171 20 733 9.364 26.X41 12 221 1 X.08 .2129 72.17 5 296 6.440 .207 5.529 192.39 12 175 3 105 7664 15.623 7(056 20 226 9.209 13 630 165 54 38 3.991 4.833 .156 4.166 144.98 :til wal 1 220231 9()Jt) 224 -12 457 475 206 619 592 251 269 65X 199 116 43.13 2392.40 226.832 142.107 4.557 121 993 4245.22 The actual points at which waste water is discharged into the river can be determined on the basis of the different plans in the feasibility report. (2) Non-point sources Tables 4-4-7 to 4-4-10 list the load of BOD5 and COD from non-point sources of the drainage's of Nanning City based on thc analysis and prediction of "Studies on the Planning of the Environmcntal Capacity and Water Quality of the Yone aang River". The time of this assessmeint extends to the y'car of 2015. The non-point pollution source load is 1.3 times that of the vear 2000. As the non-point sources load was calculatcd oln thc average rainfall over many years. it mav not tailv with the different time appraised. So sonic rough adjustment was made according to the designing runoff ratio. Taken into consideration was mainly addition of the increase of non-point sources during the high water period. Q,_1800 K = - = 1.32 ) 11360 As for the loxw water season and normal periods, the onainal designing shows that non- point sourecs then are comparativelv fewncr to be within the rangc of safety. so no adjustment was made for these two periods. Table 4-4-12(1-6) lists the non-point sources load after readjustment. Table 4-4-10 Existing Non-point Source Load of Drainagc's in Nanning City Drainage Nk. I 3 4 5 6 7 Draiinage Shipul:C I hgtnt.CIIJ1.nj KC.ijlzltn Xinmupang Erk.nc D)ak.nlg N;UIhu .krcXtj 4ki ) 9 3' 01) 606 00 1 Q it3) 5(I) 14 44)11 SS (t a) 3.044 2'fl 12.152 700 23.X93 1 2 46.020 5 50 t, 951 Ifl,)17 614) 2.455 (064 ('OD\11 (L ) 16 597 03 515 18.3 235 403I 298 24 (Ic 3 5919 226 64) C(i)DCr (t) 701237 271 201 80.1 2 I.827 146 ). ".5 x55 .083 5:22 1. 17) 783 1(01)5)(I a) 22.013 90 909 224.428 457475 2t!t .) 592 251 2t.9 6'5 1'.P kta) 0.741 971 6.019 11 633 I t 3458 1 366 Tr-N T) 31 iso 124.7tl 244.2x | 4f67305 26 95 71 1 o 1)771 D)r.kiage ,. o 8 9 10 11 I 1I I )ral4n.lc Zihupalch'n g Na.i'.m I hanIg IifJng Fgi iilw \- 1.1. haolic 1H IJII iuo&i oig .\rea (kni-) 117 oon I 200 591 00 25 o0o) :o 000 : 60 3 500 SS(t J) 41,25J 29' .79 4()6 22.147 70 J4.4)5 X69 I 2 o 21w. 5181 1.152 251 I(VIIl tt a) 319.60t 4826i 1.13502 122902 j .3S 61)5 5278 1.10 X04 OtL)crt a) 1.461 44 t 21 308 4.797 45 575 126 |14 8I 0 p 7xx 667 670 iIt0)s(t .1) 339 116 4 81. .52 40 116 X52 1 42 1f), 4 i57 121 995 F i'o .1) 10 37 ( 095 55 52 1 23(4 293 410 )20 )7X5 FN(t a) 419 9)6 1 6x') 2,345 3,3 tx 26 1 |J 19s )9 44229 11 20' I.,Ia .\Arca (kii- SS(t.) C0l)1 )f I t! C()I)cDr(tI ) I It M 1)ls) Ir,.1) TN(t 4) 1.072 96 345.50)4 24) 3.61o 57 16.54)2.4.6 4.245 22 9 5) .48X9) 17 77 Table 4-4-11 Predicted Non-point Source Load of Drainage's in Nanning City in the 1'ear of 2000 I)rainage Shipuhe Luowenjiang Kelijiang Xinxulijiag Erkeng DAkeng Nanhu Arca(km 2 9 000 35.000 86 000 132 000 11 000 30.500 14.40 SS(iia) 2.X93.863 12.235,75 24.481.9S0 47.951.700 1.577 342 10.347.370 4,185.022 COD(Mnt/a) 13 152 113.604 290 266 619 430 237 856 771.59R 406.014 COD)C{tia) 54 398 525.033 1,345.934 2.S79 164 1.156 900 3.7S4.496 1.995.500 B3OD5(t/a) 19 172 135.609 313.379 649.444 _02 611 717.126 369.526 Ip(L'a) 0702 3.070 6.249 1 2.3'2 1.238 3 782 1.692 T N(Ua) 29.801 122.463 242.082 473.069 26.462 67.4?0 20.900 Drainage No. 8 9 |IO I I 12 13 14 Drainage Zhupalichong Nan'aui Liangfengiiang Fenghuanghe Machaohe Beian Tingzichong .V,a(kn2) 2 117.OO 1.200 59100 25000 3000O 2.360 3500 SS(t,a) 41.912.710 45 A82 22.7693.70 5.725 908 6.X1.334 76.470 2.243.900 CODM4n(tia) 495 231 3.141 1.303.4S 534 854 410.710 X 439 210.718 CO)DC.r(La) 2.311 907 17.366 5.64 96 2.612 463 1.98Xx 4XO 40 I X5 1,030 11f, 1101)5(1a) 529 441 3.810 1.740.51 447.843 337 978 5.950 176.264 'T'P'(t.'a) 10 674 0.016 55.68 2 237 2 290 0.032 0.878 IN('al) 41< 171 0.246 2.331.97 35 053 54972 0406 13.574 ITowtal Arga(Lkni) SS(La ) *CO)tnilW(a) CODCr(L'a) TtI)5(t ) 1P(L'a) TN(tL a) I .07' 96 390.252.30 5.418.50 25.4 2' 46 5,648 6' 10().36 3.833.84 (3) Contrast of point and non-point sources Tabic 4-4-13 shows thc contrast of thc timc and spatial distnbution of point and non-point sources flowing into thc Yongiang River in Nanning City. Table 4-4-13 Contrast of Point and Non-point Sources Load Flowing into tihe Yon jinng River in Nanning Mtitii Desipied 13([)c (L/d) CODc, (lid) COD1),, (L/d) I'olnit Non.-poinlt Point Non-point Point Non-point March 7(!25 3 475 6| 1).'9 1 2 J,nilr 2oi 132 J75L 725 IlS 161 Sept 73.3-14 o( 279 0 61 93 * I.280.00X 0 22 X1m,\zlutal.n 73 028000 609 ')3, 1.3 .0(I 0 21 I)akcng 71,.960i.0 2S100 6( 85 2.05100 0.14 L.inmlie 73i,963.() 'I10 fi 0 58 I.08O 00 0.26 ShuI:an2liuallne 74,6611 2)() 001 60 16 767 00 1)37 Q______ha"l.l 74.670 00 24 t00 59 96 1.402 00 0.20 lunmtiao 76.f82.0(0 292 00 59 40 1 f49.0 0.1 Li mli 78.046 00 297 0(3 5S 17 2,() 1.0) 0.15 It.iujir 7S,49f6.00 290(0) 5777 3,219.00 0 1 Table 4-4-20 Desioned water Level at l)iffrcent Sections Iesiigned W\ate rD )akenog Yzolwilanig lin.tZlioii' l a Santlaritini Slittingi ang Qingsltai 170 60 .14 A)1 1; I h( 1 7 ) 94 5( 7R6 59 560 301( 6(099 ') os" (6 72 (I .1' 60 .31 60. 12 6.340 61.51 ,I .4-1 1 63'7 6112 60.9?2 (6 76 I Six) 6i *14 31 63 07 t' 01 62 96 60 50 _ _ _ _ _ _ _ _ _ J _ _ _ _ _ _ _ L _ _ _ _RR The depth of water at different points of the simulated region can be indu;id from the data of the topography under the water of designing water level, and the flow s5eed at diffcrcnt points can bc detcrmincd throughi the folloxving relationship: q = ho(_b, h qI h In whici: q -- pcr width wvater flow h -- water depth qh -- average per width water flow and water dcpth of the sections bO.b1 arc parameters, when the section is a rectangle %khich can satisfy the Mining equation, bo=1. b1=5/3. Based on the topography data measured and diff&rent designing wate- levcis and take bi=5/3, the values of bo at different sections can be wvorked out: Wharf in the upper reach of Dakeng: bo = 0.95-0.97 Zlhupaichong: b0 = 0.94-0.96 (flood season bo = 0.78) Tingzichong bo 0.81-0.87 Fomier hydrological station: b( = 0.95-0.97 Qingshan b( = 0.82-0.88 Tnese figures show that the width/depth ratio of thc Nanning scgmnt te. the Yongiang River is comparatively large. equationi ( 14) xvill havc desired results. ULidcr thc forcc of long timc \\atcr flow. thEc nvcr bed in the Nlannin_ -egeinict of the Yon iamg River is founid not to bc svimmictric and the topography shows a r.-earkable Icamig chiaractcr Wlicn there is no more detailed field survev data, usiig cqulation -1) \lill achieVe higher prccision. (3) Sclection of water quality simulation parameters A. BOOD attcnuation cocfficicit K, The BODO attenuationi cocfficicilt K$ is relatcd w\ith thc concrete cha.1cteristics of the ri\er. and its attenuation can be divided into CBOD and NBO[). and 1K, can a!-e be divided into K1, and K1K,i BccaLise the flow spced of thc Yongliang Rixer is f1a1irly quick. os.: thc attenuation of C'BOD wxas taken into considerationi in this stud\ The tiUle etTect of NBOD usually comics tie da\s later and it w%ill not bear anv influence unitil at 86kmil in the lox\. reaches at the aicrage wvater flow spcd of ().2111/s. Table 4-4-21 lists the Kt v-alue wvorked out In thc laborator\. T'hc a' ._eC Value at thC sectionis w\as 0.08X5 in normal periods and 0.23 in the lo%% w-ater season. Gcr.:7allk natural K1 g9 value is larger than that worked out in the laborator-v. Table 44-21 K1 Value Worked out in the Laboratory *______________ _________________ unit: per d Sectiol L.ow Water Scason Normal erinod I ligh Wk'ater Season Average L.aokou 0o n 00 . ( (8 -Xint iangekou - ( 1(4 - ( 104 Shuitanguiangkotu 0.3(0 1 0. JO (A( 0 17 Puttiiao 0.07 0.07 0.07 Table 4-4-22 Concentrations of BOD, Monitored at the Sections, 1991-93 Year Seasonl Dates Water Flov" Shititanigliang CI Pumiziao C2 a (I3Is) 0BODs (mngL) BOD5 (mn/L) C2/Cj lo, water Mar 11,22 260 2.85 1.(8 0.38 )991 hi2lh water Jun. 11.24 1465 2 67 0 0 41 normal Nov. 11.21 322 269 066 025 low water Mar 11.22 27( 2 f4 1 .)3 0.39 :992 higih water Jun. 11.24 4265 0 70 I 03 1.47 normiial Nov 11.21 I 2 2_ 5 0 1 71 0.32 lo waler Matr 11.22 25; .3.1I I 33 0 40 I 9 3) . iighi wvater Jun. 11.4 2 16'6 1) S( 0.88 1 02 nonral Nov' 11.21 47-3 1I 45 ( .74 10 1 It can bc seen by analyzing values oniotiLored as listed in Tablc 4-4-22. tlhe noll-point soLircc load of thc scement between Shuitangliang and Ptuiiiiao bcars much impact on the increase of thc BOD5 valtuc at thc Pumniao section This is reflccted bv the fact a > 1.(. When thc water flow is smaller. thcrc is no or little runoff an the region. and thc cocfficient then 0 25 < a <() S I W\ lihout considering the impact of longitudinal discrete. the K1 value between the Shuitangjiang sectionI and thc Pumtiiao section will be: KX a=exp(- -) (17) if Supposc u zl-5Im/s. x - 26f,((n).a =0 25-0) 'I . Tlicrn K1 = -Ina = 0.',-, - 069/c/ (18) x The value is hligier than the maximliLumn \aluc in Table 4-4-21. wlich means the values %%orked out in the laboratory can be uscd as tile lo\\cr limit of thic K, value. Thc actual K1 value shiould be larger tihan thc one estimated above as the longitudinal discrete was not taken into consideration. The range of the K! values in designing: The Lowv water season and normal periods: 0.07s1, 3.8mglL DO = 6.9mg/L High water scason: BODs = 0,img/L COD,,,, = 2.2mng/L DO = 6.4Smg/L Normal periods: BODs = 0.70mg/L COD\,,1 = 2.4ntig/L DO = 7.2mg/L Tllc values taken as a wholc arc safc. - Prediction of water quality and contrastivc analysis *Simulation of present \%ater qualitV *Water qualitt analysis during the construction *Watcr qualitx simulation in normal water level years C'ombiiation of factors in thc plan 93 *\Wfater flow: 170m3/s. 630m3/s, 1,800m3/s, 300m3/s * Norrnal vcars: 1995. 1997, 2000. 2015 *Level of treating: no treatment (r= 0), level I (rj>30%), level II (p1>83%) * Pollution discharge outlets: Zhupaichongkou (designing plans I. 2. 3) Shuitangjiangkou (designing plans 4. 5--recommended plans) Dakengkou (present plan) See Table 44-27 for the actual combination of plans. As the impact during the construction is mainly within the Chaovang Stream, the table does not include that in 1997 when the dredging of the Chaoyangxi segment is finished, that is to say, the asscssment of the impact of the construction on the %vater quality of the Chaoyang Stream is given in later parts of this assessment. See Figg. 4-4 to 4-6 for the results of water quality simulation. 12 simulation plans were made for BOD-DO and 4 for COD,i. The segment calculated is a 13km segment from the upper reach of the Erkeng River to the point at 4km in the lower reach of the Shuitangjiang Stream. The efficiencv of level I and level 11 treatment is low in actual CODi)n simulation. respectively being 10% and 15%. Most COD v1n values vere estimated by deduction from CODCr. That is to say, most of the prmarv treating rate is of COD.%., part. and the estimated value of CODCjCOD\ =4.4, equivalent to CODC,-.,iWCODr=O D .48%. That is to sav, onl w%hen thc COD allowed to be treated is above 80%xwill it bear much impact on CODin. In the actual calculation. the point source load of the Xinyujiang Stream and the Kelijiang Stream -was added onto the background concentration at the upper border section. The load of the Machaojinag Stream wvill be discharged into the ShuitanLitang Stream in 2015.. and so the non-poitit source load was considercd in the high water season (water flow 1.X00Oinv/s) plan. Table 4-4-24 Combination of Water Quality Simulation No Desirrin2 Rlintotl' of Nonnal 1'reating Dischargc Ot,tict Simuilationi Plan R Yonegiazmn (m'is) Year Load Level Location _ i 7() 1995 No Dakcn2kou I1rcscit _ ItIs() 1995 No D)aketndou quality 63() 1 )995 No Dakcngkott 4 1703 200H 1 Shultigar iantkoou Year of Reconiicnded 170 20(3O 1 Zhupaichongkou comilplCtion ( Comparative 0 . I 70 3) 30 li 7.hupaiclhotikou 7 170 2015 I Shuitanig2ianiikou .i; 17(1 201 x 11 Slitntaie; iaimiroti Nomial Recommeiinded {v 180)() 2015 1 Shuttanielan-kou designiiiig In1 630 .(2015 1 Slhuitgnati2.kou year_______ I l 3(00 21:i I SlhuiItamigiazigkou Nornal swar Flei Reservoir I i 70 201 j No 1)aken2kou Nonnal wcar Comparative 94 0 1 oo0 2000 3000 4000 5000 500C 4000 r 00 Zhupaichong I ~~~~~~~~~~~~~~~~~~Streanm 3000 3000 Dakeng -\ 0'i /t1 2000 Stream Erk-eng Stream I Ovo -4 1000 Coordinatr unit: m Sliuftangfiang Concentration unit: mg/L Stream 1 0 1 - I I I i - I I 0 0 1000 2000 3000 4000 5000 6000 Fig. 4-4-1 Distribution of BOD. Concentration under Low Water Condition with 1995 Year Load 0 1000 2000 300C 4000 5000 6000 I I 1 - I 40C0 0 Z/:up;uc/mng j4000 3000 *- /i \ 730hOC Stream 7 ~~~~~~~~~ 2000Stea .Strearn Coordinate unit: m \ Conce:ntration unit: mg/l. .'zwiitjwng .Streaznt 0 ' I 1, I L I 0 0 1000 2000 3000 4000 5000 6000 0 1000 2000 3000 4000 5000 6000 4000 Zhupoichong 4000 StreamN 3000 3000 Dal;eJ tg , 4 ~ \ ' / / I i 2000 Srrean t Erl;eng Stream 1000 1000 Coordinate unit: m Concentration unit: nigIL Slzuuangriang Strearn 0 I I -- 0I I I -0 0 1000 2000 3000 4000 5000 6000 Fig, 4-4-3 Distribution of BOD, Conecntration undcr Normal W'ater Level Condition wjih 1995 Year Load 0 000 2000 3000 4000 5000 6000 4000 4000 izJupaiclhongs Stream 50^'3 ! ,4n'vX - ''', !^-s~~~~~~~~~~~~ 3C,0 -~~~~~~~~~~~~~~~~~~~' -nCr, t-/ / i / / \, 20C5 E:rkeng -: Sitream / / -- 100 Coordinate Ullit: m SmIIIIIJq1algtn Concntragion unit mg/l. Streanj i I I _ _ 1- i ._.1. - I O 0 ) 1 000 2000 3000 4000 5C-O 6000 o in. 4-4-12 )istribution of r0D Concentra ioi under Lowr WaterCordition with 2015 Year 3500 4500 5500 6500 3500 500 55o0 6500 )00 _ ' _ 4000 4000 _ ' 40( Z/i cI/pa/Ciong Z/Aupaichiopnr, S,irealnSrem ~4- 000 ~~~~~ ~~~~~~~~~~3000 3000 3 0( 000- _ 2000 2000 - 20 Shuwilangliang .S11lnilan1,1a(ig Coordlinate tiliil: 111 Streant Coo)rdinte;lt Ulii: Im streall, Conccntration unit: mg/L .Consceiiralion tunii: mig/L 3500 4500 5500 6500 3500 4500 1-500 6500 Fig. 4-4-4 Distribultion of BOD, Concentration undcr L,ow Water Condition Fig. 4-4-5 Distributiion ol'BO)D, Concentratlion uliidcr L.ow WValer Con,dilion wvilh 2000 Ycar Load aftcr Lvcvl I rrcalmcnt at Shuitangjianglkou sih20 crLa fc cc Cltei lZuacln K ( 3500 4500 5500 6500 3500 4500 5500 6500 :) . t _ 4000 4000 _ 4000 Zj,t4paicIiVP?g Sireamt lSrbll o 3000 3000 3000 /{ /I/ I 2000 2000 2000 0~~~~~~~~~~~~~~~~~~~~~~~~~~ 1000 1000 1000 Coordinate Ullit: nl Streamn Coordiiiate unit: m Coontraion l uniil: ngil 'oncentraion unit: mg/L 350 4500 500 6500 3500 4500 .45500 6500 IFig. 4-41-7 D)istributlion of1301), loncenirnaion ,n'fl,k Ir / 1:: ' '-( ^' -:'stti,^ 4"()-- 'enctrwe; .... 11(1(rIlkrm I.... \t,tilitill 6500 3500 4500 5500 6500 3500 4500 5500 65 4000 4000 4000 Zhupai4000 _ I 4000 - \ ~~~~~~~Zhupatchong Z7j14p)(olilo?g Sitream 3000 3000 2000 8 /' B ,%, / ° 1 2000 2000 2 2 iooo 1000 -ji: ,/ -1 Coordiniaic tinil: m Coordinate ulnit: m Streann Concer,ira ion linit: -ngl .Strearn Concentration tinit: mg/LI 0 ------~.-.I-0 0 . - -.-._.L n350 4500 5500 6500 3500 4 50C0 5t'02 6500 Fit 41-1.-9 D)ilrillulion li Aic Cl) (inceiniralln ilntlu r I u1g1 Watelrl Condiion l:ig4.4-4S Dlistr ibtiliono {111I), ( eoilciilr;iiiotitiidcr l o%v Walcr ( linelilioi 2 Trcatlcnt at Shuilangiingkoui ' di 215 Year I Liodalter I evel I 1 reililiclilm c ii Siilingjiailgkoi WithI 201I5 Year Imid ale It vcr.ey) ,00 4500 5500 6500 3500 4500 5500 6500 .-.---.-- 1-..i-.- - * - - 1- ----4- --- --- - mX-- 1 4000 4000 __4000 Sei-eun ~~~~~~~~~~~~~~~~~~~~~~~~Streanm 3000 3000 3000 2000 2000 2000 Coordiniate uliil: Im AlrtifangUianlg 51ltuilangiiantg COnicenlratiotl unit: mig/L Sitream/ Coordinate unit: m Srreatm Concentration unit: ing/l. !01 ___ __ § 0 0 0 00o u50(. ruS00o 6500 3500 4500 5500 6500 C tig. 4-4-1u Distribution ot L30Dd Conccntration under l.ow Wnnir Condition :ig. 4.4IU ()istribution ol uBp0) Couicenltrtiion under Normial Water l.vel Colldition with 2015 Ycir Load tfler Level I Tlreitmnenl 'wicn the 1e3ise 0 1000 2000 3000 4000 5000 6000 4000 - 4000 ZhEoaichong Stream 3000 2,. 2000 2 _ ' 2000 1000 1-000 - Coordinate unit: mn Situziang,iawug Concentration unit: mg/L Streamn O 1 I 1 1 1 1 1 iI I I ( IL C 0 1000 2000 3000 4000 5000 6000 Fig. 4-5-1 Distribution of DO Concentration under Lowv Water Condition with 1995 Year Load 0 1000 2000 3000 4000 5000 6000 I I I I IIiII ! . i -, 4000 ZhUUIl Oftt l$4Zf0 j, _ 4 S 40(o ~~~~~~~~~~~~~~~~~~4r00 Streain! 3000 3 2'9000 _ ~ \ 2 \ )/ / / 1/ / i_ 2~~IV Dakeng - mnoo A IC.QO Coordliiate unit: m Concentration unit. mg/L ShU:tangazjng 00 I _ 10I00 . I I l I !Streant 0 0 1000 2000 3000 4000 5000 6000 Fig 4-5-2 Distribution of DO Concentration under lfigh Water Condition with 1995 Year 1nad 0 1000 2000 3000 4000 5000 6000 4000 40( Zliltpaichong 4000 Stream 3000 _ 3000 J6~~~~~~~~~~~~~~~~~~~~~~~~- 2000 / - 2000 Dakeng 2000 ti* i E;rkeng 1000 1000 Coordinate unit: m Concentration unit: mg/L Slzuuangiang Stream Q f I I - 0 _ lI _ 0 1000 2000 3000 4C00 5000 6000 Fig. 4-5-3 Distribution of DO Concentration under Normal Water Level Condition with 1995 Year Load U UvU( ZJUu Juuu 5uVQ S000 6000 I I I II I. I I I I -,y 1 4000 _i( paiCIo,g - 4000 Streant 3-000 - . 3000 o 000 /2000 D)ak;eng 11 / + A 11// Erkceng s J z 1.000 10 -Coordinate unit: m S/nutaagjiung Concentration unit: rng/L Stream O 1 1 . . 1 1 1 I I I I .1 . I .L l I I O 0 1000 2000 3000 4:.3o0 5000 6000 Fig. 4-5-12 Distribution of DO Concentration under Low Water Condition with 2015 Year l oad without any Treatmcnt 3500 4 500 5500 650C . - '\ It~~~~~~~~~~~~~~~~~~~~~~ 2000 2000 2000 / 3 0 0 0 ( : / \ \ 7 $ \ | 5 ! f i l l a q 0 r I 1000 C / / - ." ' .~~~~~~Stretwni CordnjlrelIl;C iil 11. mIII etn C nordiliac tll1111II (oor(hnnte unitConcentration uns[ ing/1. .VrconC,nc nr1 .on an. '(1'/7 Ci' nccnlratlon unii: img/l. (ocnrln znlm^l 0 I I I I 0 0 3500 4500 5500 6500 3500 4500 7-5(K ,5OC Fig.4-5-4 Distribution of DO (oncentration undcr Low Waler Condition with 2000 Year l.oad aI ig .1I5-S D)'%ribulmn o 1 )1) (onccnrilraion iin(tcr 1 .ow Waler ( t'lni700o il lit 2000l 'cai ShLiangliangkoie aflcr l.cvel I rreatment I , 1 /t1a lp;/ tiinp .1lics I C% el I I mamcmtlI 3500 4500 5500 6500 3500 4 500 5500 6500 _______ _______________ ; ' ' - f i 1~~~~~~~Ij I I l 0 4000 4000 4000 I ~ ~~ ~~ -E ./I,}ltl¢}g) I~ ~ 0' II II N ~~~~~~~~~ ~~~~~~~~3000 3000 300C nr. 11\111o>,*/ °0'°' ° I, Ut. W AJJ,,,,, jlEe - ~~~~~ ~~~~~~~~~~ ~~~~~~21000 2000 ("200( r ~~~~~~~~~~~~~~,~~10 1000 10 111111 nh1114M ,_ sr*.lEw ('tll)~~~~~~~~~~~~~~~~~~~~~~~~ordinmel t illl ill ( suucciutr:uI tuit It(Xc) II1),-I ,' '0 )1 65.00 h r Of1 oi 1)() Concen1traltion tinder .o%% Wvitter Ciiditln sitht 200t Yeair lFig 4-5-7 Distribuuton olf DO Concentration under Low Waler Coondition with 2015 Year ~ 4.5m6hI o)s r a trlofl of I )( )' one n I n un der 2 \V1 aer, il d Load at Shuilangi iangkou afher L e. ve l 1 Ire atm en t t,54tt1'' ~ ~ ~ ~ ~ I '$l' 1 1 IUtjI!-) I8 Z 1.3,0- I,@:1 ld 11111! IIj&II'IIII IV IW I J .) tI It ' ) I W H I I , l tJ I LtO LI I I. ) ( 1 1 1'' In cl I I I I J l ! . ' k ~ I O[ t j llA % U O t ! tP U0t) J ,) I I ! A \ A N W I J 1 5 lU ' L i l u xl w olU !) ( (i j o ui ll t qjl Si ( X -1-1 |) ]09 30CJ 00s; 0059 oo00; O 07 O0G2 0 0 0------r- 0 8 /wta,2,ls,~~~-I/tt I2 lit I I tlitIII vj ILI.tlls, 10;ttl iititi tlOl Iiluont.mtl.) 1- Ltd _ VgDlU/IIIt ! , .lilrtil,'lldl,< v§ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ltl t ,'O,OOLwaX '°°°I 0001 A ,_ _ 'u0 0001 0001~~~~~~~~~~~~~~~~00 ,lN :'', -. I / I! (( i I,i i ,/ , , 0 . ! o i ~~~~~~~~~~~~ooc>ooo z oooz /1 ~~~~000 ool I I", ,',j .11 000V~~~~~~~~~~~~~~~00 o o L; 0 . I i ; 1 o c.1 .-_ I ;)0G9 ~ ~~~~~ ~ _______0g OOOc'rrr >ettC 4 500_-oo 6500 3500 4500 5500 6500 4000 4000 1 400 ihqatc/_ ong f ,' .7 / . 7o2 2000 200C > t '~~''''~~''~'''~~' j;,-' 100( 1000 ' _' 'V'/1000 killi II NLl ncennraiilily ('t11i<'111'11111]tlllll 111v.'1. t50 X t, 3 500 35 00C 4 500 ss5 GS (00 I m;ak;1 lt,i,g ;,g ,, a flet Ir 1 ts11 're ;i1ill otte i s1lol S iill i;l l a ticrte N o m a Wevtt I~vc I,111 I 1 201 r5lil Y c I )~ ~ ~ ~ ~ ~~~~~~~Ia 1 1111gmlkuairICC Iriivci 0 1000 2000 3000 4000 50000 6000 I I I II~ i i 4000 i 3000 300 2000 / LiIo Dake'zg 1000 OQt Coordinate unit: m Snii:fngjt.ine Concentration unit maiL Stream 0 I-I_ I I 1, 0 1000 2000 3000 4000 50C J 6000 i p 4-6-1 Distribution ol COI,,. Concentration under Low Water Condition with 1995 Year 1load 0 1000 2000 3000 4000 000 65000 -1000 , , - 30100 _ 2000 Erke'ig Coordinate no tit Il i - '-' \ - L Cocnrtintit m"v-.-, 0 1000 20-!2 7 -D.3J 0nc 0 I:,- 4.6.2 1f)p;tribLuziOll t C')l)"1 (Xincentnttit)iuiiiuder low v. kater Condition ith?.9')cirIoi 0 1000 2000 3000 4000 5000 6000 .~~~~~~~~ I 4000 _ 40J 3000 -30% Dakeng Erkeng . 9 / / 1000 _C' -_' Coordinate unlt: m ; Concentration unit mgi,l SIzi,ilig,,smg 0 0 0 1000 2000 3000 40 C- 5000 6000 I-! 4-6-3 Distribution of COD)M.s Concentration under Lo%, \tater Condition %'uh 2015 IYear Load at Shuitanetiangkou aftcr Ie%el 2 treatmcnt 0 1000 2000 3000 4or. 5000 6000 4000 -Cj 300oL , -- -o 8 'aj~~~~~~~~~~~~~~~~~~ t 3' 3000 , 2000 /~' l~~~~~~~~~~~~~~~~~~~~~~~~ r I ordineetateo unit m1>1 0 I _ lf. ; ' ._ ._J 1000~~~~~~~~~~~~~~~~~~~~~~~ 0 1000 2000 3C000 :'.-. S000 FIw 4-6-4 Distribution of COD,, Concentration under l.ol Vkkmer conditiol with 2015 Year (1) Impact on the vater quality of the Yongjiang River during tihc operation of the project Tables 4-4-25 to 44-27 list the different length and width of polluted belts as a result of different plans (taiking the standard for Grade IIl surface water as reference). Plan I rcpresents the present load and discharge while Plan 12 represents the load of the year of 2015 without anv treatment. both using the dcsigning low water year with a water flow of 170m3/s. At the present load, the BOD; polluted belt at Dakeng and Erkelng is 1.740m long and 75m wide, that of oxygen dcficit -4Om long,- and that of CODS,, I 540rn long: at the load of thc year of 2015. the BOD5 polluted belt wvill increase to 5 520m long. which w\ill join the polluted belt of the Tingzichong Stream to block the wvhole watcr surfacc. and the oxygen deficit polluted belt at Dakeng wvill increase to I 000m long, joining that of the Tingzichong Stream to block the whole river surface and the latter will join the 500m long oxygen deficit belt of the Shuitangjiang Stream. The COD.t, pollutcd belt will increase to 4 700m long. also joining that of the Tingzichong Stream to block the whole rivcr surfacc. It can thus be seen waste water discharged in the drainage areas of the Chaovang Strcam and the Erkeng Stream must be gathered and treated at present and in the future. as the length and width of polluted belts under the designing low water conditions %xould be unacccptabic. Scrious pollution will appear in whole segments of the river under the designing norrmal years. The tabic shows the realization of the Chaovang Stream comprehensive treating project 'vill cffectively guarantee the water quality drawn by Lintic Water Mill. W ithout the project. water quality wvill detcriorate so greatly that its BOD, conccntration \will reach the value for Grade V water, but the project can improve it to be within the standard for Grade 11 water. Plan 2 and Plan 3 respectively represenit the present pollution load during high water years and nomial wcars. Tnc BOD, polluted belt at Dakeng and Erkcng wvill reach I i00nm. cxccedine the limit of I (O()lt. So it is neceSsar\ to treat the waste w%atcr of the C'haoyang Strcam drainagc arca even during higih water and normial years. Plani 4 represents the load of thl \ car of 2000 aftcr the completioni of the project. and Plans 7. 9. and I( represcit the 2015 \car load with thc completion of the project for lo\\ water, high water and normal cars. Calculation finds out that with the project in operation the polluted belts in Dakcng and Erkeng wvill disappear: thosc in Tingzichong and Zhupaichong will rcniain wvithin the standard for desired water quality: the pollutcd belt in the Shulitanigiang Stream nill become longer but not wider according to the calculation: its length w%-ill be liitcd to 3 0QOnii in thc highi water scason and over 4 400m in the low watcr scason and nomial periods. As a result of the proiect. thc water quality of thc Nanning scgment of the Yongjiang River will be improvcd. especially that abovc thc Shuitangjiang Strcam. in which oxygen deficit bclt will disappear. TC pollutcd belt in the Shuitangiiang River will be longer f3ut as it is located in the lower reaches, where its functional demand for the wvater quality is less strict The pollutcd bclts In thc Shuitangjiang Streanm are narrox and close to thc baniks This is because of the characteristics of the local water \a M t9 Table 4 -4-25 Prediction on the BOD5 Polluted Belts in the Nanning Segment of the Yongjiang River unit :m Plan Dakeng and Erken | Tingzichong Zhupaichong Shultaanjiang Reference No. Length Width Lengthi Widtlh Length Width Len2th Width Ficg 4-4 1 1740 75 530 63 280 64 3580 92 1 2 1340 71 200 78 300 58 lI(i 50 2 3 1360 6. 250 65 60 60 800 68 2 4 no no 530 66 290 70 > 440( 98 no 5 no no 550 66 910 100 >44() 104 5 6 no no 550 66 280 64 >440( 98 6 7 no no 860 81 670 91 >4400 125 7 8 no no 860 81 400 70 >3'750 90 8 9 no 32 400 69 520 41 28Iu I0( 9 10 no no 470 78 330 66 >44-00 68 10 II no no 890 100 590 87 >4400 86 1I 12 5520 nver 2500 river 1570 162 >4400o 98 12 . dtli u ldthl Table 4-4-26 Prediction on the Oxygen Deficit Polluted Belts in the Nanning -Segment of the Yongjiang River unit :m I'l.n Dakeng and Irkeng Tingzicihongo Zhupaichiolig Shuinw zai1r No. Lens.gthl Wizdthi Lcngil Width L.ength Widtli I ensth Width FtLi 4-3 I .340 44 51 70 n1o 1 ;s0I10 82 S 2 noo no no no no no no 110 ; o nI no nio nio nlo II( n1o 2 4 noo no o no nio no > 0t) 98 no 5 no no no no no no >! () 98 5 6} 110 ItO 110 110 0 no 41 9() f 7 nto n10 Ito no n1o n1o 'of) 9')S 7 8 11M 110 no no no tno 8./2 IS 9 nio .2 tio nto nio nio I of 1 64 9 10 10o 110 n o nio n1o no ">;50) 6S 1(1 _ 110 110 110 110 110 110 * '-t4 Hi I8 II 12 no no nio IIO nno )12 II( Table 44-27 Prediction on the COD1 Polluted Belts in the Nanning Segment of the Yongjiang River unit: mn Plan Dakeng and Erkeng Ting7ichong Zhupaichong Shui tangnian2 Reference Fia. No. Lengtil Widtlh Lenth Widthi Length Width Length Wk idth W idth 4-4 I 1z540 134 480 80 170 56 >4400 90( 8 no no 520 94 390 70 >4400 109 2 I I 1060 100 480( 8. 350 75 >44400 79 . 12 4700 ri ver 1670 nfver 516 91 >4400 7S 4 _ width _ idth Table 4 -4-28 The Quality of Water Drawn at Lintie Water Supplying Plant Plan No. BO15 (mg/L) DO (mi/L) CODM,, (mir/L) Note Plan I 3.07 6.13 5 14 Existzni load P'lan 12 7.38 5 37 7.05 2015 load withouc thls prOqtict P'lan 8 1.78 7.14 3 73 2015 load itlth this project . Plan 8 is similar to Plan 7. onl, its treating level is raised from level I To level 2. the BOD5 polluted belt in thc Shuitangjiang Strcam decrcases to 3 750m and that of oxygen deficit dccrcases to 3 560m, still somewhat over the limit of 3 000m desired This can be solved bv taking some other measures along with the development of the econiomi Plan II and Plan 7 are similar except about the water flo%w during thlc lo water season. Takcn into considerationi tihat thc Beise Reservoir %%ill soonI bc constrLcted. tlhe water flowx desigined in Plan II is 300nm3/s Compared with Plan 7. it can reducc the \ idthi of the polltied bclt in the Sluitangjiang Strcam by about 40iii Conclusion of tie assessment: a. The projcct w-ill greatly improvc the cnvironnicmital wvatcr qualit% of thc Dake;ng and Erkecng Streams. Their polluted bclts at thcir otitlct along the banks of thic Yong iang Rivcr will disappear. This \vill play an important role in rcalizing the goal of tirning thc city of Nanning into a modemized garden city. b. The project can collect about 35% of waste water from the urban areas of Nanninilg City after its is compIcted. Thic waste water xvill bc discharged into thic YolonLiang Rm'cr after level I treatmiicnt, and 10% of BOD5 load can bc reduccd. It provides a foundation for achicving the goals of pollutant total control of Nanning City In accordance with plan. the construction for level 2 trcating will start immediately after that. and thcni thc Jiangnan wkastc \atcr trcating plant will reachi desig,ned capacity, that is. 70)% of BOD% load will be reduccd to bring, niorc rciiarkable environmental benefit.. c. According to the plan of this comprehensive environmental treatmiietit proicect. a wastc \\atcr treatling plant of level I wvmll be built at thc outilct of the Shuitangliang Strcam in the near ftiturc. and later it wvill bc enlarged to reach level 2 treatinig abillt\ . Thiis talliCs wkith the reality l lIt of the economic development of the citv. It is more rational than to build a level 2 waste treating plant in one step. d. The project is necessary and urgent viewved from the angle of the city's water cnvironment. It is recomrnended to put it into construction as soon as possible. B. Analysis of the project's impact on water quality during its operation Most of the waste wvater in the Chaovang Stream will be drawn out through the trunk pipelincs along both its left and right sides after the completion of the first stage of the project. Water will then be pumped into the Chaoyang Stream from the Yongjiang River to maintain its clcanness for the landscape of the city.. The water supplement pumping station has a capacity of O.4m3/s, able to change the whole water in three days. The quality supplemented water can meet the standard for Grade II[ water. When it enters the Chaoyang Stream the supplemented Water bod- basicallv remains stagnant with verv low oxVgen restoring capacity and the wvater quality will soon deteriorate to exceed the standard for Grade IlI water but still meet the standard for Grade V watcr of landscape, just likc a small lake or pond. So it is possible for the water bod\- of the Chaovang Stream to mect desired demiand. Thhe water quality of the Chaovang Stream can be thoroughly changed if proper water exchange or replenish period can be used as wvell to solve problems like foul smell or eutrophication of the wvaier body. Bcsides. artificial springs and waterfalls can be added to beautify the vie\% and increase thc restoration of oxygen in the water body. so that the water replacement circle can be longer. During stomis in the wet season, some waste water may entcr the river through the sluice gate on Youai Bridgc. But the timc of ovcrflow will not last long, and so is the timc of its tmpact. Thc large amount of wvater cntcring the river can directlv dilute the overflown waste wvatcr. Therefore. thc dcgree of pollution wvill not be serious cxcept during the first rain. As it will last only a fe\ days. the pollution broughit by the first rain will not cause serious impact on the environmcnit. Sonic water of the C'hao\anlg Stream cnters the Yonilianig Rive during wxatcr cxchangc. But its quantity is not much and the water quality is near that of Grade V %atEcr. and the impact oii the Yongjiang River will bc limited in timc and voluImie. Conclusion of the asscssment: After thc compiction of thc first stage of the project. the water in thc Chaovang Stream will be improvcd from scvage to Grade V water to be ablc to mect the dcmand for general landscapc functioni during the dry seasoni and most time of the wet season. It is the direct manifestation of thc bencfit of the proicct. 4 4.2 'rediction on the environmenral inmpiact ofthscwt,e . svrem dierins?zt~ it'eration The prediction on thc environmental impact of thc sewage system of thc Nanning City during its operation mainly includes: analsis of its impact on the impro%ement of the citt's ccological system. landscape and vater bodics, analysis of thc effective control of the projcct on flood in the urban areas and the surface runoff that pollutes the city, and anal sis of the impact 112 on the eutrophication the water body of the Nanhu Lake after the separation of rain and waste Water. 1. Analvsis on the rain water pipeline construction There are altogether 13 sections of rain water pipeline. of which 5 flowk into the Chaovang Streamr, with a catchment area of 791 ha, two into the Erkeng Stream. with a catchment area of 1O8ha, 3 into the Nanhu Lakc. with a catchment area of 590ha. I into the Zhupaichong Stream. with a catchmnent area of 72 ha. I into the Tingzichong Stream. with a catchrnent area of 108 ha, I directlv into the Yongjiang River, with a catchment area of 38ha. The pollutants collected by rain watcr arc from non-point sources. w%ith various time and spatial distribution. Point sources produce relatively stable quantities of pollutants, though their distribution is uneven; while non-point sources have relatively more even spatial distribution. but the time of entering the watcr bodv is changeabic. mainly depending on the process of rain- runoff. Acceding to information from abroad and the experiment carred in Nanning in 1993. the first rains or the first storm each vcar is the timc vhen the most pollutants are produced. Different objects can be considered to analyze the environmental impact of rain pipeline. This assessment mainly takes into considcration two types of non-point sources receiving water bodv: rivers and lakes. As far as rivers are concemed. the project involvcs the Chaoyang Stream, the Erkeng Stream. the Tingzichong Strcam and the Yongjiang River. These w.iater bodies rcceive certain amount of non-point load no matter the rain watcr pipclines are constnucted or not, that is to say. With similar precipitation process. the rain watcr pipelincs can only discharge the rain accumulated on the strccts morc quickly. speeding up the flowv of runoff into the nrvers without chianging the total amount of non-point sources load. except that the peak value into the water bodies is sooncr. Accordin, to thc analy sis of thc general rcport and the data of monitoring over the water quality of the Yongiiang Rivcr--thc final waste water receciing watcr body of Nanning City--over the years. it deseives attention to see if this will lash the non-point sources of the rcceiving water bodics and cause the worsening of the pollution of certain water bodics. Thc water quality in high w\atcr period is bctter than in the low water penod. Thc Yongjiang River is a point sourccs controlled rivcr, thus these non-point sources bear no controlling impact on the pollution of the \atcr body of the Yongjiang Rivcr, nor wtil cause remarkable environmental impact the w-atcr body of thc rivcr. nhc main function of the rain watcr pipelinc nctork is to prevent flood and dischargc wvatcr accumulated at lo%w--k\in, places. so as to maintain the environmental hygienic and image of thesc areas. It is highly of civil engineering character. As for lakcs, this project inaolvcs the largest landscapc.water surfacc in Nanning Citv--the Nanhu Lake. The major problcm of lakes is thcir cutrophycation. that is the incrcasc of nlitritious substanccs of N and P. which cause rapid grow\-th of pl)vtoplankton. As a resLIlt, the w%ater body lacks oxygen and aquatic animials will die. and foul smells appear Abundant studies founid that the control of non-poiuit sources pollution now poscs as a ver\ serious problcm for lakes in China and in the \world as well As ticre is so far no good sewage s\stem and rain wvater 113 pipeline netxvork for the Nanhu Lakle area, it is obviouslv necessary to take into consideration the control of non-point sources pollution, and this will achieve double results if considered dunng the plan of the project. Othenvise there will be much regret. So the environmental impact of rain wvater pipeline network is one of the key points in the assessment. (M). Analvsis on non-point pollution sources The rain w\atcr pipeline network in Nanning City' includes 13 trunk pipelines, which can effectively collect (non-point sources) pollutants brought by the surfacc runoff of the constructed part of the city for planned collection and unified disposal. Non-point sources are the comprehensive reflection of various human and natural activities of the city. Their pollutants are usuallv accumulated and wvashed by the surface runoff to affect w%ater bodies in the lower reach. Its process is shown as the following figure |Atlilospliere of (lie citv D)ust talling- priecipitation mian ~Substanlces at ij;h Wasliting otf |W utce| |atcr bodies Irn | ierotinid surf,ie ninofrater the lower reacr Nion point sourccs are important components of pollution sourccs in the city. Usually thcy appear to be pollution sources without stable discharging outicts. accumulated \%hen the x\atdier is fine and discharged during rainy days. Thc discharge of non-point pollution in the cII\ is concentratcd in the rainy scason. especially during the first stomi after a long spell of drouhlit. "hien scriously polluted surfacc runoff will forn Its concentrations of pollutants may r.ach those of daily sewagc. Thc fact that the w ater quality of somc segments of certain rivers in China is wvorsc in high water lcvcl period is cause by the dischargc of non-point sources For e\ample. the Lijlang River in Guilin is of such a casc. A Composition of pollutants from non-point sources in Nanining a Accumulation of particles on ground surfacc Field sample taking and monitoring by Nanning Rescarcih Institute of Environmental Scienices and stimulation of artificial precipitation show that the amount of particles accumiiulated on ground surface in Nanning is 2.4-222g/m. the sample taken from the living quarters of the Guangxi Daily bcing the highcst. at 222g/lm(?). Sec Tabic 4-4-28 for details 1114 Table 4-4-28 Accumulated Particles on Ground Surfer in Nanning Quartos Living Corinniercial Industinal Traffic Sanipling point Nanning Guangxi Hiotigxing Dangyang Pharmaceutical Alanl1 beer Lingjiang Tinghiong daily theater Road factor' platt Road Road Volue ofsa;npling (g) 109 200 122 79.7 127.7 106 98.9 91.2 Area ofsamiiplitig (m) 4x4 3x3 4x4 31 3 4x4 4xt 40x 5 4 v9 -moLint ofpaniciles 6.8 222 7.6 S 7 O0 5 3 4 5 2 4 accuniulated Tim.s( Id) I I 3 25 l 1 2 2 b. Pollutants contained in ground surface particles Investigation found out that the amount of particles accumulated in living and comnmercial quarters is higher than in industriar and traffic quarters. This means people' daily activities produce more ground surface particles than production activities Table 4-4-29 shows the content of organic matters and N and P are higher around then living quarters of Guangxi Daily and beer plant is higher than that before Hongxlng Theater in Dangyang Road. This tallies wvith the data collected during artificial precipitation. Table 4-4-29 Pollutants Contained in Ground Surface Solid Particles ph1 Waler(%0) Organic Tl TN S-P N0,-N \Th-\ NIIN __matt.r(Io) (nigkg) (mgkg) (nikg Imgkg) 'mgkg) (nigkg) Giu.ingNi daily 7 L 2 54 % 71 0 059 0 274 25 5) 7 2 'I2 5 .uainlg 9 40 2 3 7 I1 57 ( 069 0 267. 68 5 < , 92 37 1 iiuongxinig -12 14( 7 R9 0 061 0 I4 41 6 _ 1 25 12 2 D)airigyang 9 70 1 64 8 58 fl 056 ( 19( 47 4 4 6 42 .1 22 3 [k:r plaIIt :8 53 262 13 12 0 053 0275 268 I e 42 14.7 pliamnacetic:1l 8 97 I 76 5 60 0 028 0 112 P') 5 '9 I . > 0.5 0.05 . 0.5 phenol CN As Hg ug'L Cr' Pb Cd Zn Fe Mn NO;-N NO.-N 1991 N N N N N N N - _ 1992 N N N N N N N . . - 6tMai .1993 N N N N N N N - . API.A 1994 N 0.005 N N N N N . .1av.1995 N N N 0.27 N N NS Apl. .1996 N N N 0.09 N N N 0.08 1 0.34 0 1 0o077 0 08 Mav. 1996 N N N N N N N 0.039 0.28 01 0.200 0 05 G113838-9 I 001 02 0.3 3.00 03 0.3 0005 2.0 0.5 0.5 30 2.0 (3) Analysis of thc wastc water recapping projcct and rain water pipcline project o3 thEc Nanhuii Lake A Prcscnt responsc of the Nanhu Lakc to waste water and rain watcr Statistics reveal that thc runoff pollution ratio of the Nanhiu Lakc over the years is 0.472. that is. thc amount of wastc water received is more than twice that of natural runoff rcccivcd. In low watcr -cars (P=95%) it drops to 0.36. Natural runoff flowing into the lake can no longer dilutc thc waste xvater. In low water period, the runoff pollution ratio drops to about 0.01. wvhcn thc lake is litcralIv turncd into a waste xater recciving pond. The amount of wastc watcr cntcring the lakec in the dry season is about 47 O()n()m. and stavs for about 36 days. Thc Nanhu Lakc is actually- an oxidation pond of waste water. During daxtimc the surface layer has mtich DO as the algae produces oxy,gen. At the bottom lavcr the DO is very low% at night because of oxygen consumption of the bottom clay (mctabolization of dead algae) and fish dic from time to time. Field monitoring finds out that thc wvatcr in thc Nanhu Lake contains largc amount of coli. but the water and bottom clav has no clear heavy metal pollutioni so far. This is becausc thie waste water it rcccivcs is mainly daily scwage. So it will bc comparatively casy to disposc the sludge dredged from the lakc. The water in the Nanhu Laike novw cannot meet the standard for Grave V surface water and 124 in a state of "extremely eutrophicated"' The lake can no longer perform its function of fishery and landscape. B. Impact of thc project of waste water intercepting a. Impact on the amount of water After the completion of the waste water interccpting project, all the polluted watcr from point sources will be sent to be treated in Langdong wvaste water treating plant and then discharved into the Zhupaichong Stream. The water in the Nanhu Lak}e shall be replenished by rain water An analvsis on the water balance in \cars of different water level was made on the basis of data provided in "Surface Water Resources of Guangxi Zhuang Autonomous Region (September. 1984). The amount of water entering the Nanhu Lake can be calculated by taking its land converging area as 6.7km2, wvith a water surface area of I .Om2. the total catchment area of 7.7m2, and the runoff coefficient a ' 0.75. See Table 44-36 for the result. In normal conditions. the amount of wvatcr in the Nanhu Lake is stable, retaining a water level of 70.3m and a capacity of about 1.7 million m3 during low water period. Table 44-36 Monthly Distribution of Water Entering the Nanhu Lake in Average Rainfall Years 1i 2 3 4 5 6 7 8 9 10 II 12 all %car raitniall iS 67 51.3 67.8 1580 246.0 173.3 3814 248 5 27 7 4.7 856 152 " Pp z0°o (niml) [ __I_ _ _ _ _ 41936) .Ilocrlgls .IlscI ir) 395 38.693 29.623 39.1 55 91 .245 142.065 100.081 220.259 1435.5)9 15 .97 2.714 49 431 4 883 171 (i0'tl) 'i ______ _____ cntiritig I.lA: 1 .135 I.3S2 0.956 I.305 2.943J 4 736 S 228 7 IOS 4 784 0 5 06 O090 I 595 O(1)'t i d) rtl.jA I 24 9 I37_3 7S 7 33 5 2 ;3 S 201.9 2704 224 ,5 I I O 10 *) 1') 0) 1' 50%° ct1l( IcLt i Sl 14. 380 21L541 4S449 195 4SJ4 1 U020 116.597 156 156 12936 l, 595 0058 6295 75) 17' 110 :0l' 1._ _ .nlcrmg LOi.Z '1279 0 514 0.695 1.515 6 S 06 4 SO1 3.761 5 017 0 411 1 213 0 002 0 2'): (OW'm'd) rainmll 27 4 81.1 1 .5 59.0 1911 () 280 2 144.8 165 7 5) 4 300 61 7 40 1 18o8 s P75°O Cut.nkrla,i4JL 15824 46.835 7796 .4.07 110 31)3 161.816 83.622 95.692 29106 17'25 35632 2SI 64') :2 10'il I) 1 - . _ .nlnring l;k4l 5 510 I 673 0.251 I 16 I 5f65S 5 '94 2697 I 017 )970)2 0 59 I 1S8 0075 t I O'iti' d) ! I ___ r;e'iu::ll 1 1- 3.9 3'23I 50.5 2577 2661) 56.6 145.6 1228 IS 8 55 290O 11))4 3 -95"0 1111 1954) ClItri,l 1 . s 72) 2.252 18 (653 2'9 164 14 822 15. 6 1 5 32.687 84,084' 74 093 7 9)70 : 1 76 16 748 579 IN Calr1:ig lak' 1 () ()8n 0.6()2 0972 481 x 121 I()54 2.712 2.470 0257 O 0 o 40 t1()'10ll-1} 1 I _ Data reveals that in Nears when the anlotint of lcakagc and that of evaporation arc in the 125 same grade, the average leakage is about 1.5 million m3/a. or 4 1 00m3/d. The anount of water consumed by irrigation and aquaculturc is not much and can be considered as leakage. Taking into consideration possible deviation of runoff and safety coefficient of water replcnishment, the amount of water in the Nanhu Lakc after waste water is intcrcepted corresponds to 0.05-0. Im3/s of the water flow lacking. b. Water quality responsc Table 4-4-3 7 is the result of monitoring over the amount of vater entering the Nanhu Lake (under nornal precipitation). Table 4-4-37 Amount and Quality of Water Entering the Nanhu Lake (average over the Years) v3lue (IO'[) C'OV(t) BOD,fl) TP (1) TN () TPRI Y Iotal value 2528.2 38472 1503.7 63 53 374 97 59 Conxentration (tng'L) 152 2 59.6 2 6 14.8 I'oinit value 1717.5 26R3 1 1233.0 62 09 351.53 5.7 percentage(Io) 68 69 82 97 7 93.7 .oneenlfrtion (mnigL) 156.2 71 8 36 20 5 Non-point valic 81().7 1184 I 270.7 1 44 23 44 16.1 FleCienta5c(Io) 32 31 18 2 3 6.3 ceocentratliKr (mngL) 4G6.1 33 4 I) Is 29_ Thic table shows that. with tie interception of waste water. the total load of pollutants will bc cut by over 69%. cspeciallv that of nutnrtious salt T'he amount of TP and TN is cut respcctivcv by 7% and 59'3 .75%. lhtis greatlv improving thc water quality of the Nanhu Lake But the amotiint of water repicnished to the lake is also cut by 6fiX%D. so the index of pollutants still cxceed tihe standard. If water can bc drawn from the Yongpiang River to rcplcnish the lake. the water quality of the latter will be gristly improved. (3) Response of the Nanhiu Lake to the rain water pipclinc project Thc rain vatcr pipcline projcct will be to the west shorc of the Nanhu Lake and will interccpt 88% of the convcrgc of the Nanhu Lakc , that is to say. the project can control over 80% of the, non-point sourccs of the Nanilit Lakc area. As rain water pipelines only Interccpt rain water without any treating. it has no bcaring on the quality of water entcring the lake. nic amount of lion-point vastc water cntcring the lake rcmaims thc samc only more rapidly. nhc amount of water entering the lakc will increase a littic during stormis. (Thc renovation of the old part of the city is not taken illto consideration hcre.) In a word, the rain water procect of the plan will not chanigc the serious pollution of the Nanhu lake. 4. Analysis on the environimcntal impact of,the rain water pipeline project on the 126 environment of the Nanhu Lake area The above analysis shows that the project of rain water pipelines cannot changc the present pollution of the Nanhu Lake. Non-point sources pollution still exerts much impact on the lake. OnlY by treating non-point sources pollution can the Nanhu Lake restore its water quality to the standard demanded by its functions. It can be seen that the present report about the rain xvater pipeline designing does not mcet this demand. It can be seen from Table 4-4-3 S. rainfall in June accounts for 17.6% of the annual total, but the pollution load accounts for over one third, cspecialiy SS, CODW, and CODCr. wvhich accounts for about 50%. If rain water does not enter the lake. the pollution load entering the lake can also be cut bv about 50%. The lake lacks no water during high water penod. It is workable that this part of rain water does not enter the lake, and this will do good to the quality of the lake water. The following is a proposal for disposing this part of rainwvater. Table 4-4-38 Monthly Distribution of Non-point Pollution Load of the Nanhu Lake L_____ 11 2 3 4 5 16 7 8 19 0 II 12 allyar r-infall 37 45.5 537 87 0 146 234.1 1972 212.7 121.9 84.6 386 2 13290 ISS () 66.674 47.124 I 173 0.624 9532 1 165.395 676 664 80 546 24 159 0.001 543 76 S 9016 2455.064 COIX.,(t) 7.543 5.502 1S119 0 1O (0 117 394 62 013 8957 2 998 0 6 267 4 297 226.649 CODI) ( 43I.265 32.060 7.061 0.765 58 970 586 971 ! 20 118 50936 18004 0 0(2 36 279 25 351 1179783 IB}OO.(1) 14.044 11084 31357 0.581 179I0 1008 68 182 15.975 7.029 0.005 12221 9209 26965X rrt) ) 0(194 0.079 0033 0 019 0 112 0 425 02)) () 1( 00(57 ()()() 0085 0 0 WO I 366 R(1)-N ( 1.279 1.058 0 407 0 100 I 5C5 66 ON 4526 1 41X8 )7.5 ()()02 I 144 2912 1977; Plan I: Adjust thc trnk lincs in Qixin Road and Jiaoyu Road by maklilg use of the original pipelines and adding somc new pipe. clevate and deep-bury the trunk line in Taovuan Road so that the three trunk lines fornm latcral relation. Than add 400ni trunk line to the cnd of thc trunk line in Taovuan Road to connect it to Jingtou. so that rain water can be directly dischargcd inito thc Yongjiang River. At the same time build a controlling sluice to regulate thc anmountit of rain water entering the lake. Plan 2: Design the trunk line close to tihe west shore of the Nanhu Lake accordilg to tihc converging flow so that the tihree trunki lines can both draw rain water into sewage pipelines and lead waste water into the Nanhu Lake. The waste watcr intercepting coefficient does not necessarilv be ver\ highi. but thc crossing strcture ill be a bit complicated. As the Nanhu Lake will lack water after the waste water is intercepted. Plan I may be more practical. The 400ni trukik pipeline added can be used both \vavs: discharging rain water during high water period. and drawing water from the Yongjianig River into the Nanhu Lake in low water period. As the silt content in tile Yongjiang River is low, the plan is morc casily to bc 127 carried out. If the above plan is adopted. the project wvill be an environmental project as well as a civil enginecring project. For a wvater bodv sensitive to non-point sources pollution load like the Nanhu Lake, it can save time and monev to combine non-point sources control into the rain water pipeline project. It is inevitable to treat the Nanhu Lake soon ,if not in this project. After dredging of the lake's bottom clay to clear away its internal sources, the function of non-point controlling function of the rain xvater pipeline project will be outstanding. Good design in this can reduce the rate of silting of the Nanhu Lakc. thus reducing its future internal accumulation and release, playing a kev role in keeping fair wvater qualitv of the lake. At the same time the concentrations of organic matters and nutritious substances in the water body will be reduced to keep a good landscape and ecological environment. 2. Analvsis on the impact of the waste wvater project (I). Comparison of the two subtrunk waste wvatcr pipelines The two sections of waste water project are both located in Jiangnan District. That in Tinghong Road has a catchmcnt area of 13 Iha. belonging to the catchment of the Tingzichong Streawn the one in Baisha Avenue has a gathering arca of 369ha, belonging to the catchment of the Shuitangiang Stream. Together, the two gather wastc vater from an area of 500ha. tak}ing up 30% of the total area of 18.353km under the junrsdiction of Jiangnan District. As the project is planncd to bc carried out in 2001 aftcr the compiction of the project of joining the wvaste water trunkl line in liangbei District with Jiangnan wastc water treating plant, which discharges its trcated water into the Yongjiang River. So the project will bc a concrcte stcp to lead most waste water in Nanning City into the Yongjiang River after bcing treated in Jiangnan waste wvater trcating plant. As to the tmnnk line in Beisha Avcnue, it reduces the load ot the Slhuitangjiang Strcam upper the waste water treating plant while it gathers wastc '%ater The trunk line in Tinghong Road also cuts the load cntcring the Yong,iang Rivcr from tile Tingziciionig Stream wlhile gathiering waste water, thus improving the watcr qualitt at the outict of the Tingzachlong Stream. diminishing its threat to Lintic vater mill at the opposite shore Ficid monitorcd data showed the conccitrations of COD, BOD5 and NH3-N at the Tingzichong sectioln respectively rcached 500mg/L. 300mgiL and 7mgfL, indicating scrious pollution of thc water. If not trcatcd. not only the Tingzichong Strcam nwill rctain its bad nanic of a "foul ditch". but the polluted belt off its outict will kccp incrcasing to threaten Lintie water mill. Thereforc. the waste water projcct in Tinghonig Road is more urgcnt than thiat in Beislia Avenue. (2) Analysis on the amount of waste water gathercd The wvastc water trunkilhiuc in Tingihong Road receives waste water from niajor industrial polluting cntcrprises like Nanning Candy Papcr Mill. Nanning Silk Spinning Plant. and Na-nning Aluminum Plant. thc first two of which discharge a total waste water of 34 400n3/d (29 900mn3/d and 4 50013/d) According to thc dcsign. the maximum diamctcr of pipes in T'iigihong Road is d 700mm. hlic flow speed inside the pipclinc is 1.29m/s W\hen thc conccntration is 0.57. the dcsigned flow is 0.28nr3/s, which means 24 400mn3/d of waste "%atcr 128 passing through, less than the amount of the amount discharged by the two factories To receive all the waste water from the two factones, the filling rate has to reach 80%. Suppose waste water amount standard is 100m3/ha d. the amount of waste water is: a=131xl00=13 1OOm-'/d It turns out to be less than the designed water flow. So the flow in the original design is too low. not suitable for the waste water pipeline in Tinghon Road. Take 106 500m3/d as the amount of waste water in the catchment of the Tingzichong Stream, the concentrations of COD and BOD5 respectively 427ng/L and 184mg/L, the total amount of organic matters: COD 45.4755t/d BOD5 19.5960t/d But the total amount discharged by the first two factories COD 39.93t/d BOD 10. It/d It can be seen the amount discharged by the two factories takes up the major part of the pollution load of the Tinghzicheng Stream: COD -87.8% BODi 5 1.6 Thierefore. to lead the waste water from the two factories out of the Tingzichong Strcam 'ill have reniarkable environuilental benefit. So the designed flow of the waste water pipeline in Tinghong Road must be largcr than the amount of waste watcr discharged by the nto factorics. naml vcl: Q > 3 44nmi!s At least anotiler 0.6-1 0mn/s shiouild bc addcd if taking into considerationi of \aste water discharged by otlier factories and daily sewagc. There must be an increasing coefficient as the plan should consider the development to 201 5. According to the average increasinig rate, the amount of waste water in 201 5 shall incrcasc by 60% over thiat of 1995. But the dcsigned flow of waste water pipclinc in Tinghong Road can incrcase only 20-300% of the capacity. So thlis assessmeint suggcsts the designing institution make careful checkinig and dcsign To reccivc all thie \astc water from Nanning Candy Papcr Mill. the designed flow of the waste watcr pipclinie in Tlingloglig Road shotild at least bc 5.0m3/s. If part of the waste vater is to enter it, the polluted belt outside thc Tmlgzichong Strcam can bc improved The wastc water tnilk pipcline in Bcisha Avenue recci es waste water discharged by Nanninilg Clicmical Group. Nanninlg Tannery. Nanning Silk Spinniig Mill. Lysine factory, and Nanning Smielter. which together dischargc a total of 438 ()00m- /d of waste water. Take 369ha as the catchmieiiit area and I00ni-'/ha d as the waste watcr stanidard, the amount of wastc water is 36.) 000n-'id With thc maxiniiumil pipe diameter and a flo%\ speed of I .66m-'/s. and filling ratio ol() 62. the: flow vill be 56 570m3/d. That is to say, the designed flow is particle. but it still snmaller if considering thC development goal for the year 20 I 5. The total dadl\ sewagc in the 129 Shuitangjiang Stream is 57 000m3/d. To calculate from the ratio of constructed area. the dailv sewage of Baisha Avenue amounts to about 10 000m3/d Takc 1.57 as the industrial wvaste wvater increasing coefficient. the total amount of -aste mater is: Q - 1. 08 - 1. 57 x 4.38 = 79 600m31d Obviously, the present designed flow is a little too lo,. So the designed waste wvater flow of Baisha Avenue should be reconsidered.: The total designed waste water amount of the two subtrunk pipelines is Q = ( 13 1 + 369) 100 = 50 000m3/d The amount of waste water of the six major factories in the feasibility report is: QIndusiry = 78 200m3/d This shows a 50%' difference . If daily sewvage takes up 16% of the total amount of waste water, it amounts to: Qsecvagc = 14 900m3/d Then QTOtI1 QlJ,,s1 + Qswage =93 1 00m3/d The above statistics tak}es into considcration only the present condition, so the figure is smaller for the vear of 2015 Take 1.67 for the incrcasing speed, Ql.oa will be about: Q rorai (present) > 93 OOOm3/d Q-r..n (I201 5) > 1 6 000nim/d The flowv designed in the feasibility report has twice the diffcrence from the amount to appear in 2015. This assessimient suggests the construction designing department carefully analyze the spatial distribution of wastc vatcr to make thc design mcet the demand in one step in lighit of the overall plain of the city. The increasc of waste water in the futurc should be taken into considerationi to study thic possibility of adding m ore subtrink pipclines. As Tinglhong Road lics to thle middle sectioln of the right bank of thc Tingzicihong Strcam, the burying depth niust be big if all the %%aste water is to bc gathcrcd; if sonic subtrunk pipcline is to be addcd along the Tingzichonig Stream. it must have a drop ovcr thc trunk pipelinc. Therc is sonic flexibilitv as the subtrunik pipclinc is not the designatcd routc of dischiarging water. As the feasibility report provides no alternate plans for comparison. it cannot be said for surc that the dcsign is not practical (3). Analysis of the environmental impact of the two subtrunk waste water pipelincs Tnhc purposc to build thic waste water pipclinc network is to "bring thc planied waste wvater trunk pipeline network in Beijing District into the fullcst play by gathering industrial waste water discharged by laroc enterprises along the Tingzichotng Strcami iniJiangnan District, so as to gradually improvc the wvastc water gathcring system and tamne the deterioration of the receiving wvater body the Yongjiang Rivcr". According to the "Chart of Waste Watcr Pipeline Netwvork In Urban Areas of Nanning Citv", the two subtrunk pipclinies will involve 9 major pollution sources. of which 4 are along 130 Tinghong Road. and 5 along Baisha Avenue. The total amount of industrial waste water rcaches ovcr 78 200m;/d. the load of COD over 58.96t/d and that of BODs over 13.75t/d. The two pipelines involve water bodies of the Tingzichong Stream. the Nahong Stream (a tnbutarv of the Shuitangjiang Stream) and the Yongjiang River. The following is a discussion of its environmental impact on each wvater bodv. A. The impact on the Tingzichong Stream Tnc area along the Tingzichong Stream is concentrated with industrics of Nanning City. 1991 statistics showed the waste water in this area took up about 84%/0 of the citv's total wvaste water. Dailv sewage is relativel) little. So the major link in pollution control in this area is the control over industrial point sources. According to the city's drainage plan, the Shajin waste water pipeline will pass the left bank of the Tingzichong Stream. and the subtrunk pipelines in this project lies to the right bankl of the stream. gathering industrial point sources waste vater, This wvill greatly reduce the amount of waste water entering the Tingzichong Streamn. As there are more major pollution sources along the right bank than along the left bank, the aptitude of reduction wvill surpass 50%. The Tingzichong Stream is 7.55km long with a catchmcnt area of 10knm, and a gradient of 4.43/1 000. It has no diluting ability. and the guarantee ratc of the lovvest wvater level month P=90, meaning almost zero floxv. The water discharged into the Tingzichong Stream is basically wvaste wvater. So aftcr the completion of the trunk pipeline in TinihOlong Road. the amount of wvater of the Tingzichong wxill bc reduced bv half, but the pollution concentration of thic stream nvill not decrease much, retilainilig a little lowver than that of daily sewage. TIhc amount of water is comparatively larger in higih water period. with some diluting abilitv. Because of the waste water interception along Tinghonig Road. tihc now of wvaste wvatcr 'vill decreasc by half. that mcans doubling the runoff pollution ratio, so water quality will have sonIC imiprovenicrit. Accordinig to the average precipitation of JuLie o\cr the years 233.8mm, take 0.70) as tie real ninoff figure. the amount of rnoff is about 0( 6ni'ls. thcn the amount of wvater flow is 54 600nm-'/d. Under prcscnt load. the runoff pollution ratio can be raised from 0.5 to 1.0 aftcr the conpletion of the project of waste wvater intcrccption Vieved from thc situationi of both high water and low water periods, thc cnvironimlenital capacity of thc Tingzichionig Stream is very limited. It is possible to radically renovatc the Tingzichonig Strcam only after the completion of all wvaste water interceptioni project. But the completion of this projcct can nimct a major part of the dcmand. in fax or of the rcnovation of the T'ingzichonig Streanm As has been mcntionled bcfore. thc discharge from two miajor pollutcrs (Naanning Candv Paper Mill and silk spinililig plant) takes up 87.8X/O of the COD load and 5 1 6% of the BODi load of the Tingzichonig Strcam. Plus the inticrccption of othcr dail\ se"iagc. thc gathering rate of BOD, should reach about 80%. So the wvaste water interceptiotn project in Ting,hong Road equials to the functioni of a secondary waste watcr treating plant. In a word. thc subtrunk waste wvater subtrunk pipelincs in Tinghong Road will play a decisive role in improving thc water environment of the Tingzichoni Strcam . So the project 'I 8 should be built as soon as possible. B. Its impact on the environment of the Shuitangjiang Stream and the Nahong Stream The designed flowv of the waste wvater project in Baisha Avenue is 39 600m31d, accounting for 20% of the 183 OOOm'/d, the amount of waste w%ater in the Shuitangjiang Stream in 2015 according to the plan. Previous analvsis shows the designed flow is a little too low. If it is increased to 79 600m3/d, the ratio of waste w-ater gathered in the catchment of the Shuitangjiang Stream can increase to 43.49%. No matter wvhat the final designed flow will be. it should aim at the major industrial polluters and the amount of the wvaste water taken should account for over 60% of the total of the Shuitangjiang Stream catchment. Because there is no hydrological station on the Shuitangjiang Stream. anlogical flow was taken after the Yongjiang River catchment according to their area ratio The Shuitangjiang Strcam has an area of 581 1km2, Q (P=90%) = 170m '/s (the month of the lowest water level), the designed flowv of the Suitangjiang Stream in low water period: QlO,, (P=90%) = 1.34m3/s Qhigh(P=50%) = 24.29m3/1s (June) The amount of wvaste wvater designed in normal years Qvta (2000) = 13.04/8.64 = I.509m3/s Qvvaa (2015) = 18.3/8.64 = 2.1 18m3/s Thc runoff pollution ratio of the Shuitangjiang Stream in low water peiod a Q10s. (P=90%) / Qw,s,k (2000) = 0.89 U I Ql1" (P=90%) / Q"VJST (201 5) = 0.63 Aftcr the compiction of tihc project, the amount of wastc water entering thc Shuitangjiang Stream nwill dccrcase to; Original design: Q',,, (2000) (13.64-3.69) / 8.64 = 1.08 aI =1 34/1(08 = 1.24 Q,^,,a(20l5)=(l8.3-.96)/8.64=I .97 =1.34/1.69 = 0.79 Possible altcration in the design Qvax (2000) -( 13.04-7.96) I 8.64 = 0.588 a I = 2.28 QVast,. (2015) = ( 8.3-7 96) / 8.64 = 1. 197 a= 1. 12 So it can bc scn the completion of the project w.-ill greatly changc the runoff pollution ratio of the Shuitangjiang Strcami. Under the 200 load the original design vwill reduce thc concelntrationi of pollitioni by l nO froni the presenit level. thle altcred desigii can reducc as Illuch as 43%": unider the 2015 load, the figurcs arc about 9% and 23%. So the project has remark-able effect in improving the wvatcr quality of thc Shuitaigjianlg Stream undcr lo%% water condition. 1 32 I high w'ater period: the runoff pollution ratio is CtI Qhsil, I Qwaste (2000) = 1 6- 1 0 2 = / Qaste (2000)16 The runoff pollution ratio wvill increase after the completion of the project: Original: design = 22.45. cc 2 = 14.36 Possible altered design = 41.31 cc, = 20.29 It can thus be seen that the project will greatly increase the runoff pollution ratio of the Shuitangjiang Stream in high water period, restoring its wvater quality to that of Grade V surface water. It can be concluded that the proiect in Baisha Avenue will bear obvious effect in improving the quality of the water in the upper reach of Jiangnan waste water trcating plant up the Shuitangjiang Stream. C. Environmental impact on the Y'ongjiang River Both waste water pipeline netvork can gather waste water and change the location where point sources pollution enters the riv-r. The amount to be cut depends on the treating capacity of the waste w%ater treating plant. So thc waste water project provides favorable conditions for the water einvironment beloxv thc outlet of the Shuitangjiang Stream on the Yongjiang River. The waste water trunk pipeline in Baisha Avenue will not reduce the pollution load at the outiet of thc Shuiualigjiang Strcam. Thic load to be reduced depends on the treating capacity of the wvastc %ater treating plant. Tnhc %astce %ater project in Tinghong Road, howvevcr, will play a role in limiting and cuttinig thc polluted belt on thc Yongiang River outside the Tingzichionig Strcam becaLtsc it changes thic location for part of non-sourcc pollution to etiter the river Figg- 44-5 to 4-4-7 sho%% the analksis of thc possible rediuctioni of BOD5 load of major industrial polint sources along thc Tingzichong Stream aftcr thc comlieletioni of wvaste %%ater intcrcepting pipeiincs in Tinghlong Road The miaginitude contours of the polluted belts at the outlet of the Tingzichong Stream will rcduce bv alilf from the ones before the waste water intercepting projcct is built in Tinghong Road. Thc polluatd belts will shirink niuch to be shortcr, narrowecr and with less area. This is obviouslv good to thic cit\'s landscape The distance of the pollutc belts to the opposite bank is also increased. rcducinlg their thrcat to Lintic Water Mill. As the load of COD can be cut by N0%. its polHlIted bclts will be very small. ailiost zero in vertical spread. Besides. the amouLit of w%ater cntcring the Y'ongjiang R.ivcr fromi the Tingzichlonig Strcain will be greatl\ redticed. thius reducing the average pollItionI Concclntrationi at thc section of the Yongiiang Ris er at the l'Tingzichonti-Zlhupaichonig-Shuitaigjianig scgnicit . Take 170m3/s as thc ruioff flo\\. the load of COD, and BOD5 will rcspectively cut by 39.33t/d and 10.1 It/d. CODCr 2 68(mg/L 133I BOD,: 0.69mg/L The amount cut is to meet the standard of Grade III surface wvater, equivalent to contributing 17% of the wvater environmental capacity. Therefore the wvaste vater intercepting prolect in Tinghong Road will produce obvious environmental benefit for the segment of the Yongjiang River from the Tingzichong Stream to the Shuitangjiang Stream. 3 . Analhsis of the impact of the renovation of the sewage system in the old part of the city Thc purpose of the renovation of the sewage system in the old part of the city is to solve the senous pounding caused bv the narrowness of the pipelines through adding pipelines and desalt existing ones to improve the svstem. The principle is to design according to the designing flow of rain wvater, and the structure will follow the standard of waste water pipelincs. When wvaste water pipelines are added later. they will tum to specially receive rain water. The renovation of the sewage systcm can thus be looked upon as a process of changing combined flowv to separate flow, and possible environmental problems will arise from this process. Separate flow can reduce the diameter of waste water pipelines and their cost. reduce the scale and land used bv waste wvater treating plant . To cnlarge the diameters of the sevage system of thc old part of the city to servc as combined flow in the near future to lead into combined pipelincs in Nanhu through threc rain water trunk pipelines, of which Four sections of wvater discharging pipclines will cnter thc Nanhu Lake through the trunk rain watcr pipeline in Minzu Avcnue: those in \linsheng Road. Gonghc Road. Zhongshan Road. and Nanhuan Road. Onc section of the pipeline in Kangle Road will cnter the Nanhu Lake through the trunk rain watcr pipeline in Qixing Road-Jiaoou Road. One section of the pipelinic in Baoai Road will enter the Nanhu Lake througlh the trunk rain water pipeline in Taovuan Road. Those not leading to the Nanhu Lake include a section in the following: one leads to the Chaovang Strcam. onc lcads dircctlv to the Yongjiang River. and onc lcads to the Zhupaichong Strcam Wastc water from thosc pipelines not leading to the Nanhu Lakec will finally send the "astc \%ater into the Yongjiang Rivcr or the wastc water trcating plant. Tlcir cnvironmcntal impact till be reduced thoughi the gradual trcating of point sources. As thc waste watcr -will bc lcd to thc Nanhiu throughi a numbcr of pipclines. thc scparate flow of the renovation of thie scwage svstcii of the old part of the city vill improvc the \%atcr qualit\ of thc Nanihu Lakc to a certain cxtcnt. lihc ability to control non-point sources throughi rain water will dcterminc the gathcring ratio of non-point sources-pollution. It is thus recommcnded that the designing of thcsc pipclincs bc carried out aftcr the dctcrmination of thc rain watcr project conccrning thc Nanhu Lakc. th at is, to view it form thc anglc of tie o% crall control of non-point sources cntcring the NanhiLu Lakc to dccidc the rationality and ef1cctivcncss of the rain %%atcr pipclinc nctmxork in thc west sliorc of tilc Nanhliu Lake. And the concrctc designing paramictrs should bc decided on the baisi of this so as to reducc waste and add thc environmental bcncfit and 134 feasibility of the project. 4.5 Risk analysis 4.5. / Purpose = To analyze possibic accidents during the operation of thic project and thilr scope of impact so as to providc fecdback information.for the designing. 4.5.2 Ana/i'sis on the risk of the wtater discharge and treatmzeni systems (I) Breakl of river crossing pipelines The pipelincs arc usually stable as they are buried under the rivcr bed. So long as the pipes are of rational structurc, there will not be anv problem if detailed investigation of the geological conditions wvas done bceforchand and stnrct administration imposed during the construction. The ratc of risk is very low if every step is implemented according to the plan. In extraordinarv conditions like natural calamities of earthquake, the pipes may break. It mav have two levels of damage: * Light damage: the pipe cracks and waste water seeks out * Serious damage: the pipe breaks or bends and no waste water can be sent across the river In the first case, there will not be much damage to the project wvithin the designicd service life. Suppose 30% of the wastc water seeks out to pollute thc river, and onl' 70°%o is sent across the river, to lessen the pollution to mect thc designed demanids. the trcating level of that 70% of waste water can be raised during the low wvatcr season In case of scrious damage. all the %%astc watcr v ll cnter thc river to cause serious pollution. The1 righit cnd of the river crosstig pipe will be blocked b\ silt and thic left end can only havc some diversion functioni, so the desired function i\ill not be realizcd and certain pollution will appear. Btit thic probability of sUich occurrence is %er\ unlikely. and the rate of that in the low water seasonl is onlv one thiird of that. That is to sa\. %\lieii guarantec ratc P = 90'0. only 1/30 of thc river wvill bc affected. In most cases. thcrc %%ill be ceIouLghl ttmc to have thc pipe repaired or othcr preventive nicasurcs taken. The worst will onlk increase the length and width of the polluted belts. which will not causc catastrophic cffcct. But Lintic Water Mill will be directly affccted. Two preventive micasures can be considered. build an alternative ne\w atcer mill in the upper reaches to gradually rcplacc LinitiC Water Mill. or lay thc riv'cr crossing pipelinc at a locationi in the lower reacih to Lintic \Water Mill. (2) Accidents of the waste wvatcr treating s\ stemIl Failurc of thc machines or cut off of power supply .may stop the %%aste water trcating svsteni so waste wvater is dischargcd into the river %%itliout anv treatment As the waste wvater treating plant is located at outlet of thc ShUiztangi aain Stream in the lowver reachi of tihc city, suci accideint will not threaten the sourcc of the citWs dirinkiniig wvatcr. It is Pumiao In the down streamil tilat vill suffer. 13ut thic vatcr there has less strict environmental deilianid. and wvhen thc wvater reaches Puimiliao, which has a larger environmental capacity where w\aste water has becn 135 mixed to a certain degree. the impact will not be so serious. Besides, such accidcnts last only a short time and are easil\ treated. Risks of such accidents are of a vetrv low rate. 4.5.3 Analysis of risks during the dredging of bottom claot Possible risks during the dredging, transportation and refilling of the bottom clay are: a. Largc amounts of toxic gas is produced in dredging to poison construction work-ers or inhabitants nearbv. Gas masks should be provided beforehand as a preventive measurc. b. Bottom clay dredged may be washed back into the river by flood during storms. It is suggested dredging be done from October to April. of the follo\\ing year to keep away from the wet season. and bottom clay dug up should be transported away in time. c. Bottom clay may be dropped in the urban part of the city on the routes of transportation. So vehicles should be wvell lined and covered, or special garbage vehicles are to be used. d. The bank encircling the piled bottom clay may be damaged by flood, storm or earthquakc so that it is vashed into surrounding farmnland. Watcr overflow tunnels should be considered in the designing of such encircling banks. 4.6 Countermeasures to eliminate or ease up the unfavorable impact 4 6.1 Countermeasures to hliminate the unfavorable impact during constnrction I. Measures to prevent raised dust (I) Enforcc administration over the construction. The pnrnciple of protection while constmicting should be followed (2) Encircle the construction site with braided plastic fabrics to reduic the spread of raised dust and reducc its impact on nearby inhabitants and institutions. (3) Store onlv earth to be back filled on the site and transport a c! earthy to be cast avay in time Sprinkic watcr in finc %keather during thc drv season when carth is stored. loaded and transported. so as to keep the surface wet to reducc raised dust. (4) Closelv cover vehicles transporting construction matcrials lilkc cement. lime and construction garbage, to prevent raised dust and dropping (5) Shed the concrete mixer and lathcs site not far from each other it. It should be placed at places far from inhabitants. institutions or schools. Mist spray should be used when the mixer is in operation so as to rcduce raised dust and its impact on public hcalthi. 2. Measurcs to prevent and reduice construction noise (I) Strictly- abidc by rulcs anid regulations conccrning constriction sites promulgated by the city government of Nanning and rcgulations about noise. limit. Avoid using noise mak-ing machilies at noon or during night so as to rcducc the impact on inhabitants. (2) Try to concentrate the use as rushi wvork in optimized construction timlC of machincs that producc loud noisc. so as to limit the scope and shionrie thc timc of their noise impact 3. Prevcntion of traffic jams (I) Well plan and do a quick job of constructions to bc carried out in dowvntown areas to 136 heavv traffic routes. Temporary route for vehicles should be established and special personnel assigned to direct traffic, so as to prevent traffic jams. This can also reduce added of noise platoon. (2) Strengthen the administration, planning, and scheduling of the construction. Arrange good division of labor, and raisc efficiencv so as to shorten the construction period as much as possible. Back fill the earth and restorc roads in good time so as to reduce raised suit, noise. foui stiiells, and the scope of traffic jams. 4. Countermneasures for rcducing the unfavorable impact during the dredging of the Chaoyang Stream (I) Carnring out the dredging during the dry season (October to April) can cut off the extemal source of water so as to reduce water contained in the scdimcnt and shorten the time of drying. Tcmporarilv piled bottom clay should be transported in time so that it Nvill not be wvashed back into the river. (2) Dctailed calculation should be made as for the man power needed for the dredging, the amount of daily dredging job and the number of vehicles needed so as to optimize the plan for rapid work and timely transportation. For cxample. 100 people are to be employed for the digging of the segment from Youai Bridge to the outlet of the Dakeng Stream from October to April of the following y ear. If each person can dig Sni;d. thc total will reach 90,000m3. Machincs can be used in xvider segmcnts to add another 20.000m3 30 trucks (with loading capacity of 4t) will be enough to transport all the bottoml clay dug up if they take fivc round trips each day. (3) Bactericide can be spread in time to prevent the deterioration of %%ater quality and multiplyinig of flies and mosquitoes. Bleacinilig solutiotn can be sprinkled to destroy moleculcs that give out foul smclls and kill hamiful gemis at the same time (4) Gas miasks containing activated carbon fiber should be provided for constructionl workers to protect thein. Mcdical workers can be senit to the site durinig the dredging to gie-c timel1 medical aid In case it is necded (5) Water or cover-up material for solid waste matters (organilc higih polymcr mcmbrane) can bc sprinkleed on the surface of the scdiment piled up to prevent raised dust (6). Proper %%azis of piling the sediment cani reducC its impact on the environment. Tnhc kc liink in reduiciig the environmicnital impact durinig the piling and filling of bottom clay is to choosc proper wvays of piling. It is recomimieiinded to cncircle banks to be built around the pile. nic landfill site in Santang is situated on lo%%-i\ ing land surrotinded on three sides by hills. Not imluch eartlikxork is necdcd to miect the designed filling capacity. The base of the bank .can bc bedded with rows of fircvood. and the otitsidc of thc bank can use nylon bags filled with carti. Its insidc can usc loose carthi from nearb% slopcs to be rolled compact. Thc slope of a hill can be used as part of thc cicirclinig bank 400()Imi ' lJi(i0 of land wvithi 1. .m higih bank xvill be big cnotigih to pile 200.000mii 3 of sediment Scdieilcnlt containing Iiutich hcavyn metals should be piled In the ccitcr Seepage resistling niatcrial cant be usLd on the bottomi of the landfill to reduce 117 the seepage rate to below 10-7cm/s because the region is of sandv rock. Normal earth can be used to seal the top of the sediment pile, on wvhich trees can be planted. In this wvav the ecos-vstem can bc maintained and part of the investment retumed. The above measures can prevent surface runoff and seepage into the ground and reduce foul smells. But it must be pointed out that the construction aNill last a fairly long timc, (3 vears) during vhich uncovered pile of sediment may cause some runoff pollution and foul smells, so the construction should be speeded up and bottom clav be filled . mixed with some sandv clav and compressed timelv to reduce such pollution. 5. Countermeasures to treat pollution during the construction of waste water siphon pipeline Proper preparations should be made for the construction of the waste water siphon pipeline to shorten the construction period, such as building the towers beforehand, digging the tunnel during the low wvater season, and laying the pipeline from both banks to the middle of the rivcr in thc same time and laying the central pipe at last. When pipes are being laid in the rivcr. clear signs should be put up on the surface of the river and special personnel should be assigned to direct navigation After the pipes are sunk, back filling should be done immediatelv to speed up the progress of the construction. 4.6.2 Countermeasures to treat the impact dutring the operation of lite project I. Raise the designied scope of Jiangnan waste watcr treating plant Feasibilitv studies found out the completion of the Chaovang Stream projcct can lead about 258 OOm/d of waste water (1994 data) into Jiangnan waste water treating plant to be treated. Waste water pipelines in Tinghong Road and Baisha Avcnuc of thc scewagc svstem of the city can gather 78 200m;/d of wvastc water (1994 data) of the industrial region along the Tringzichiong Strcam and send it to be trcatcd in Jiangnan waste water trcating plant through waste water tnik pipelines in Jiangbei District. All together Jlangnain waste water trcating plant will be rcquired to trcat a total of 336 000'/d of waste watcr. But the designed capacitv of the first plase of tilat plant is only 260 (0;'/d.. SO it is suggested to raisc dcsigned scopc of Jiangnan waste water trcating plant. 2. Measures to reducc thc unfavorable impact of thc sludge produccd by the waste water treating plant (I) Inorganic sand cicared from railed and acration sedimentation basin Thc feasibility report of the project suggests that the inorganiic sand thus produccd can bc disposed at thc garbage filling grounid of the city. Scaling and coxering can reducc or prevcnt it fromi being dropped on its way of transportation. (2). Mud cakes of the dehydrated sludgc Mud cakes (containing 80% of w%-atcr) contain N, P and K can bc used as forest or non- recreation grecn field fertilizcr if proven to be safe by concenied departments. They should be Lised in hygiene land filling if proved harmful . and burying ground shiould be carefully chioscn. To prevent dropping and giving out foul smclls during the transportation, wvcll closed spccial vehicles are to be used. 13xt 3. Measures to reduce the noisc of the pumping station The designed capacity of the Dakengkou pumping station is 6.5m3/s with a lifting height of 7m. Shock absorbing measures should be taken to reduce the impact of noise on surrounding inhabitants. 4. Countermeasures to treat pollution of the project of water se-wer and conduit (I) Raise the designed flow of waste water pipelines in Hongting Road and Baisha Avenue Feasibilitv studies sho%v that the pipes to be used in the two locations are respectively d600-d700mm and d600-d900mm. As the point sources industrial waste water dischareed in the industrial region along the Tingzichong Stream is of large amount. the designed flow should be raised to meet the need. (2) Consider the design of the rain water trunk- pipelines around the Nanhu Lakee tog-ether wvith the cut of non-point sources, so as to produce benefit for civil engineering, environmental protection and fold prevention. A. Control the amount of rain water entering the Nanhu Lake in the initial stage of the first stormn after the drv season. B. Strengthen the treating and administration over the Nanhu lake. to restore the ecosy stem of its water body and around its shore. Raise waste water interception. absorption and clearing capacity. C. If possible. change the design of the direction of the flow of rain water entering the Nanhu Lake to lead it into the oYronijiang River. If the lake lacks water, water can be drawn from the Yongjiangy river to repienlish it so as to prevent the eutrophication of the lake. 139 5. Alternate Plans This assessment of the Chaoyang Stream Comprehensivc Treating Project was worked out by the Beijing Municipal Engineenrng Designing and Research Institute on the bases of comprehensive and careful analvsis on the scale and service range of the proposed project, the social, economic situations of the Nanning City and conditions for the construction of the projcct and the removal involved. The followving altemate plans are for further and more extensive studies and comparison. Plan I To lav waste water intercepting pipelines from the heavy-duty machine building factory southwvards along both banks of the Chaovang Stream within the scope of the plan, and lead its water to be emptied into the Yongjiang River at the outlet of the Chaoyang Strearn. Waste water in the pipeline along the nrght bank will flow into the pipeline along the left bankl after receivine waste water from the interccpting pipelines along the Erk-eng Strean, then be led to Langdong %-.aste water treating plant through the pumping station at the outlet of the Dakeng Strearn, and pipelines along Binjiang Road, Mingsheng Road. and Dongge Road. Plan 2 To lay the waste water intercepting trunk pipeline to the north of Youai Bridge within the planned scope along Beihu Road, Xitian Road. No. I and No 2 Roads to the east of the raillway The trunk pipeline dowm Youai Bridge connecting the pumping station and the trunk pipeiine along Donggc Road v.ill have the samc location and direction as Plan 1. Waste water is fafnm led to bc treated in Langdong wastc vater treating plant Plan 3 To lay thie vaste water intercepting trunk pipelinc to the north of Zhonghua Road along Beihu Road. Anji Road, Xiuan Road, No. I and No.2 Roads to the east of the railwav. Lead it to cross the l-lunan-Guangxi Railw-ay and then eastwvard along Zhonghua Road, collcct it with thc trunk pipelinc of Dongge Road through thc pumping station and pipcline in Yuanhu Road. Thc trunk pipelines to the south of Zlhongliua load in thc lower reachcs of the Chaovang Strcanm %%ill bc of the samc locationl and dircction as Plan I Only to be led to Langdong waste Water trcatine. plaint aftcr receiving waste wvater from thic upper rcacih of the Chaovang Strcam at thc cross of Yuanhu Road and Dongce Road. Plan 4 The location and direction of the trunk pipclines up thc outlets of the Dakecng Strcam in thc lowcr reach of the Chaovang Strcam. and the location of thc pumping station at thc outlet of thc Dakeng Strcam arc the samc as Plan 2. only waste wvatcr from thc Xixiang Pond will be led into the trun[k pipeline alotig the right bank- of thc Erkeng Strcam, then afler crossing the Chaovang Stream. to bc led thirough the trunk pipeline along thc left bank of tile Cliaovanig Strcam. lifted by the puniping station to be lcd across the Yong iang Rivcr. The trunk waste vater pipelinc in Jiangbei Distnct will be conncctcd to Jiatignan waste water treatilg plant throughE trnik pipelbies along \iangnani Road. Fujian Road and Tingjiang Road. Plan S The locationi and direction of thc tnmlk pipelines up the outlet of the Dakeng tream in the lower reach of the Chaoyang Stream. and the location of the pumping station at the outlct of thc Dakeng Streamii are the samc as Plain 2. only the waste wvatcr is led southward to cross the Yongjiang Rzxcr. The trunik pipeline in Jiangbci District is to be laid nsidc along the dike. 1401 through the Tingzichong Stream and Tingjiang Road to enter Jiangnan waste wvater treating plant. 5.1 Alternate plan for the waste water intercepting system on the Caoyang Stream Four alternate plans are put forwvard based on the characteristics of waste water discharging in Nanning City and its trcatiig plan 1 Alternatc Plans for Waste Water Intercepting Project and Comparison between them Plan 1: Merits: 1. Waste water pipelines wilI be laid along low\-lying land so that fund can be reduced: 2. Waste wvater from both banks can be intercepted at the same time: 3. Waste vater at Daklengkou can be lifted up to the Yongjiang River by pumping for the first stage, so the construction can be carried out in different stages. Demerits I. The construction of the %%astc water intercepting sy stem must be carnred out at the samc time with the trcating of the Chaoyang Stream; 2. The amotint of removal is large and the cost high; 3. Cost for the construction and operation of the pumping station is high. 4. Wastc water trunk pipeline along Dongge Road is ver long and the road is a busy traffic tuink line in thc city. %hich demanids a large invcstmcint and the conistructioln is verV difficult: - The location of the %"astc wvater treating plant is not ideal Strict demands will be set for wvatcr to be discharged into the Zhupaichionig Strcam. Plan 2. lcrits_ I .The construction of thi %vaste water trunik line and that of thc project of tihe treating of the river bed of the Cliao' ang Strcam will be carried out indepcndentl\ or in differe nt stages: 2 The amount to be rcmoxed is comparativcly smialler and thc cost lowver. . The pipclincs to be laid are along planned roads so that the amounit of removal w-ill be reduccd and the constructionl can be carried out at tic samc time \xitli other miunicipal cnginicering iteiis to save time and cost; 4 Thc trnkii linc to the upper strcanis of Youai Bridge is shorter: '.Wastc water can be lifted into thic Yongjiang River from DakecngkouL by pumpilg, so thc construiction can be arrangtd by stage. Dcmierits I 13rancli lincs niust bc added oni the cxistinig waste \\ater interccptinig system to achieve total interceptiol. 141 2. Roads %%ill have to be broken for the construction. and as a result, traffic will bc affected. 3. Cost for the construction and operation of the pumping station is high, 4. Waste water trunk pipeline along Dongge Road is very long and the road is a busy traffic trunk line in the citv, xvhich demands a large investment and the construction is verv difficult: 5. The location of the waste wvater treating plant is not ideal. Strict demands will bc set for water to be discharged into the Zhupaichong Strcam. Plan 3 Merits: I. The construction of the waste water trunk line and that of the project of the treating of the river bed of the Chaoyang Stream wVill be carried out independently or in differcnt stages; 2. The amount to be removed is comparativelv smaller and the cost lower; 3. The pipelines to be laid are along planned roads so that the amount of removal will bc reduced and the construction can be carried out at the same time With other municipal engineering items to save time and cost: 4. The waste water trunk line in the upper reaches of the Chaoyang Stream is shorter. Demerits I. Branch lines must be added on the existing wvaste water intercepting system to achieve total interccption; 2. Roads will have to be brokcn for the construction. and as a result, traffic will be affected. 3. Two pumping stations with high lifting capacity must be built. 'vhich -will cost a lot; 4. Wastc wvater trunk pipeline along Donggc Road is very long and the road is a busy traffic trnk linc in thic city. which dciiands a largc investment and thc constnmction is verv difficult. Tihc location of the waste water trcating plant is not ideal. Strict demalids will be set for water to be discharged into thc Zhupaichionig Strcam. 6. The construction of wastc water trnk linc in the uppcr rcaches of the Chaovang Strcan and that alone Dongge Road must bc carricd out at thic samc timc. Plan 4: Merits: I. Thc construction of thc waste water trunk linc and that of the projcct of thc trcating of thc rivcr bed of thc Chaoyang Stream will be carricd out independently or in different stages. 2. The amount to bc removcd is comparatively smaller and the cost lowecr: 3. ThliC pipelines to bc laid arc along planned roads so that the amiounit of removal will be reduccd and the construction can be carried out at the samc time with other mtinicipal engiincrinig itens to save tim:e and cost. 4. The trink line to the uppcr streams of Youai Bridge is shortcr: 5. Waste water can be lifted into the Yongjiang River from Dakenigkou by puimpinig. so the constriction can be arranged by stage: 142 6. The lifting height of the pumping station is lower and thus cost lcss: 7. Waste water will be led to Jiangnan. This agrees with the ovcrall plan of the citv; 8. Provides conditions for gathering waste water in other districts; 9. The location of the liangnan wastc water treating plant is ideal, favorable for building the plant in diffcrcnt stages. Demerits I. Brancih lines must be added on the existing waste water interccpting system to achievc total interception; 2. Roads will have to bc broken for the construction. and as a result, traffic will be affccted. 3. It imposes as a fairly hard task and costs a lot to lay niver crossing waste pipelines 4, Thc river-crossing pipelines serve a larger area so the construction cannot be divided into too many stages. As the sections of construction are large. more investment is necdcd all in one time and it is fairiv difficult to carry out the construction. ;. Large scale of the pumping station wvill require much inVestment; 6. Part of the pipeline will pass throughi Jiangnan Road. a trunk road of traffic. The pipeline is to be buried very deep in certain places and that rcquires a larger amount of rcmoval; 7. Treated wvater is finally discharged in the lower reaches. favorable for the protection of water source of the citv Plan 5 (recommended plan) Merits: 1. Tll construction of the sxastc water trunk line and that of thle project of the treating of the river bed of thc Chaovang Stream will bc carried out iidcpcidcintlx or in different stages. 2 Tlic amount to be removed is comparatively smaller and thc cost lower; . ilic pipelinies to be laid are along planned roads so that the amiounit of removal %%ill bc reduccd and the construction can be carried out at the samc timic withi othcr municipal engincering itcms to save timc and cost, 4. Thc trunlk liic to the upper strcams of Youai Bridge is shorter. zi Waste water can be lifted imto the Yongjiang River from Dakeingkou by pumping. so the construction can be arranged by stagc; 6 Waste water pipeline w.-ll be buried along the dike of tilc rivcr aftcr it crosses the ri\er. so tihat thc amounit of rcmoval rcquircd is small and there '\on't be much impact on traffic. The cost of operation and admlinistration will also bc lo%%. 7 Waste water %\ill bc led to Jiangiian. This agrees ,vith thc overall plan of the city. 8. Providcs conditions for gathering wastc water in other districts' 9 Thic location of thc lianginan waste water treating plant is ideal. favorable for building plant in different stages. 14. Demerits l. Branch lines must be added on the existing waste Nvater intercepting system to achieve total interception: 2. Roads will have to be broken for the construction, and as a result. traffic vill be affected.. 3. Cost for the construction and operation of the pumping station is high; 4. Waste water trunk pipeline along Dongge Road is ver lone and the road is a busv traffic trunk line in the cit,. which demands a largc investment and the construction is very difficult; 5. The location of the waste water treating plant is not ideal. Strict demands will be set for wvater to be discharged into the Zhupaichong Stream.; 6. Treated ivater is finally discharged into the lower reach of the river. favorabie for the protection of the city's water source. See Table 5-i-I for the comparison of the investment required. the cost of the removal involved, and the cost for power to be used by the pumping station. Table 5-1-1 Investment, Cost of Removal, and Cost of Power for tihe Pumping Station of Different Plans Planl tnvCstmenct1 Rcqutred Fee lbr Iketiloval Ltilipinit Station 10%ianila Iy'taiz uatn/a 11'1 10t1U yuantti/a 1(1' taU plan I 11115 175 5 pIlian 2 1 06(2 175 5 plan T S-4 529 5 plait 4. I l 320 2(Hl( 94.5 plan 5 I 1077 "X36 . 95 Note * Ilic draninge area ot Plans 1. 2. and; is 14knv. thalt ol Pllanis 4 and i is 5S ;Skn *When the pipxltne is to be laid alone roads or at sectiont otite ri-er vvh!; atre ready- niciided in the city's overall ilan. no lee t'or removal is considered Basecd on the cost-benefit analhsis. marks from I to 5 % ere given to the diffcrcnt altcmate plans. The onc wvith the least benefit or the most cost was givcn I point and the reversal. that is. the one with tihe bcst betiefit or the Iast cost %%as givcn 5 points Sec Table 5-I -3 for the resuits l 44 Table 5-1-2 Assessment Points of the Cost-benefit Analysis of the Plans Plan I 2 3 4 s Investmient for capital constniction 4 4 5 5 5 Land requisition and removal 3 4 4 4 4 l ocationi of piplinie to be buried 4 4 4 5 Location ol thle waste water treatin.g plant 4 4 4 5 5 IDearee ot diflicult for construction 2 2 2 3 Operation cost of the pumiiping station S 3 2 5 5 Conveiienice for constructioni in stages 2 4 2 5 5 Elvirorniental belnfit 3 3 5 5 rotall 25 29 25 36 38 As far as the protection of the water body of the Yongjiang River is concerned, the key issue of the five plans is wvhether the waste water from the drainage area of the Chaovang Strearn and the Erkeng Streanm should be discharged in the upper reach of the Zhupaichong Streanm or at the outlet of the Shluitangjiang Stream. In this respect. Plans 1. 2. and 3 are of one t\pc and Plans 4 and 5 another. The demerits of Plans 1. 2, and 3 are. First of all, if the tail water is to be discharged into the upper reach of the Zhupaichong Stream. thie water quality of the Zhupaichong Stream nwill not meet the standard required by its function. The following is an analyze on how% the water quality of the Zhupaichionig Siream can be made to meet the standard required for its function. The present functionl of the Zhupaichionig Stream is to receivc Waste water. Its water shiould ImlCet the standard of Grade V of surface w%ater according to the long temi plan. Bccause tihe Langdong waste water tre-ating plant is located at about 7 OkIii up the outiet of thL Zliupaichiotig Stream on the Yongjiang River. it v"ill bring unfavorable effcct to the realization of its long tenn function for tilc tail water of tEie waste water treating plant to be discharged into the Zhupaichionig Stream. According to thc data collccted by Nanning City Enviroiinieintal Monitoring Station. main pollutants discharged into thc Zhupaichong Stream in 1992 were those listed pl Tablc 5-1-4. Table 5 a-1-3 ain Pollutants Discharged into the Zhupaiclion Streanm Unlt: inl. l'olluitanlit Average M.axiliuti Minimu C(o) I.-( 99 199 17 53 07 130D,) 453(3 60( 38 20 34 As there is ccrtain influence from non-potit sources in the higih water season. the situationi of the lo\% %%atcr season was considered In calculating ho\ mucih lpollutants should be remo\ed froml its 1992 load so that its water w%ill rcach the standard of Grade V of surface vwater. Thie removing rate is 145 rCOD= I - 25 - 86.8; 7/0D =I - I0 = 834 189.78 60.38 It can bc secn that it would bc prettv hard for the water of the Zhupaichong Stream to meet thc standard for Grade V water even with level 2 treatmcnt. And the values monitored is the result alrcady aftcr certain degradation. In March 1992. the runoff rate w-as not P=90% bout around 50%. That is to sav, the watcr flow will be lcss than the 1992 one--once in everv two years. Conditions of Plans 1, 2, and 3 will not enable the water quality of the Zhupaichong Stream to reach the standard for Grade V water. Possible solutions include: 1. Waste water intercepted along the Zhupaichong Stream is directly discharged into the Yongjiang River with or without treatment ( may include treated from Langdong waste water treating plant). 2. To wash the pollution in its upper reach by drawing water from the Yongjiang River Yongjiang - ,---- Nanhu * Zhupaichong . Yongjiang (Langdong) The cost of the pipclines for the two segments is not high. but the amount of watcr is large and the cost of operation will be high. 3. Abandon Plans 1. 2. or 3, and adopt the recommended plan to lead waste water across the river. 4. Waste %%atcr intercepted along the Zhupaichong Stream is directly discharged into the Yongjiang Rivcr The Zhupaicihong Stream may bc reduccd to a dry ditch during thc dry season When water can bc dravn from the Yongjiang River for the sake of the landscape and irrigation. and thei method discusscd in section 2 above can be used or is treatcd in the samc wav with the Chaoyang Strcam. Thcse solutions can 'improvc the watcr qualitv of thc Zhupaichong Strcam. But thcrc is no advantagc comparcd withi the recommcnded plan if the vaste water from the Chaoyang Strcam is rcceivcd. Secondly. Tablc -- I- I shoxvs the cost of operation of the thirec alternate plans is 1 .85-5.6 timcs that of the recommended plan and there is no economic advantage either. If vaste \\ater is dischargcd into the Yongjiang River througli thc Zhupaicliong Stream. which is iicar the downtoown part of Nanning City. it will have apparent impact on thc landscape of the city. especially when thc citv undergoes further developilicnt. So none of thc alternate plans is economical as compared wvith thc plan reconmiended in improving thc city's environiment. Plan 4 is similar to the plan recomimiended cxccpt that it requircs thc trunk wastc water pipclinc to go through thc central part of the city aftcr crossig the river. thtis involving a larger constnmction area and increasing the amiounit of rcmoval. It is not as good as the rccommcndcd plan in this respect. Thc four alternate planis are not so good as Plan 5 in the investmcnt required and the 146 degree of difficulty of the construction- According to Plan 5 the tail water finally discharged by the waste water treating plant xvili be far from the cit-, favorable for the protection of the city's water source, having apparent environeiental advantage over that of the altemate plans. So Plan 5 is the optional choicc. S.2 Alternate plansfor thie treating of the water waY' of the Chaoi'ang Stream Two alternate plans were provided by the designing institution. Sce Table 5-2-1 for details. Table 5-2-1 Comparison of Alternate Plans for the Treatment of the Water Way of the Chaoyang Stream Item Plan I Plani 2 Plan 3 (Open tununel) (Covered tununel) (Combinedi Investmilent (I0' vuan) 152 50 21586 17439 ReImoval cost(104 yitan) 10703 4671 6512 Lanld required (ha) 26.13 11.36 17 99 Landscape twater surface (lia) I 314 5 1; Green field (la) 12.99 6 26 Flood detention capactlv ( 104i') 65 76 38 6 62 S6 IFlood drainini capacity of the pumipnin statioii n im'si 16 27 17 WVater supplenient=ofthe punping station (m (149 0 42 Cost of power Flood drainitn | 6 91 27 22 X 29 watcr 9 .2 3 07 upl1)I)ICi11 t:11_ Numiilber ol brieh:s to le reutltil _ 2 Number of sltuice: gates to be added . I 2 Thc folloxing is a comparison of thc conditions required by tihe thrce plans and thcir cinvironmental social bcnefit 1. Conditions for removal Plan 1: A largc arca %x%ll havc to be removed but somic of the pemianicit buLidinigs canilot be deimiolishicd and this x%-ill causc somc difficultv for the constructioni. and the deimiolishing of sonic old bridges xxill affcct cit% traffic Plan 2: Thc area to bc rciloved is the smallest and the impact on tmffic is also the Icast. Plan 3: The range of reimioval is the samc withi that of Plan 2 Up Youai Bridge. but larger from Youai Bridgc to Dakncilkou. BUt compared with Pllanl 2. It is less difficult for the construction and thc iilpact on traffic is smaller. 2. Conditions for carr iing out thc constrmction in stages 1.17 Plan 1: The whole waste wvater intercepting system cannot bc constructed in stages Plan 2: For a certain period of time no "vaste water interccpting pipcline is needed except at Dakengkou. The construction can be carried out in stages. Plan 3: The segment of open tunnel should be constructed at the same time wvith waste Water intercepting pipelines and it is impossible to separate them into stages. 3. Conditions for maintenance and administration Plan 1: Water in the tunnel must be periodically replaced and supplemented by the pumping station, whose secondary floor and recreational facilitics should be kept clean, and this needs much work and good management. Plan 2 1 Maintenance is easv and simple. Plan 3. Maintenance needed is similar to that of Plan I but the amount of wyork required is less. 4. Environmental social benefit Plan I Riverside parks can bc built and the natural ecosystem can be wvell maintained as the wvhole line offers much water surfacc for landscape. That will provide a recreational place for the people in the citv. The flood detention capacity is largc and the scale of the flood drainage pumping station is small. The arca of land usablc is the smallest. Plan 2: Landscape water surface is reduced and there will be sonic impact on the ecological environment. But green field or small sports ground can be built on the covered tunnel. The flood detcntion capacity is the smallest. and the scale of thc flood drainage pumping station is the largcst and the arca of land usable is also the largcst. Plan 3 A riversidc park can be built in the segment from Youai Bridge to Dakengkou. T'he flood dctention capacity is fairly large. and comparatively speaking the scalc of the flood drainage purimpilig station is small while the area of land usable is less. 5. Protection of thc water sourcc of the CitV Plan I Therc will bc no pollution to thc river itscif or the Yongjiang River during the dr! season. However. there wvill bc some pollution caused bv overflow during thc wct season. Plan 2. Thc Yongjiang Rivc will suffcr from ccrtain dcgrees of pollution in thc wet scason but it can be diluted in normal conditions. Plan 3 The opCIl tunnel and the Yongjiang River will suffcr from ccrtain pollution durint the wet season. Comparison from the abovc aspects proves Plan 3 is the most ideal among thc threce plans from ovcrall consideration and thcir econiomtiic and environmental aspects 148 6. Analysis on the Benefit of the Chaoyang Stream Comprehensive Treating Project 6.1 Analysis on its social benefit 6 1. 1 Improve the city's environmental quzalitv so as to stimulate the economic development As the capital of Guangxi Autonomous region, Nanning City is its political. economic. scientific, educational and cultural center. But so far thcre is no good sewvage system in the city. The existing pipeline network is shared b! rain water and waste water, usually discharged into nearby natural water bodies-- tributaries of thic Yongjiang River such as the Chaoyang Stream. the Erkeng Stream. the Zhupaichong Stream. and the Tingzichong Stream. and finally discharged into the Yongjiang River itself Thcsc rivers arc scriously silted. The Chaoyang Strcam flowing through the central part of Nanning City is a small streamii. The area around Nanhu in the ceniter of the city. wihere major governmental departments of the Guangxi Autonomous Regioni and Nanning City are located besides numberiess economic. financial and commercial institutions. It is also a densely populated inhabitant quartcrs of the city There is also a serious problem of waterlogng. The Chaoyang Strcam coniprehictisitc treating project aimiis at renovating the Chaoyang Stream. throughl laying rain watcr pipthines. itrceptinig and treating \aste water that now directly flows into the Chaoyang Stream and other tributaries of the Yongl talg Ri%er. desilting and maintainiing existing pipclinc network. raising the capacit\ of the pipelinc network to gaither storm runoff. strengthening thc mainteniance of iiachines used in the pipeline nct\ork s%stcm. strengtheninig its administration. Improving the sewage systerm In the old part of the citt. solving the scrious problem of water logging. gatthcrinig w-astc water from major industnal pollutcrs along thc Tingzicliong Stream in J1iangnani. checking thc deterioratioll of the wvater qualitt of the Yongjiang River. and improving the cnvironnctital quality along thc rivers. The completioln of the project will effectively solve probilms like raised dust on finc days and muddy road on wet davs. dimiinish foul siiells of the ri%ers running thirough the city. thus Improving thc cnvironmncital quality of thic city both of its wvater bodies and thc atmosphere. 1. 2 Proiect the wtater souirce of/he/ ctt antd improve is quahl ' 'lTi existiing sewage pipelincs in Nanning City is 204km;n long, w\ith a disposal capacity of l14) 20.055 million t/a. of which 97.78 million t/a is of domestic waste water. Most wvaste water flows into the tributaries of the Yongjiang River and finally into the Yongjiang River itself without anv treatment, causing serious pollution. The xwater of the tributaries is very poor. looking black and giving out fouls smells, while the pollution of the Yongjiang River itself is already affecting the quality of water supplied by the tapping -water plants of the citv. There are four tap water mills in Nanning with a total water supplying capacity of' 594,OOOt/d. or 25.069 million t/a (1993), providing the city w'ith water for industrial usage and people's daily life. The aniount of waste water will sureIy increase along with the development of production and population increase. If the Chaoyang Stream is not treated and let its water flow into the Yongjiang River at the outlet of the Dakeng Stream. the quality of water drawn by Lintie Water Mill will be seriously deteriorated and the mill would even be out of function. The cost for water treating in other wzater mills %%ill also increase. Compared %%ith maintaining the present water mill. it will cost far more to build a new -water mill in the upper rcach of the Yongjiang Rivcr and then send the water to the city. Therefore, the Chaoyang Stream comprehensive treating project is effective both economically and environmentally. 6 1.3 .Strenrthen flood resisting copacitv of the cit,- Nanning City has been suffering from frequent and serious water logging, wvhich mav be caused bv back flow of water from the Yongjiang Rivcr dunng the flood season. or by choked flow bccause the tributaries cannot timclv drain the runoff wvhen thcrc arc storms. It wvill bc a great tlireat when external and intcrnal overflowl happen at the same time. To solve the problcm of water logging, flood prevcntinsg dlkcs w\crc begun to bc built along the banks of the Yongliang River in 1973. Two big floods happencd in 1985 and 1986. whcn the flood level reached 75 88m and 76.23m. Tihc dilkcs plaed an inportant role in resisting the flood Nanning suffcred another scrious flood in 1994 and the lost wvas cstimated to reach 200 miillion y'uan. Now therc are 281 km of drainage pipclincs in Nannine City. of which 37% arc small pipcs with d400mnim. Wxf S 400 x 400imm. And most of thiemn are conccntrated in the old part of the citv. wvorking ovcr thcir scrvice timc and out of rcpair for years. So they cannot effectively drain the -water. Watcr logging of diffcrcnt scalc will appear in the city when thcrc arc storms. sonic times as many as 27 places arc flooded. Many of the roads now don't'havc any drainage devicc and will turn muddv wvhen in wct weather, such part of Mingxiuxi Road. the cross of Guchicig Road and Donggc Road. and Zhonghua Road. nic pipclincs have not becn dcsilted for a long time because the lack of' manpoxver and finance . thltis reducilIg tileir drainage capacity. h'lle siltilng of thc rivers also add to the inabilitv of the cit\ in flood prevcntion and resistance. lic plaicd project of the renovation of the Chaovang Stream. thc project of' water rain pipcline net-work. and the projcct to renovate the pipeline network in thc old part of the city. as I 511 well as the desitling and maintenance of existing pipelines, the addition and maintenance of machines, all form an important part of the waste water treating system of the central and eastern part of the city of Nanning. Major system of separate flow of rain water and waste xvater will be established in concerned areas. The dredging of the lower reaches of the Chaoyang Stream, the enlarging of pipelines and disilting, all wvill greatly raise the city's capacity in flood detention and regulation. So the completion of the project will greatly raise the city's capacity of flood resisting 6.1.4 Promote the development of the citv and raise people's living standard The construction of the Chaoyang Stream comprehensive treating project includes the renovation of the Chaoyang Stream and the renovation of rain water and waste water pipeline network in the old part of the city. These construction and their later managing institutions will all undoubtedly provide many new job openings. The Chaovang Stream flows through the central part of the city. Its treatment will bring a beautiful environment for developing tertiary industrv, which w%ill also open up many new jobs. Not only will the local economy develop, but more foreign investment will be lured in to bear a positive impact on the production of the city and the enrichment of the people as well. For years and years people in Nanning have been suffering from water logging during the rainv season. Houses in low-lying places were flooded and furniture soaked in water. The inhabitants living in these places just could not live a normal life. Besides suffering economic losses, they were nervous for such occasions. Thc laving of rain watcr pipelines Will improve thc life quality of its part of inhabitants. 6.2 Analysis oii the economic benefit of the project 6.2.1 Financial analysis of thc pro&e'ct According to the feasibility rcport of the planned project, construction of the whoIe project will start in 1997 and be completed in 2001, requiring a total investment of 695.07 million yuan. Thc predictcd financial balance and cash flow of each year were calculated on the basis of a duration of 20 years (2002-2020). Take 7% for thc intcrest rate of loans from the World Bank, without considering the fund and intercst collected at home, the comnmitment fee for the World Bank (total loan of the project - expense of the loan for five years (at the rate of 10.75%) will reach 230 000 US dollars. Financial cashi flow table reveals that the financial basic carning rate based on water drainage projcct is 4%. The present net value of the project within thc calculating period is 2.5 million vuan. The internal carning rate is 4.18%. This means thc project is feasible financially. 'sI But as the input of the project is mainly from governmental investment, and 10 million yuan will have to be allotted every vear for civil engineering maintenance. the project will not assume sole responsibilitv for its ow n profits band losses in the real sense. If the fee charged for discharging waste vwater %%ill not be raised but remain at the present level of 0.06 yuan/m3, the internal earning rate of the project will be 2.3%. If the fee charged for discharging waste water wvill be raised to 0.27 yuan/m3 since 1997. the government need not put in any fund after the project is put into operation, the project NNill be equal. If the fee charged for discharging waste water will not be raised to 0.40yuan/m3 since 1997, the government need not put in any fund after the project is put into operation, the project %Vill have an internal earning rate of 4.14%, enough for its maintenrance and to spare. (I) Composition of the project The project consists of (D Rain water pipeline network, which includes 13 trunk pipelines wvith a total length of 32.5km; (D Waste water project, which includes two waste wvater pipelines with a total length of 4.15km; 0 The project of the renovation of pipelines in the old part of the city, which includes the renovation of 21 drainage pipelines with a total length of 10.8km and the construction of a water discharging pumping house; ( Maintenance of pipeline network, for which 12 vehicles will havc to be bought; 0 Desitling and maintenance of pipelines. The length of pipelin=s to be desilted is 28.3km wnith a total of 53 00Om3 of silt to be removed; ( Adding 405 rain water inlets and 180 checking wells. TIhe cost for the waste water intercepting trunk pipelines at both banks of the lower reach (from Youai Bridge to Dakengkou) of the Chaovang Strcamn, of the water wvav treatment and dredging of the lower reach (from Youai Bridgc to Dakengkou) and the middlc reach (from No.28 High School to Youai Bridgc) of the Chaoyang Strcam, for water supplement for landscapc. construction of the waste water lifting pumping station. the laving of rivcr crossing pipcline and waste water trunk pipclinc nctwvork in Jiangbei, and the construction of the wvastc wvatcr treating plant. Also included arc cxpenscs for land requisition. housc removal and othcr preparatory vork for the project as well as odd cxpenscs beforc and during the construction of the project. (2) Engineering cost Thc cost of civil cnginecring of the project was calculated according to the economic indcx of scwagc engineering items stipulated in the Handbook of the Budget and Economic Assessmcnt of Watcr Supply and Sewage Work-s witli rcfcrcncc to the budget of similar works completed or under construction. Prices used for calculating the amount of materials wvhich can be bought for ten thousand vuan were thosc provided in "Information of Construction in Nanning" readjusted with the markct prices in Nanning in 1995-1996, plus 5% indircct fces. Thc total investment nceded for the civil cnginecring of the projcct is about 695 million yuan. 152 Table 6-2-1 Estimation of Basic Cost of the Construction of the Project and its allotment Item Investment Yearl% Distnbution World Bank Loan Home Invesn1 t _(10 yuan) 1997 1998 1999 2000 2001 10 vuan . 10 ly% uan % waste water intercepting 10298 2550 2820 1490 1814 1624 5582.5 54.2 4715.5 458. project on Chaoyang Streamn river course treating project 13004 2327 1551 3650 273S 2738 8200.1 63.1 4803.9 36.9 on Chaovang Stream I I I Jiangnan waste water treating 1744 0 0 0 523 1221 1605.6 92.1 138.4 7.9 plant I rain pipeline projects 12806 2377 2468 3107 3397 1457 5252 4 1 7554 59 sewage pipeline projects 827 8 827 290 35 537 65 pipeline t;ransforming 2597 728 1296 573 954 37 1643 63 projects _ _ maintenance of equipmtetit i 164 738 426 1164 100 0 0 maintenance of pipeline 142 142 = 43 30 99 70 other 13558 2898 3353 4815 2494 3626 26.7 9932 73.3 toial 57304 10294 12397 13623 11540 9450 27881 48.7 29423 51.3 Fund for this projcct comcs from two sources: First, loan from the World Bank, used to import equipment and matcrial. invcstment for civil engineering, to pay foreign advisors, to pay for the expenses of conccrned pepsins going abroad. and to pav thc interest during the construction and commnitment fee. Seconid, charges on waste discharge collected by the Ninning City Govcrnment. fund for maintaining citv construction, fee for thc use of drainagc device and part of the land development fcc, uscd for the investment of the project (no interest), to buy loal produced matenals and othcr allocation equipment. ald to pay the fcc for inhabitanit resettlcment and house rcmoval. total (,0' 4tUan) _______________________________________ 1USS RMF3 =USS RMIB Total rundo :urcus 4058 33934 52541 69507 I World hank loans 4058 33934 33954 1 I I lard loan 2045 16967 30967 1.2 Sol ltian 2045 16867 35574 10967 2 H Iotn inve-stment 10000 35574 2.1 lumcipal maintenance and constniction fce e 7986 3000 2.2 Wisite water discliarte fcc 15000 7986 2.3 Newdv developled land 2588 15000 2.4 Support from regiioial govenmenit - '588 153 (3) Operational cost Operational cost refers to the expenses for the operation and maintenance of the water pumping stations and waste w%ater purnping stations. The cost of electricity fee is calculated according to the designed w-ater volume. Suppose the stains need to be, and the electricity for industrial use is 0.51 Svuan/khw, the electricity fee amounts to 5.46 million yuan a year. The budget for maintenance fee for sewage pipelines is 13 000yuan/km, as the project involves 52.8km, the total maintenance fee is 690 000yuan a year. * Take 95% of thc total investment as the capital assets of the project, and take 1.7% of the original value of the capital assets for capital repairs fund, it amounts to 11.23 million vuan a year. The total operational cost is 19.13 million yuan a year. * The total cost should also include the depreciation of fixed assistant the amortization of all expenses. The annual depreciation and amortization come to 24.82 million yuan all together. . Together, the above cost ad to a total of 43.95 mullion yuan a year. (4) Prediction on the income * Because of the characteristics of the project it is hard to determine who will be the beneficiary. As a municipal public project, its income mainly comes from waste water discharging fee. The present rate is only 0.06yuan/m3. It is suggested to raise it to 0. 12yuan/m' so that the construction unit will becomc a trulv independent economic entity instead of having to be supported by administrative allotment. The goal to be realized is to maintain the wvaste water svstem bv levying waste wvater discharging fee. - The amount of such fee charged will be determined by the figures recorded in all water metcrs in the citv. 50% of the fcc collectcd will be considercd as the income of this project. It is estimatcd that the amount in 2010 can rcach 20.65 million vuan. e Municipal maintcnancc and construction fee and the revenuc from newly developed land collected by the city govcrnmcnt will bc used as the key support for the projcct during its construction, thcreforc it is also counted as the incomc of this projcct. But aftcr the project is complctcd and put into opcration. the projcct i%ill dcpcnd solcly on the fee collccted for wvaste water dischargc and thc 1000 vuan of city construction maintenance fee. * It is hard for the project to maintain its financial balance during its construction and the initial stagc xvhen it is put into operation, so the projcct necds financial support from the citv anid rcgional governments. (5) Plan of the repayment . The internal part of the investment of the project is allotment from the government, which does not need to bc rcpaid. Thc loan from the World Bank will be rcpaid through- the depreciation of fixed assets and the amortization of othcr itcms. It is suggcsted that the deficiency will be madc up by profits of the planned waste wvater company. . To simplifv the calculation. 7.0% is taken as the annual rate of interest of the loan and 25 ycars--including 5 years as the gracc pcriod--as the period of thc repayment. (6)Anal% sis ovcr its sensitiveness, 154 The large amount investment of the project exerts great influence on its financial situation. Comparatively speaking, the vanration of maintenance fee and operational cost will have only secondary influence. See Table 6-2-3 for the details of the financial sensitiveness of the project. Table 6-2-3 An alysis of the P oject's Financial Sensitiveness Itemi Variation (%) Benefit Item variation (%) Bencfit Investment -20% 5.74 Mainteance -20% 4.29 -10% 4.95 -10% 4.23 forecast 4.18 forecast 4.18 +10% 3.42 +10% 4.12 +20% 2.70 +20% 4.06 Used -water fee 0.24 11.85 Operation -20% 4.96 yttan/mn 0.18 8.54 -10% 4.57 0.12 4.32 forecast 4.18 0.06 -2.01 +10% 3.77 10.03 -7.75 +20% 3.35 6.2.2 Analysis of the national cconomy of the project Thc projcct will bring a lot of indirect benefit that can hardly be put into statistics. The following is a rough estimation of somc of the external benefit as a resiult of thc protection of wvater source, lowering the cost of water supplV, the increase of the pricc of land whosc environimcnt will bc improved, flood prevcntion capability of thc project, and the project's influcicc on the development of the city's industry. (I) Raise the citv's flood rcsisting capacitv * Nanning City is located in the subtropical oceanic climate zonc wherc thc rainfall is abundant, avcraging 1 300 mm/a ovcr the years, with a maximum of 1 970.6 mm/a. As storms arc frequent in summer, part of the city oftcn suffers from water logging. Thc dcpth of water may rcach 0.4-O.8m. causing traffic jam besides flooding houscs. . Data reveal tilat 27 places often suffcr from serious wvater logging in Nanning City. which arc mostlv in the downtown part involving major strects and with a densc population See Table 6-2-5 for the details. * Incompictc statistics reveals that the lost caused by water logging reached 39.18 millioni vuan/a. Sec Tablc 6-2-4 for thc concrcte figures. 155 Table 6-24 Economic Lost caused by Water Logging in Nannino Citv No. Item Unit Number yuanlm2 lost (10 vuan) I Cleaning and disaffection of the flooding house m2 17500000 100 1750 2 Cleaning of pipeline km 250 20000 500 3 Flood drainage and emergency treatment 168 4 Other indirect lost E [00 total _3918 Notes: l. Water logging averages ten times a year, 2. the flooded area average [.75km2, with 25km of pipelines submerged; 3. Each time 150 persons are needed for flood drainage and emergency treatuent, w%ith 60 vehicles and 20 machines and 100 000yuan worti of materials. Table 62-5 Major Water Lo 2ing in Nanning City No. Location Area Depth Affected No. Location Area Depth Affected (- km2) (m) population (kmt) (ni) Population I Mingzhudadao 0.05 0.8 1500 15 Kangleu 0.07 0.6 700 2 Donggelu 0.05 0.6 500 16 Mingzhulu 0.26 0.5 2600 3 Tangshanlu 0.03 0.6 300 17 Mingsheniu 0.03 0.4 300 4 ionvanndonglu 0.03 0.5 300 18 Gaofenglu 0.02 0.4 200 -5 Hiiogvangxilu west 0.05 0..4 3000 19 Jinanlu 0.02 0.5 200 6 llonevangxilu cast 0.02 0.4 3000 20 Zhaovanglu 0.03 0.4 300 7 Minxiuxilu 0.05 0.4 soo 21 Shizhoulu 0.02 0 4 200 S Mingxiuzhonglu 0.03 0.5 300 22 liuadonglu 0.03 0.4 300 9 Xioulinghlt 0 03 0 5 300 23 Zhunhualu 0.05 0.4 500 It) B3eibuubilu 0.27 0.6 2700 24 Anningxiaoxiclu 0.07 0.8 700 HI Jiangiianilu 0.17 0.6 1700 25 Youailtu 0.04 0.6 400 12 lianignanilu 0.17 0.6 1700 26 Guenhelu 0.02 0.4 200 13 Taovuanilu 0.03 0.6 300 27 Wuvilu 0.06 0.6 600 14 Qixinitu 0.10 0.6 1000 _ total 1.72 1 20200 Notes: I. The area and population influenced refer to those along the streets; 2. Tnis Lable does not include thc flood in the comnpounids or yards of institutions and inhabitant houses. (2) Protcct watcr sourccs and cconomization of thc cost of watcr supplied The existing vatcr plants in Nanning can hardly mect the watcr demand of the city. If a ncw water mill is to bc built in thc upper rcach of thc Yongjiang Rivcr (for cxamplc at Clienchun Villagc), the investment needed for its construction added with that of the pipelines to send water to the city, the cost will be much higher than maintaining cxisting water mills. Lintic Watcr Mill is locatcd in the lower rcach of the outlet of the Chaovang Stream, where thc water 156 is already polluted by the polluted belts in the Chaoyang Stream and the Erkeng Stream. The cost of medication and treating has been growing rapidlv. If the treating cost of each ton of vater increases by 0.1 cent/t, the 100 OOOt/d water supplied by Lintie Water Mill will need 100 yuan more. That means 36.5 million yuan/a. The development of Nanning's economy and increase of population will produce more xwaste water, wvhich. if not gathered and treated. ill deteriorate the water quality of water supplied by tap water mills. When the worst happens. somc of the mills will be out of use. Suppose the cost of wvater supplied rises to 0.5yuan/m' in the year of 2000, the present operation of existing wvater mill needs only 0.1 1vuang/m'. After 2000, the cost of added wvater supplied will be 365 x 50% x (0.50-0.15) = 5.1 1 million yuan/a. The completion of the project will maintain and improve the quality of wvater drawn by the water mills. (3) Protect the wvater quality of the Yongjiang River and raise industrial output value The environmental capacity of the Yongjiang River is limited. The goal of environmental protection of Nanning City is to maintain the water qualitv of the upper part of the Nanning segment of the Yongjiang River at Grade 11 and that of the lower part Grade III. To reach this goal, the total discharge of BOD5 must be controlled to be beloxv 40,OOOt/a. But according to the development plan of the city it is predictcd that the amount of BOD5 discharged by the year of 2000 will rcach 40,OOOt/a. If the load of BOD, entering the Yongjiang River is not treated and reduced, the cnvironmental goal will not be reached and the development of industry will be restrained. The industrial profit and tax of Nanning City was about 1.5 billion yuan in 1995. The estimated annual growing rate of industry is 15.4% from now to the xcar of 2000. 13% in 2001-2010. and 10% aftcr 2011. without considering the restrain of the cnvironmcnt. Withiout the proposed projcct, environmcnital restrain will sloNv the growth rate by 2%, that is. thc growing rate xvill be 12.74% in 2001-2010 and 9.8% after 2011. The lost thus prevented by ridding the environmental restrain on industrial growth can be accountcd as bcnefit of thc project (4) Improvc thic cnvironment and raise the valuc of land nhc project can radicallv improvc the cnvironment surrounding it and raise the valuc of the land. For examplc. the prcscnt land uscd for commcrcc and living houscs along the banks of thc scgment of the Chaovang Stream to be renovated to Grades 1-3. ThIC basic price of such land is listed in thc tablc. TNI)e G(irade: IA Gradc I B Grade 2 Giradc 4 Land Ior cotilllcrce 3750 V.UZ3JVIfl: 2580 *aai/ii- 1950 viyaiV/rn2 I1 20 yuaz/nV L.and for h1wine hou.ses H 135 Nua-tn/Hr1 1 135 juant/nz 885 vtianhil 680 vuanhw& Supposc the grade of thic land of lOOm wide along the banks of the 4.87km scgment of the 157 Chaoyang Stream to be renovated can rise for one grade, that is. the average price of land for commercial purposes rise by 922yuan/m2 and that for living housesr nse by 228yuan/m2, and suppose either takes up 50%. the average price rise can be 575yuan/m2. Takle 12% for the rate on interest for land investment, the added interest of the land %vilI be 69vuan/r& a year. This will bring a benefit of 4 870 x 100 x 2 x 69/10 000 = 67.2 million !yuan/a. And this vill bring benefit to the national econonm. Dymamic analvsis on the flow of fund of the above data revels that, when social discount rate is 12%, the net value of nation economy will rcach 29 02 million yuan, that means an internal benefit rate of 13.15%. 6.3 Analysis on its environmental benefit 6.3. 1 Benefit for environmental protection The Chaoyang Stream comprehensive treating project is a project that will improve the environental ecology, bencficial to people's health. The major benefit of the project is that it will solve the problems of foul smells, flood and water logging, from which the city has been suffering for many years. It wvill improve and renovate the sewvage system of the city, providing conditions for gathering and treating industrial waste water along the Tingzichong stream, so as to improve the environmental quality of the down town areas of the city and people's living conditions. Thc project can also alleviate the prcssure of the city's waste water on the Yongjiang River, remove the threat to Lintic Watcr Mill from pollution of the Yongjiang River. The amount of waste water gathered and treated by the project .,ill account for 40% of the city's total. That will greatly reduce the pollution load of the Yongjiang River and greatly improve its water environment. 6.3.2 Analvsis on cnvironmcntal economic cost-bencfit (I) Analysis on the environmental economic benefit As the projcct is a kcy cnvironmcntal protection project of Nanning City. its environmcntal invcstment is the major part of thc total investmcnt of the projcct. Table 6-3-1 Investment for the Drainage Engineering of Nanning City Environinciital Item Protcction Designing Capacitv Unit Investmcnt (I 04 yuan) Waste -ivatcr intcrccpting pipcline dl 650-d2OOO l.<)6Okm 4250 River course treating L=6.2,km 11064 waste wvatcr pumping station 2.7m31s 900 Sewage pipelinc 03200x2200inzn L=3.85kni 2348 Puniping station for waste uater treatin-g plant 4.Oin3/s 1744 In-glonglu scevcr d600-700mnm L.= Ikm 221 liatsadadao sewer d600-d90Otnm L.=3.1 5knm 606 Water scwcr and conduits 13 pipclines L=32.5km 12806 Modification of drainagc system in old urban 21 pipelines l.=10.km 2597 I)clisting pipelile 1.=28.3km voluc=53 000m3 1158 rental 33826 158 The total investment is 695.07 million yuan, of wvhich 367.94 million yuan is investment for environmental protection, taking up 53%. (2) Environmental impact of the project and countermeasures to be taken a. The construction of the project wvill destroy about 164 OOOm2 of road surface along road with a total length of 53.45km, which are conccntrated in the dow,ntown area. So that \\ill cause much inconvenience to traffic and people's life. This should be properly arranged and its administration strengthened. b. The total area of road surface to be broken reaches 164 OOOm2, with a digging depth of 1-2m. That involves large quantities of earthwork. The castawav earth piled along the roads w'ill (produce raised dust on fine days and mud on rainy days, bringing negative environrnental impact. So the job must be done in a very civilized way and the construction sites should be enclosed. c. It is better to send the rain water of the first storm of the wet season to the waste water treating plant to be treated and then discharged into the river, so as to reduce its pollution to the Yongjiang River. d. The waste water lifting pumping station is located in the central part of the city and so its noise will have negative acoustic impact on the environment if not properly designed.. Noise reduction and sound-proofing measures should be taken to reduce the negative impact to the minimum. c. It is suggested that the 0.2 million m3 of bottom clay from the dredging of the rive be transported to Santang filling site for hygiene burial. not discharged in Yanziling. f.. The waste water treating plant is located in Jiingnan District at the windward direction of tihe city. It is suggested that wide separating green belts be built around the plant and the citv civil construction be rationallv arranged so that not much atmospheric environmental impact will be caused. G. Watcr replcnislhing period should bc shortened to maintain the water quality and landscape during seasons when the wvater of the Chaoyang Strcani is of comparatively poor qualitv. i59 7. Plan for Environmental Administration and Environmental Monitoring 7.1 Setting up of environmental protection bodies 7.1.1 Aim and purpose To implements laws and rules and regulations about environrental protection, to see to the consistence of the envirorunental benefit, social benefit, and economic benefit of the project, to guarantee the effectiveness of polluted water and waste water treating, and to monitor the environmental quality of the project and its surrounding areas and its change of social economic factors so as to provide basis for environmental administration and overall planning of the city. 7.1.2 Organizational strncture and number of staff The department of environmental protection of the Chaoyang Stream Comprehensive Treating Project consists of twvo parts respectively in charge of environmnental administration and environmental monitoring. Special personnel from the Chaovang Stream Administration and the City Construction Developing Company will be assigned to be in charge of the environmental administration during the construction of the projcct. T'he fixed number of staff members will be 2-3 people. A water quality monitoring station will bc established in Jiangnan Waste Water Treating Plant, whose number of fixed staff members being 4-5 peopic. 7. 1.3 Functions of the environmental protection bodi 1. Environmental administration (1) To carry out laws and comply with standards of cnvironmcntal protection (2) To establish administrative rules and givc frequent chcck up (3) To wvork out environmcntal protcction plans and see to their implementation (4) To lead and organize environmental monitoring and cstablish data (5) To carry out environmcntal education and technical training so as to raise the qualitv of the staff (6) To cstablish rulcs and regulations on the discharge of pollutants and the operation of cnvironmental protection facilities: to coordinate with thc municipal cnvironmental protection bureau to answer questions raised by the public and tackIe involved problems; to check environmental protection work and compilc statistic matcrials. 2. Environmcntal monitoring (I) To work out monitoring plans and rules and regulations of the station (2) To carry out monitoring over the itcms required and compile forms for reporting statistics and write reports I 6 (3) To take part in the investigation over environmental accidents (4) To take part in environmental assessment (5) To take part in the investigation and tracing of social economic factors (6) To test, maintain, and repair instruments used for the monitoring to ensure their norrmal scrvice. 7.2 Measures for environmental administration 7.2.1 Environmental administration duiring the construction of the project 1. Aim: To prevent or reduce pollution caused bv the construction 2. Measures for environmental adrninistration (I) The institution that undertakes the project should take the overall responsibility for the environmental protection during the construction and see to it that it is done in every stage and by every department concerned; (2) Work out unified arrangement for the countermeasures to be taken. the order of the construction, and the fixing up of construction sites according to the requirements of environmental protection authorities and set in this assessment; (3) Construction teams are required to be responsible for the environmental protection and see to that the following environmental protection plan be carried out: A. Plan to treat construction noise Noisc pollution during the construction is mainlv caused by constructionl machines and vehicles. ThC standard sct in Rulxes and Regulation for Noise Pollution Prevention and 7'reatnient and Document GB12523-91 Noise Limit for Constnrction Sites Special attention should bc paid to the construction noisc at night. B. Plan to reduce raised dust of the bottom clay of the projects. Largc amount of sedimcnt has to be dug up from the projects and there may be droppings during the proccss to producc raised dust. The dredging and the transportation of thc bottom clav should be done in a civilizcd wav, and transportation vehicies should be well covered. 7.2.2 Environnental administration after the project is put into operation 1. Aim: To cnsure thc nomial operation of the project so as to meet the cnvironmcntal demands of the designing. 2. Measurcs for environmental administration (I) Unified administration over cnvironmental protection Environmcntal protcction should bc part of the overall administration ovcr the Chaoyang Stream and urban drainagc pipelines, and attcntion should be paid to the cnvironmcnit in every link of the administration. In this respcct it is lcd and supcrvised by the Naining Municipal Environmcntal Protcction Bureau. (2) Normal opcration of cnvironmcntal protcction facilities After the projcct is put into opcration, normal operation of the pumping station and the 161 waste water treating plant should be maintained. and strict responsibility system should be established. Operation record should be kept to see the designed requirements are met. 7.3 Environmental monitoring plan 7.3.1 Environmental monitoring during the constnrction of the project l. Aim: To check pollution like the noise during the construction and droppings of botton clay during the dredging and desilting and take timely measures for treatment. 2. Duration of monitoring The whole period of the construction of the project, with the laying of waste wvater pipelines and the transportation of the bottom clay from the Chaoyang Stream as key periods 3. Itemns to be monitored: Items to be monitored are the following considering the concrete situation of the project: (I) Noise: Equalized intensity of sound in dB(A) (2) The atrnosphere: TSP 4. Monitoring points Monitoring points during the construction should be selected in densely populated inhabitant quarters. The number and interval should be detcrmined according to the concrete situations. 7.3.2 Environmenial monitoring dzuring the operation of the project 1. Aim: To check- thc actual impact of the project and prevent pollution accidents, so as to provide scientific bascs for the cnvironmcnt of the Chaovang Stream and Nanning City. 2. Monitoring duration Tlhc kev factor to be considcred is the scasonal change in thc cffcctivcness of waste water treating. 3. Major items to bc monitorcd and monitoring frequcncy and position (I) Water quality of the Chaoyang Stream Monitoring should bc carricd out at the wvatcr quality monitoring section of the rivcr. Sce Table 7-3-I for items and monitoring frcquency. (2) Waste water The point to be monitored is thc outlct of the trcated watcr from the wastc watcr treating plant. Sec Table 7-3-1 for the items to be monitored and monitoring frcquency. Table 7-3-1 Items to Be Monitored and Monitoring Frequency Coatcut Location Items Monitored Frequency Water Quality of One sectioin respectively in its upper, BOD COID coli Onrcc a molitli Chaoyanig Strcam middlc and lower reaches Waste water Waste Water T reating Plant BOI) COD, coli, N, P Oncc a monti 162 7.3.3 Investmnent of the environmental monitoring plan It is suggested that the investment of environmental monitoring plan from project is 0.30 million (RMB). which is used for management and environmental monitoring of project during the operation. Certain amount of fund of monitoring should be arranged dunrng the operation of project. 7.3.4 Estimation of investment on monioring instrumnte and equipnent Tlhe institution that undertakes the project should take the overall responsibility for the environmental monitoring to pollutants discharge during the operation according to the requirements of national environmental management ruies. After the project is put into operation, the waste water treatment plant should set up lab of water analysis. It is necessary for monitoring instruments to be provided. See table 7-3-2 for suggested monitoring instruments. Table 7-3-2 Major Monitoring Instruments Instruments Unit Amount Investnent E Use Computer Bench I 3000(RM13) Data analysis Sample collector for wvater Benchi 2 5000(RMBi Sample of -ater Spcctropolarinmeter Bench I 3500(RMB) Analysis for organic and inorganic pollutanits Refngerator Beinch I 5000(RM131 Preservation samples Analysis balance( I/lOOI) Benich I I500(R000 1I Weiglht I)rying oven 13enchl I 3000MRI1 i Treating sample COI) analv,er Rench I 20000(RN1 i Meastirino COD Operatin.g desk of bacteria Benci I 25O0(RMNIA disintfection Small instnimcnts 5000(RMB3) 1 (i lass instniiicnts 4000(RMB3) Including itciems of infrastnmcturc like of experinment tables anid ventilation boxes, the total investmenit for instrumenet is about 0.6 million vuani 163 8. Public Participation Environmental problems are getting more and more serious globally along with the social development. and people's environmental sense has reached a new height so that they have a sense of responsibilitV for the protection of the environment. Public participation of this sort is not only an important mark in measuring a nation's sense of the environment but also a need for developing environmental protection and economy. 8.1 Aim and purpose The World BankL hopes that the assessment on the environmental impact of the project submitted to it will fullv reflect the views, suggestions, and demands of the communities and local non-governmental organizations which will be affected by the proposed project. News conferences, testament sessions, and expert advice soliciting meetings should be held so as to have a good understanding about the scope and extent of the social. environmental, and economic impact of the proposed project in order to provide a reliable, sound, and scientific basis for granting the loan. This will make the assessment more practical and more convincing. Investigation ivas made on the public participation of this project in preparing this assessment as required bv the World Bank. Public participation was invited during the process of this assessment according to the demands of the World Bank. The following is an account of the ways, scope, and result of the public participation. 8.2 Methods of investigation Many methods verc used for the public participation: sessions of ficld questions and answers verc held; qucstionnaircs wcre distributed, and experts' opinions and advice solicited. At thc same timc radio reporters' intervicws, TV programs and newspapers w"erc also mobilized to gathcr conccmcd opinions. suggestions, and demands for the proposed project. Materials thus collected were sorted out and classified for analysis. 8.3 Scope of investigation The proposcd projcct involves the whole urban arcas of the city. so the scope of the investigation carried out included the area along the construction line. Institutions investigated included the Municipal People's Congress, thic Municipal Pcople's Political Consultative Conferencc, thc Municipal Govcrnment, district govcrnmcnts and institutions, district pcoplc's congress, as well as dozens of enterprises, schools and neighborhood committees along the construction line. 8.4 Subject of investigation Reprcscntatives of the people's congress, members of the people's political consultativc conference, government officials, othcr functionarics of various institutions, doctors and nurscs, 164 professors and teachers, workers. students, and ordinarv inhabitants; experts and scholars in the fields of planning, environmental protection. construction, foreign trade and economy. and engineerng. 8.5 Method of investigation 8.5. 1 Random sampling was held at different levels among the masses of the people who will be directiv affected by the project Sampling taking was taken for the investigation in the 40 or so institutions and 15 neighborhood committees along the construction line based on their professions and cultural levels. Then questionnaires were given and wvere filled out on the spot. 8.5.2 Journalists from radio stations asked for interviews to solicit opinions and suggestions for the proposed project. 8.5.3 More than 30 experts and scholars in the fields of planning, environmenial protection, water conservancy. foreign trade and economy, engineering. ecology, and construction were invited to attend advice seeking conferences and testimony sessions for the project. Ten experts filled out questionnaires. 8.5.4 Mass medium like newspapers and TV broadcast vere adopted to publicize the Chaovang Stream comprehensive treating project and to solicit opinions and suggestions on the social, environmental, and economic impact of the project. 8.6 Analysis on the results of investigation 8.6. 1 Analysis of t/c quLestionnazres 174 questionnaires were distributed and 100% of them were recovered. Of the people investiQatcd. white collar staff took up 52%, workers 14%. general inhabitants 26%. and students 8%: male accounted for 63% of the pcople investigated anud female 37%; Those %%ith schooling up to the college level accounted for 39%. up to highi profcssional school level 14%o. and up to junior high school and primary school 47%. Investigated people were from 40 institutions and enterprises, 13 neighborhood committees, and I village committee. About 71% of the people investigated live in the area of the projects; 10% wvork in places in the area, and 10% arc to be removed to settle eisewhere. (I) About the awareness of the Chaovang Stream comprehensive treating project: 98% of the people investigated said that the had leamned about the project through TN' broadcast, nerspapers or other people, and 2% had not heard about it before. The investigation increased the project's transparency and aroused public concern over the project. (2) About opinions of the project: Mlasses of the community all expressed the opinion that the project would improve the appearance and envirotinment of Nanning City and bring benefit to the people. So 100% of then were in support of the project and hoped it would start soon. (3 ) About the environmental impact of the project: 165 100% of the people investigated said that thev held the project would have long and favorable impact on the environmental qualitv of the citv. The reduction of polluted wvater, solid ivaste matters, and atmospheric pollution wvill improve people's health and benefit generations to come. The project would have remarkable environmental and social benefit. (4) About the project's influences on the citv's economic development: 100% of the people investigated thought the project would be in favor to the economic development of the city. The project wvould reduce losses caused by water logging, improve the living condition of the inhabitants and environment, thus improving the investment environrnent the city, which would bring certain economic benefit. (5) About the impact of the construction of the project on people's life: 30% of the people investigated said that they wouldn't mind; 56% said there would be some impact but they could stand it: 14% said it would be unbearable, wvho wvere mainly concerned about the noise of the construction and unfavorable impact of the construction to people's life and traffic. (6) About the removal required by the construction of the project: The subjects of the investigation said that the removal vould cause much inconvenience but thev would be willing to accept the arrangement made bv the government and do their best to overcome difficultics. But they hoped thev wvould be compensated according to the policy and their living conditions could be improved wvhen they would be resettled. 100% of the people to be removed agreed to move. (7) Suggestions and demands of the community conceming the project a. Masses of the community showed great cnthusiasm in the public participation of the asscssnicnt for lhc project. Thlcy held that the Chaoyang Stream comprehensive treating project was a major event benefiting generations to comc by improving the city's cnvironncnt and landscapc. The city government should includc the project into thcir agenda and do a good job of it. It w%as suggested to mobilize social powers to donatc moncy and materials for the specdy construction of the projcct to improvc the citv's environment so their citv %Vill bc a bcautify the city. b. It was suggested that strict laws bc worked out and implemented. and administration bc strengthened. Illegal buildings should be demolished and their builders bc fined and punished. Preparation should bc donc for the projcct in an activc way. It was hoped that the construction wvould be carried out in stages according to the concrcc conditions of different segments. c. Effective measures should be taken during the construction so as to reducc thc unfavorable impact on peopic's lifc and traffic. Peopic to bc removed should bc well arranged. d. It -was prcferable to usc the open tunncl method so that there would bc a clear river. along which peoplc could rcst and hold recrcational activitics. 8. 6.2 Analysis of the interviews held by journalists Nanning Clty Radio Station sent out journalists before the national Day to interview 33 peoplc bclonging to diffcrent institutions and organizations, including the mayor, dcputy mare, 166 deputy director of the municipal people's political consultative conference. directors of the city's environmental protection bureau, education bureau, and construction commission, college presidents, professors and teachers, Party officials and students and inhabitants. Their suggestions and demands can be summed up as follows: (I) The Chaoyang Stream is seriously polluted and causes water logging in the wet season. directly influencing people's life along the river. It also affects the scientific research and teaching, even enrollment rate of schools situated near the river. Many proposals have been made by municipal and district people's congrcss for earliest possible trcating of the river. (2) The waste water flowing from the Chaoyang Stream into the Yongjiang River greatly affects the wvater quality of Lintie Water Mill. 100% of the concentrations of ammonia nitrogen and dissolved oxygen have been exceeding the standard. The water quality is, the worst among that of the four wvater plants in Nanning City. (3) All the people interviewed wvere eager to have the river treated and they hoped the government would be considerate of people's conditions and take radical measures to treat pollution and water logging. (4) Inhabitants to be removed and resettled are willing to obey the arrangement for the sake of the whole citv. Public donation can be solicited to cover part of the expenses. (5) It is necessary to raise people's sense of thc environment. Public medium should propagate for civilized habit of hygicne. and the government should take lead in this respect. Responsibility system should be set up and those who violet it be punished. Successive governmncnts should be determined to trcat the Chaovang Stream thoroughly through joint persistent efforts. 8.6.3 Analysis oni vieiws of the cxper!s (I) About the attitude to the project: All the cxperts and scholars cxpressed teilr support for thc construction of the proposcd project. (2) About the urgcncy of thc project: All the cxpcrts and scholars invcstigated thought tilc projcct was very urgent and imminent. 100% of them had a scnsc of urgency. (3) About the project's impact on the cnviromicnt: All the cxpcrts and scholar thoughit the project would improve the environmental quality of the city, especially the 'vater qualitv of the Chaovang Stream and the Yongjiang River and the wvater mills. Improvement of the city's appearance will bring rcmarkablc social and economic bcncfit and long temi favorablc impact to thc protcction of the environment of Nanning Citv. (4) About thc impact of the project on thc city's economic development: All thc expcrts and scholars thought the treating of the Chaoyang Stream wvould improve the citv's investment environment to be w\orthy of a provincial capital and an open city. Besides its cconomic bcnefit. reduction of water logging wvould also bring indirect cconomic bcnefit, as 167 the construction would surely promote the municipal engineenrng of the city and have far reaching influence to the city's modernization. (5) Suggestions put fonward by the experts a- 90% of the technical personnel and experts were against the plan of totally covered tunnel. A wide river vith clean water flowing through the central part of the city wvould greatly beautify the landscape of the city. The river with the green belts along it would help regulate the micro climate and improve the environment of the city. b. At present laws should be worked out to strengthen the administration over the Chaoyang Stream, clean away garbage along its banks, demolish illegal buildings and dredge the water wav. Those who violet them should be severely punished. Flood drainage capacity of the pumping station at the outlet of the Dakeng Stream should be raised to reduce wvater logging. c. The experts hoped the construction of the project would start as soon as possible and be earned out in a speedy way in stages in accordance with the concrete situation and strive to bring some benefit every year. d. Enough attention should be paid to the environmental impact caused by the sludge and noise during the construction and proper measures should be taken to reduce them. As a project with loan from the World Bank, the people to be rcmoved should be well looked after in the resettlement. 8.6.4 The role played by mass mediuim like radio stations and newspapers To publicize the project for higher public participation and public sense of the environment. Mayor Song Fuming instnicted that radio stations. TV stations. and newspapers should arrange to have contcnts about the environmental protection evcry dav. As a rcsult. Guangxi Radio Station, Nanning Radio Station. "Guangxi Daily" and "Guangxi Evening News" gavc a number of introductions to the aim. plans, effcct. administration of the Chao-vang Stream comprchensivc treating project. Guangxi TV Station broadcast twvo TV documcntaries on Septembcr 14 and 18, 1994 entitled Thc Trcating of the Chaoyang Strcam Is Inevitabic. Nanning TV Station also broadcast t-vo TV documentaries entitled Oh! Chaoyang Stream! in October that vear. "Guangxi Daily" published an article on October 14, 1994 entitled "Environmental Protection should Be Looked Upon as a Job Conceming Relieving People's Suffcrings", which reported the opinions of the Inspccting Group bv the National People's Congress on Enforcement of Environmental Laws. The newspaper again carmnd a necvs item on the substantial contact between the inspecting team of the World Bank and Nanning municipal authorities. The Radio and TV Information" also carried an article detailing the intervie of Deputy Mayor Chen Tingzheng. who is in charge of the project and Mr. Meng, Deputv Director of the Beihai Branch of Bcijing Municipal Engineering Designing Institution on the Chaoyang Stream comprehensive treating project, entitled The Chaoyang Stream Must Be Cleaned Up to Show its Original Charm. 168 "China Environmental News" also carried an reportage entitled When Will the Chaoyang Stream Become Clean?" on November 22. 1994. All these reports gave sharp contrast betwveen the original clean Chaoyang Stream wvith fish swimming in it and the present seriously polluted waste water ditch blocked by garbage. giving out foul smells, whcre flies and mosquitoes multiply. The situation has aroused strong resentment among the people, who demand imminent treatment of the river. These reports publicized the necessity and urgency of the project and strengthened public participation. positive to solicit people's understanding and support and favorable to the smooth carrying out of the project's construction. The fact that 100% of the people investigated support the project shows the citizens of Nanning Cit) have a strong sense of the environment, taking it as their duty to protect the environment and improve the city's appearance. The 'Municipal government and the Chaoyang Stream Administration have received a lot of letters from the masses , which express their support for the government's decision and demanding for the speedy treatment of the Chaoyang Stream. Some even sent their owvn designs and suggestions for the project. A reportage carricd in the June 3rd issue of "Nanning Evening News" tells how the teachers and pupils of No. 2 Kindergarten donated 1,142 yuan for the project, the first donation received for the project. This proved people's understanding and support for the project. 169 9. Conclusion 9.1.Significance of the project The main task of the Chaoyang Stream comprehensive treating project is to renovate the nver course of the Chaoyang Stream. to build up the net work of rain water and waste water pipelines in the urban part of the city. and to build waste treating plants for the city. The project will be able to solve serious problems like flood and water logging by gathering 40% of the waste water discharged by the city and solve. thus greatlv improving the environment of the central part of the city, alleviating the pressure of waste water from Nanning to the Yongiang River. It wrill improve the water quality of the-Yongjiang River and protect the -water source of the city. So, as a comprehensive environmental protection project tallving with the overall plan of the citv, the project will bring great environmental, social, and economic benefit 9.2 Impact of the project on the environment The environmental impact of the comprehensive treating of the Chaovang Rive will be mostly extensive, positive and of long temi. Its negative impact, mainly during its contraction, is of short temi and local. 9.3. Existing environmental quality 9. 3. Environmenta/ qiali iv of szurface water Monitoring data show Thhe watcr bodics of the Chaovang Stream, the Erkcng Strcani, the Zhupaichong Stream, and the Shuitangjiang Stream arc all scriously polluted, major pollutants bcing COD and BODs, followved by NFH3-N. as a whole no longer mecting the standard for Gradc V surfacc water. Tnhc water quality of the Yongjiang River is fairly good bcfore it cnters Nanning City, Within the standard for Gradc Ill of surface wvater exccpt fcv items like (SS. oil and NH3-N). Aftcr passing through thc city, affccted by the scwagc and industrial wazstc wvater discharged into it, its water quality turns remark-ably vworsc. no longer mecting the standard for Gradc Ill surface watcr. And the tendency of detcrioration is going on and the major pollutants arc organic mattcrs. 9.3.2 Qzuality o atmosp-heric environment The average daily value of SO- in Nanning City is 0.064mg/ni3, cxceeding the standard for 17() Grade 11 of national standard of the atmosphere, that of TSP 0.201mg/m;, xvithin the standard for Grade 11 atmosphere but exceeding the standard for cities in south China (0.20mg/m') as set be the state, that of NOX ranges from 0.008 to 0.012mg/nim. So, major pollutants affecting the city atmosphere are TSP and NOX. 9 3.3 Acozustic environmental quality As for the acoustic environmental quality of Nanning. the equivalent sound level in functional regions of Nanning City in 1994 averaged 61.7OdB(A) during day time and at night-, exceeding the standard for Type f1 areas set in "Urban Area Environmental Noise Standard". The actual monitored average values was 53.4dB(A). exceeding the standard by 5.4dB(A). The noise pollution in the city has a tendency of increasing along NNith the opening up of thf:itv, the renovation of the old part of the city, and the flourishing of the real estate market. 9..3. 4 Solid itastes Industrial solid wastes from industry and daily life in Nanning in 1994 amounted to 806 5OOt, of wvhich industrial wvastes amounted to 558 5OOt. accounting for 62%, and daily life garbage 248 OOOt. accounting for 37. 1%. The rate of comprchensivc utilization of industrial solid wxaste matters has reachied 86%. However, thoughi 100% of the city's domestic garbage was transported away, only 28 OOOt w'as treated to bc hamiless, accounting for oniv 11.3% of the total. So daily life garbage is causing morc and more serious pollution. 9. 3.5 Bototom clay of thle Chaoyang Stream Asscssment of the bottonm clav with Flakanison indcx method shoxved that the hecavy mCtals contained in it poscd as a potcntial hazard to the ccological system. The RI risk index of the bottom clav of thc Chaovang Stream nwas 1400, of cxtremc harmfLlness 9.4 Prediction of the projects' envrionmnental impact and prevention measures 9(. 4 1/ rediction of the impact durirng the constrnction of the project 1. Prediction of the environmental impact of the renovation of thc Chaovang Strcam during its construction (1). Environmental impact of thc bottom clav of the Chaovang Stream In the projcct of thc rcnovation of the Chaoyang Stream. a total amount of 0.2 million ml of bottom clav shall bc dredgcd. Tcsting found it containcd 13.70% organic matters'. The concentrations of mincral oil, Hg, Cr. Cu, and Zn respectively rcached I 196mg/kg, 2.33mg/kg, 1 71 212.4mg/kg. 132 346mg/kg, and I 805mg/kg, denoting serious pollution. Assessment wlith Honkanson potential risk index method found its potential ecological risk index (RI) reached 400, being extremely harmful. Secondary pollution may occur dunrng the digging, transpiration, and disposal of the bottom clay. (2). Noise produced by machines used to dredge the bottom clay of the Chaovang Stream Excavators, bulldozers, and loading machines used in the dredging xvill affect sensitive places of living quarters and schools within lOOm of both banks of the Chaovang Stream. The noise produced exceeds the standard by 2-5dB(A), lasting 20-30 davs. (3). Environmental impact of the bottom clay piled temporarilv Under normal conditions -when the w1ind speed is 2.5m/s. the concentration of the TSP from the piled bottom clay can reach 490mg/m3 at a distance of I Om in its leeward.. exceeding the stal*iard for Grade 11 atmospheric standard set bv the state by 1.6 times. The bottom clay piled may leak out 20 OOOm3 of percolate, whose BODs concentration may reach 20 OOOmg/L, giving out fouls smells of the fourth level, This is serious secondary pollution and wvill affect the landscape of the city. (4). Impact of house removal and inhabitant resettlement Buildings to be removed involve an area w%ithin 30-68m along both banks from the middle of the river. 769 households wvill be resettled, with a population of 4506. The resettlement of the inhabitants will be arranged by thc overall plan of the citv. They are to resettle in Luwei quarters of Xinvang Road and Zhongxiao Road quarters. The life quality and living conditions of the inhabitants resettlcd will have much improvement. 100% of the peoplc involved in the public participation are in support of the project. Tlhe rcmoval of the houscs will produce 65 million m3 of construction garbage. which w ill be transportcd to Santang garbage filling ground as part of the city's garbage. With othcr administrative and controlling measures, this will not causc much negative impact on thc arca around the construction site of the project. 2. Prediction of the cnvironnicntal impact of the project of the city's scvage system (1). Environmental impact of raised dust during construction Analogical investigation finds out that raised dust during construction may affcct thc area ,within 50-IOOrn in the lccvard of the construction sitc. where the conccntration of TSP can reach 0.37-8.6mg/ni. 1.5-5 timcs that in the contrasting point in the wvindward direction.. Transportation of cartlh to be flack idled and cast awvay may affect a distance of I Om in its Ieeward. Thc conccntration of TSP at both sides withlin 5m from the road can reach 8- I Omg/m3, cxceeding the standard by 30 times. (2). Environmental impact of construction noise Construction machines arc the main noisc sources.. Without considcnng the attenuation causcd byv houscs and trecs, thc rangc affected may reach l OOm during daytime and 300m at iiglht. (3).1mpact of the construction on the citv's traffic 30-50% of the road surface will be occupied for laying pipelines. which scriouslv affcct traffic. causing traffic jams and affcct pcoplc's nornal work and lifc. 172 (4). Environrnental impact of pipeline desilting Statistics shows that 22 pipelines with a total length of 28.4km are silted with 52 600m' of sludge, whose foul smells can affect an range of 25m. wvhere the concentration of foul smells may reach 15-30, exceeding the standard by 0.5-2.0 times. 9.4.2 Prediction of the impact during the operation of the project 1. Prediction on tihe environmental impact after the Chaoyang Stream trcatmcnt projcct is put into operation (I). Polluted belts along the banks of the segment of the Yongjiang River at the outlets of the Chaovang Stream, the Erkeng Stream and the Tingzichong Stream will be relieved. favorable to the protection of the water source of Lintie Water Mill and improvement of the environmental quality of the Yongjiang River. The outlet of waste water dischargc is removed dowvn to the outlet of the Shuitangjiang Stream, ridding the potential threat to polluted the water cnvironmental quality of the central part of Nanning City by the Chaoyang Stream and the Erkeng Stream. This will play an unreplaceable role in building Nanning into an intcrnational garden city with its unique characteristics. The completion of the project will realize the long cherished wvish of "drawing water from the upper reach and discharge wvaste water to the lo%%er reach", so that the functions of the citv Nvi1l be in better coordination to produce much environmental economic bencfit. (2). Tlic compiction of the project wvill radically improve the water environment of the Clhaovang Strcam. turning it from a sewage ditch into a clean ricr for landscapc. This is the most direct manifcstation of thc cnvironmcntal benefit of the project. After the projcct is put into operation. wvater will bc draw%n from the Yongaiag River into the Chaoyang Stream. so thc lather's water quality xvill bc guaranteed for most years. Changing of water replcnisilnlig period can keep the wvatcr quality of the Chaoyang Stream at a fairlv high level. As the amount of w\atcr chanigcd is comparativcly small, and thic water quality of thc Cliaoyang Strcam is much bcttcr than the original waste wvater, not muchi cffcct w\ill be caused to the water quality of the Yongjianlg River. It is suggested that artificial springs and wvaterfalls be built in thc construction of thic water supplemcnt system of the Chaoyang Stream in coordination with thc rcnovation of the citv. so tihat thc city %vill be morc bcautiful and more oxygen can bc restorcd in thc wvatcr body. As a rcsult. its quality can maintain a longer period to lesscn the Nvater chaniging frequency. As the prcscnt dcsign contains no water rcplcnishmcnt to the Tingzichong Stream . the projcct vill not havc much cffect on its wvatcr qualitv. The watcr surface of the stream shriniks too muIch in the low \vatcr season and there won't bc any improvement on the landscape It is suggcsted supplemcntal dcsign bc made on the wvater replenishment to the Tingzichong Strcam and carry it out in propcr time. (3). According to the plan of the project. waste Nvater \vill be led to thc outlet of the Shuitangjiang Strcam throughi rivcr crossing pipelinies. This is much better environmentallk than the alternate plans that plan to Icad waste water to the wvaste wvater treatinig plant in 17' Langdong. To lead the tail wvater to be discharged into the Zhupaichong Stream. can prevent the water quality of the Zhupaichong Stream from getting wvorse than the present condition and make it easv for it to reach the standard for Grade V water in the future. To build the waste water treating plant in Jiangnan instead of in Langdong will save much fund of waste water transportation. (4). After the project is put into operation, the polluted belts along the river banks in the central part of the city will be reduced or totallv illuminated. but the polluted belts in the Shuitangjiang Stream will grow longer, increasing local pollution intensity. But as waste water from the citv will be discharged into the Shuitangjiang Stream, shortening the distance to the countv seat of Pumiao, the amount of %%aste water allowed to be discharged xxill be reduced- This is the inevitable price for cutting the pollution in the central, part of the city. The completion of the project will reduce 10% of total BODs load, this can improve wvater qualitv at the dow.n stream area of Pumiao. The completion of Jiangnan w%aste water treating Plant at the outlet of the Shuitangjiang Stream will reduce 70% of total BODs load (at the load level of vcars of normal water in the plan). It controls pollution effectivelv to down stream. This can be 'solved by raising the treating level and amount of the Jiangnan wvaste water treating plant. so as to achieve coordinated development of the cconomy and the environmcnt. (5). At the scale of 260 000m3/d as the capacity of the first stagc of the Jiangnan "'astc water treating plant. the rate of BOD, cut can reach 35%, equivalcnt to reducing 91 000m3/d of waste water. The amount of waste watcr from the citx in 1996 was 597 700ml/d. that in 2000 is estimated to bc 682 000m3/d. In normal ycars. the amount of BOD5 entering thc Yongjiang River thcn wvill be about the samecas present (1996). If the BOD3cutting ratc can not reach 35%. with thc discharging point shifting castwmrd, the DO levcl of the Pumiao segmcnt will continuc to detcrioratc. To v ie%v the issuc from the total amount of control. level one trcatmcnt of the 200 00Om3/d wvill cut 15% of the total pollution from the city. It can thus be seen, thc projcct will have rcmarkablc effect in controlling the detcrioration of the water qualitx in the lowcr reaches of thc Yongjiang Rivcr. It is one of the most important steps to maklc the segment of the Yongjiang Rivcr from the Shuitangjiang Strcam to the Pumiao Rivcr reach the standard for Grade Ill water. 2. Prediction of thc environmcntal impact of the drainagc s!stem of the citv when in operation The complction of the rain water pipclinc netxvork will play a decisive role in solving the scrious wvatcr logging of the city, tallying with the demand sct in "Drainage Plan of Nanning Citv". It also will also have positivc.cffcct on the hygicnc and landscape of the city. The operation of the rain wvatcr pipclinc nctwork wvill not havc much impact on thc watcr quality of thic Yongjiang River and its tributaries. (I). Thc thrcc trunk rain water pipclincs discharginig into the Nanhu Lake arc the main non-point input entcring the lake, playing a remarkable rolc in restoring the water quality of the lakc. Aftcr the complction of the waste watcr interccption projcct around the Nanliu Lake. non- point sources will control thc wvatcr qualitv of the lake. This max causc environmental problems like eutrophication of the lake. During low wvatcr lexel period, there may be lack of water. So the Nanhu Lake is facing dual problems of wvater replenishment and non-point sources pollution. (2). The completion of the waste water trunk} pipelines in Tinghong Road and Baisha Avenue will brng waste water in Jiangnran Distnrct into effective control, making full use of the functions of the trunk waste water pipelines in Jiangbei and the Jiangnan %vaste water treating plant. This xwill surely diminish the polluted belts along the outlet of the Tingzichong Stream to the Yongjiang River. Plus the function of the Jiangnan waste water treating plant, it w-ill alleviate the deterioration of the water quality in the loxwer reaches at Pumiao. a. The two wvaste water trunk pipelines Will cut the pollution concentrations, restoring 17O vater environmental capacity of that segment of the river. b. The water environmnent upper the outlet of waste wvatcr treating plant at Shuitangjianc can be remarkably improved, reaching the standard for Grade V water in part time of the year. (3). The renovation of sewage pipelines is actually the construction of branch rain water pipelines. Before the completion of wastc water pipeline netwvork, it will not cause the redistribution of point and non-point sources pollution. nor detenrorate the present discharge of wvaste wvater. This can solve the problem of serious wvater logging because the pipelines in these areas are too narrow. 9.4.3 Measures to eliminate negatiove impact I. Preventive mcasurcs to be taken during the construction of thc project (1). Strcngthcn the administration, planning and mianagcmcnit of thc constrtction. and carrv it out by stages and sections so as to raise efficiencv and shorten construction titime. Duo up carth should bc bank fillcd and road rcstored in timc, so as to redtucc raised dust. noise. foul smclls and impact on the traffic of the city. (2). Optimize the time of working, avoid the use of machines at niglht that producc strong noise, so as to reducc the impact on peoplc's life. (3). Establish temporary traffic routes in down-town arcas and busy traffic routes, and assign peoplc to direct vehicles so as to prevent traffic jams. (4). Carry out the drcdging of the Chaoyang Strcamii in thc dry scason. and timely transport zvay bottom clay dug up, so as to prevent it from %%ashcd into thc river by rain. It is suggested to usc cncircled bank for the piling and burial of bottom clay so as to diminislh its cnvironmental impact. 2. Countermcasurcs to bc takcn during the operation of the projcct (I ). Telc feasibility report did not study thc problenm that the threc trunk pipelines for rain watcr to be discharged into the Nanhu Lakc will cause difficulties for the treatmcnit of the initial rainl which bring heavy pollution into thic lakc and \\aste mooney as the tlhrec pipelines arc not connected. It is suggested. aflcr thic determination of altemate plan, to adjust the dcsign of the dcpth of the pipelincs in Qixin-Jiaovu Road and Taosuan Road, so that the problem of initial 175 rain can be solved. (2). It is suggested to redesign the flow of the waste wNater pipelines in Tinghong Road and Baisha Avenue as the original design is too small to lead the waste wvater from major industrial polluters into Jiangnan waste water treating plant. (3). There should be vibration damper in the waste water pumping station at the outlet of thc Dakeng Stream, so as to reduce the impact of noise on nearby inhabitants. (4). All together a total amount of 336 000m3/d (1994 data) of waste water needs to be treated by the Jiangnan waste water treating plant after the completion of the renovation of the Chaoyang Stream and the sewage system. But the capacity of the plant is only 260 0003/d. So it is suggested that the design of the scale of the Jiangnan waste w ater treating plant be enlarged. 3. Capacity of the Jiangnan wvaste water treating plant Form the viewpoint of the watcr environment of the Yongjiang River, it is necessary and urgent to make the plant be capable of level I treatment. Main reasons: (I) Analysis of practicality shows that it is very difficult for the vater quality of the Yongjiang River (especiallv the segment in the lower reach at Pumiao) to meet the standard for Grade HII surface water under the designed condition (Qp.W.,=170m'/s). The water quality index arc DO and NH3-N. According to the field monitoring carried out in 1991-1994, the flow in low water lcvel period was 1.5 times over the designed flow, when the concentration of DO exceeded thc standard for Grade Ill water. The actual oxygen was about 1.5 times that of usable oxygen. This reveals that Nanning City poses as a serious threat to the water in its lower reaches, especially to the composition of aquatic organisms. (2) According to the result of the "Studv on thc Plan of the Environmental Capacity and Water Qualitv of the Yongiang River" (Nov.. 1993), the discharge of BOD; allowed from the oLitlet of the Machao River to thc outlct of tie Shuitangjiang Stream is 378.7g/s, cquivalcnt to 222 600m'/d of waste water discharged. So the environmcntal capacity of thc Yongjiang Rivcr is fully occupied sincc the beginning of the 90's. The actual amount discharged was twicc morc than the allowed amount. Aftcr the completion of the projcct, waste water discharging will be shiftcd eastwards to the Shuitangjiang Strcam, the allowed amount of discharge wvill still cut bv about 200 000m /d. Thereforc the treating should cut BOD, by 60% in thc year when the projcct is complcted, and 83% in normal ycar designcd (2015) to mect the demand of DO of the watcr quality. (3) The abovc analysis states that the design of the Jiangnan waste water trcating plant should be able of level two trcating to mcet the dcmand of the environment. It should be able to carrv out level I treating in the near fiturc to maintain the water quality and prcvcnt it for furtlhcr dctcriorating. If thc wastc water is trcatcd in the level of pretrcatmcnt. the pollution load Cult will not bc able to catch up with the incrcasc of pollution load. and the pollution will bc worse than the prescnt as soon as the projcct is completcd. (4) If the Baise Reservoir is to bc built within ten years. the runoff flow during the low water pcriod can rcach Q,,. 90=300nl/s. a littlc largcr than the runoff monitored in 1991-94, 176 the discharge allowved can increase to 350 OOOm /d or so, then the wvaste wvater from the citv still needs to be treated. If the waste water increases to 650 000m3/d, the treating rate required will be 46%. So if the Jiangnan waste water treating plant is designed with a capacity of 520 000m3/d and level I treating, there wvon't be any waste of fund. So the project should build a level I Nvaste water treating plant at the outlet of the Shuitangjiang Stream in the near future. which wvill be enlarged to level 2 treating later. Such design tallies wvith the economical development of Nanning Citv and at the same time taking into consideration the demand for environmental protection. It is more practical than to build the plant of level I treating in one step. 4. Addition of investment of the Jiangnan waste water treating plant The feasibility report only altos 17.44 million yuan as the investnent for the Jiangnan waste water treating plant. This is far from enough to make it reach level I treating. It is thus suggested to add its investment according to the level I treating design in the feasibility report report of the project. 5. Charge on waste wvater discharge The improvement of the water environment of Nanning City and the water qualitv of the Yongiiang River depend on the rational ratio of cconomic development and investment for environmcntal treatment. The Investment of cnvironrmental treatment needs rolling development. It is thus suggested to charge waste water dischargc fee during the operation of the project, so that it will be able to pay the loan and operational expense, and collect fund for the further dcvclopment of the Jiangnan waste water treating plant and waste watcr collecting system. This will bring a benign cyclc of water pollution control and rolling dcvclopment. 9.5 Comparisoni of plans Aflcr analyzing and comparing the recommcndcd plan and alternate plans fomi the angics of cconomic bencfit, environimiental bcncfit. and social benefit, it is concluded thiat the rccommcnded plan for the comprehensive treatmcnt of the Chaovang Strcam is the most rational. 9.6. Anialysis of the benefit of the project lihc Chaoyang Stream comprehensive treating project will bring great environmental beniefit and social bcncfit bv solving the problcms of flood and watcr logging xhich havc been vorrying the city for years and improvc the sewagc systeimi of the city, thus greatly improving the citv's landscapc and pcopic's living conditions. Thc projcct can collect and treat ovcr 60% of the cav's waste water, thus reducing the pressure on the polltitioni and environmental capacity of the Yongjiang River and protccting its water quality The procect is financially practicable as thc main fund of the construction is investment from thc governmcit during its construction 177 9.7 Public participation Opinions -were solicited from people from 1 neighborhood committees wvith 174 households and experts of various fields. The results showed that 100% of the investigated people supported the construction of the project. 86% of the inhabitants said they could understand the short impact of the construction, only 14% though it unbearable. If the removal of the houscs and resettlement of the inhabitants are carried properly with proper policies, their attitude will surelY change to support the project for the overall interest. To sum up, the Chaovang Stream comprehensive treating project is an environmental protection project that will bring remarkable environmental benefit, social benefit and economic benefit. It tallies with the overall plan of Nanning City and is totally practical. 178 Bibliography I. Feasibility Report of the Chaovang Stream Comprehensive Treating Project in Nanning, Oct. 1995, Beijing Municipal Engineering Designing and Research Institute 2. Outline of the Environmental Assessment on the Chaovang Stream Comprehensive Treating Project in Nanning. Apr., 1995. Chinese Academy of Environmental Sciences 3. Report on the Work of the Government, 1993, 1994 4. Plan for Environmental Protection of Nanning City during the Ninety Five-year Plan and the Long Term Plan for the Year of 2015, Nov., 1994, Nanning Municipal Environmental Protection Bureau 5 Studies on the Plan of the Environmental Capacity of Water Quality of the Yongiang River. Nov., 1993. Nanning Environmental Monitoring Station 6. Handbook for River Cross Section Calculation. Mar., 1995, Xijiang Bureau of Water Conservancy Committee of the Ministry of Water Conservancv 7. Studies on Heavv Metals in China's Water Environment, Chen Jingshcng. etc., 1992. Chinese Environmental Publishing House 8. Initial Design Report on the Treating of the Chaovang Stream in Naning, Feb. 1994. 0Guangxi Hydropo\er Designing Institutc 9. Statistics Yearbook of Nanning, 1994. Jul.. 1994. Nanning Municipal Designing Bureau 10. Report on tihe Plan of Flood Prevention in Nanning City. Nov.. 1994. Nanning Municipal City Planning Institute 11. Report on Environmental Quality of Guangxi Zhuang Autonomous Region, 1993. Environmental Protectionl Agency of Guangxi Autonomous Regionc 12. Report on the Ensvironment of Nanning City. 1991, Nanning Environmental Protection Bureau. Ctc. 13. Feasibility Report oln the Dredging of the Bottonm Clay of Chahai of Lake Dianci In Kunming. a Subprojccts with Loan from thc World Banik. Mar., 1995. Chiinesc Acadcmv of Environmental Sciences Appendix Document Jitouzi (1994)1441 issued by the State Planning Commission Reply to the Report on the Proposal of Environmental Protection Projects in Guangxi Using Loans from the World Bank October 10, 1994 planning Commission of Guangxi Zhuang Autonomous Region, Your report Guijibao (1994) 79 and 200 has been received and studied, and hercafter is the reply to them: 1. It is principally agreed to carry out the Guangxi environmental protection projccts using loans from the World Bank, that is, the comprehensive treatment of the Lijiang Stream in Guilin .and the Chaovang Stream in Nanning. The concrete plans for thcir implementation will be determined aftcr rational comparison and testament of the studics on their feasibility. 2. The cnvironmental protection projccts in Guangxi wvill use loans of 100 million US dollars from the World Bank wvith one billion of RMB intcmal invcstmcnt to go with it. T1he repayment of thc loani from thc World Bank and the fund for the intcmal inivestment shall bc thc responsibilit' of the autonomous rcgion itsclf. T1he amount of both items will bc included in the scalc of capital construction as allottcd to the autonomous region by thc ccntral govcrnmcnt. 3. Makc a good and specdy job of the feasibility rcport of thc proposed projccts and preparation of the conditions and fund for thcir construction. arrangcmcnt of the loan from thc World Bank. and plans for its rcpayNment. All thesc should bc scnt for approval of this commission. nhc scrial number of the loani is X9400003030 17. Document Guihuanban (1995)37, issued by the Environmental Protection Agency of Guangxi Zhuang Autonomous Region reply to the standard to be adopted for the cnvironmental assessment on the Chaoyang Stream comprehensivc trcating projcct July 10, 1995 Chinese Research Academv of Enxironmental Sciences. Your lettcr dated April 4. 1995 has been received. Upon study, wve here agree to the standard to be used for the environmental assessment for the Chaoyang Strcam comprehensive treating project as was proposed by the Nanning Municipal Environmental Protection Bureau(see appendix). Please proceed with the assessment as required according to the standard. Appendix: The following standards are to be used for the environmental assessment for the Chaoyang Strcam comprehensive treating projcct based on the enivironmcntal charactenstics of the constnction cites and stidies by Nanning Municipal auEthoritics and departments concerned: 1. For the water quality of thc Chaovang Stream: Standard for Grade V surface water as sct in Document GB3838-88 "Standard for Environmental Quality of Surface water" with rcfercncc to the standard for Grade C surfacc water as set in Document GB 1294 1-91 "Water Qualitv Standard for recrcation vatcr Bodics": 2. For the water quality of the Yongiang River: Standard for Grade IlI of surfacc vater as set in Documniet GB3838-88 "Standard for Environmental Quality of Surface Water"; 3. For xwatcr bodies of the Erkcng Stream and the Zhupaichionig Streamii Standard for Grade V surfacc water as scEt in Documcnt GB3X38-88 "Standard for Environimiental Quality of Surface watcr". Their water quality shiould bc appraised to be not worse than thc prescnt situation before (including) the ycar of 2000; 4 For the bottom clav of ttic Chaomang Stream and sludgc produced by Langdong wvaste water treating planlt. standard for acidic soil as set In Document GB4280-84" Controlling Standard for Pollutanits Contained in Agricultural Sludge" 5. For tail water from Langdong waste water treating plant: Standard for Grade 11 as sct in Documeilnit GB8978-88" Standard for Wastc Water to Be Discharged': 6. For noise standard set in Documcnt GB 1223-90 "Limited Value of Noisc of Constrtuctioni Cites" and the standard for type It of mixed quarters set in Docunent GB13096-93 "Urban Environimcntal Noise Standard"; t 7. For atmosphleric quality: Standard grade It sct in Document G13309-X2 "Standard for Atmosplheric Environmcltal Qualitv"; 8. For ground water: Standard sct in Document GB5749-85 " llygicne Standard for I)rinking wvatcr and %xater for Dailv Life". 3 f- 4 Document Guijibao (1992)234, report to the State Planning Commission by Guangxi Zhuang Autonomous Region Rcquest for Approval on the Chaovang Stream Comprehensive Treating Project in Nanning and Application for Including in Altemnate Items to Use Loans from the World Bank September 14, 1992 State Planning Commission, The Chaoyang Stream is a seasonal river and a natural waste wvater receiving river in the central part of Nanning City receiving about 83,000m3/d of industrial waste water discharged by over 50 entcrprises and domestic sewage discharged by 220,000 people (amounting respcctively to 35,000m3/d and 48.000m3/d. As the quantity of wvater from its upper stream is venv limited, and the waste water received surpasses its self-clcanilig capacity and drainage capacity, plus the silt and castaway waste matters brought by thic rain. the river bed has been narroxved and its bottom level raised. Large quantities of organic and inorganic mattcrs havc accumulated on the bottom of the rivcr. As a result, the rivcr is now scriousl% polluted: it looks black, giving out foul smiells. Thie river has becomc a place for mosqtito and fly multiplication. Monitoring by thc environimental protcction institute of the city finds: The averagc conccntrations of BOD, and COD of the river water have respectively reached I nimgIL and 227mg/L. The Nanning City authoritics have organized pcopic to trcat thic Chaoyang Stream scvcral timiecs but with littlc cffcct. Public appeal for the trcatment of the river has bcen growing as peopic's scencs of the cnvironmcnt has bccn raised in rcccnt vcars. nic Municipal Govcrnmcnt of Nanning has taken thc treatment of the Chaovang Strcam as onlC of Its ke\ municipal ciigiticering projects and has cntrusted the South China Designiing Institute to carr\ out initial work for thc projcct. Its fcasibility report is nowv rcadv (sec appendix) and tw\o alternatc plans havc bccn workcd out for comparisoni. According to the first plan. the \"asic water will be gathercd for treatmcnt bcfore it is discharged, the rivcr bed shall be dredged and cicar water soLirce wviIl bc opcned in tihc uppcr rcach so as to incrcase thc .nouLnt of thc water in thc Chaovang Streamn and improvc its water quality. According to the sccond plan. most part of the Chaovang Strcam will be turned into a cover up tunnel, and the waste water k%ill be gathered to be discharged into the lower reach of thc Yongjiang Rivcr after treatment. Designing institutions hold that the second plan requircs comparativcl) simpler engineering vork and less investment and less fee for its operation. Initial cxamination finds the recommended plan is feasibic.. The completion of the project vill radically change the internal environment of the Chao-vang Stream drainage area, bringing remarkable social and environmental benefit. It is estimated that the total investment needed for the project is 468.5 million yuan (including 21 million yuan for paying for the interest during the construction of the project). Its main engineering wsork includes: 150,000m3 of sludge to be dredged from the rnver. 380,000m3 of earthwork to be done for the treating of the river bed, 8,500m of covered tunnel to be built, two pumping stations to be built for flood drainage and wvaste water discharge. a waste water treating plant with the capacity of I 20,000tIa to be built. The whole construction will last four years. As this project is of a large scale and will bnrng great social and environmental benefit, it is planned to ask for a loan of 60 million US dollars (equivalent to 324 million yuan of RMB) from the World Bank and Nanning City %vill see to the 144,5 million yuan of intemal investment needed. The capital of the loan and the interest will be paid back bv polluting discharging fee and city Maintenance fee to be levied by Nanning City authorities. .This is to request the approval bv the State Planning Commission for the proposed project and list the loan as an alternate item using loans from the World Bank. Instructions from the State Planning Comnnission are sought. Appendix: Feasibilitv Report of the Chaoyang Stream Comprehensive Treating Project (as a substitution for the proposal of the project) Document Guizhengban (1995)59, issued by the Office of the People's Government of Guangxi Zhuang Autonomous Region Reply to the Report of the Chaovang Stream Comprehensive Treating Project March 1. 1995 Municipal people's government of Nanning City. Document Nanfubao (1995)13 "Request for Approval on the Chaoyang Stream Comprehensive Treating Project in Nanning" has been received and studied and here is the replv: 1. The third plan is approved, that is to build covcred tunnel in the upper reach and open tunnel in the lower reach of the river, and then waste water will be interccpted separatelv in the upper reach and in a concentrated manner in the lower reach to be pumped at the rivcr mouth for treatment in the waste water treating plant. 2. Please do a good job of thc preparatory work for the project according to thc approved plan for the loan from the World Bank. Do vour best to start thc construction as soon as possiblc. Certificate of Entrustment of Environmental Assessment of the Chaoyang Stream Comprehensive Treating Project in Nanning as an Environmental Protection Item Using Loans from the Viotu Bank March 22, 1995 Chinese Research Academv of Environmental Sciences, Thc Chaovang Stream comprehensive treating project in Nanning has been approved by thc State Planning Commissions (sec Document Jitouz 1994-1441) as an item using loans from the World Bank. The feasibilitv report of the project has been compiled by the Beijing Municipal Engineering Designing Institute. Now we entrust vour institute to work out the environmental assessment of the project. Concretc contents and scope of the assessmcnt will be stated in the contract to be signed later. the assessmcnt is required to have testament and assessment bv cxperts in the country and meet the requirement set by the World Bank. Its outline should be completcd before April the fifth and the assessment complcted within two months after the outlinc is approved.