CHƯƠNG 1 - All Documents | The World Bank
E1787
ENVIRONMENTAL IMPACT ASSESSMENT (EIA)
01/2008
TABLE OF CONTENT
TABLE OF CONTENT ii
LIST OF FIGURES vi
LIST OF TABLES vii
CHAPTER 1 INTRODUCTION 1
1.1 INTRODUCTION 1
1.2 LEGAL AND TECHNICAL DOCUMENTS 1
1.2.1 Legal base 1
1.2.1.1 Requirements of Vietnamese legislation in Environmental Impacts Assessment 1
1.2.1.2 Requirements of World Bank on Environmental Impact Assessment 2
1.2.1.3 Local documents 2
1.2.2 Technical documents in Environmental Impact Assessment (EIA) 2
1.3 ORGANISATION 3
1.3.1 Environmental screening 3
1.3.2 Report contents and form 4
1.3.3 Research team 4
CHAPTER 1 PROJECT SUMMARY AND DESCRIPTION 5
1.1 GENERAL INTRODUCTION 5
1.1.1 Project implementation situation 5
1.1.2 Project principles and objectives 5
1.1.2.1 Project objectives 5
1.1.2.2 Project principles 5
1.2 PROJECT DESCRIPTION 6
1.2.1 Project title 6
1.2.2 Investors 6
1.2.3 The design consultants 6
1.2.4 Total investment capital and capital framework 6
1.2.5 Project Implementation Progress 7
1.3 PROJECT LOCATION 7
1.3.1 Proposed locations 7
1.3.2 Site selection 7
1.4 PROJECT SCOPE 8
1.4.1 Determination of the necessary demand of project 8
1.4.2 Technical standards 9
1.4.3 Output capacity and treatment requirements 9
1.4.3.1 Capacity 9
1.4.3.2 Components and characteristics of the influent 11
1.4.3.3 Effluent standards 12
1.4.3.4 Description of the outline of WWTP 12
1.4.3.5 Preliminary and primary treatment 12
1.4.3.6 Secondary treatment 13
1.4.3.7 Effluent disinfection before discharge into receiving water 14
1.4.4 The land requirements and cost estimation for three alternatives 18
1.4.5 Accompanied facilities 18
1.4.5.1 Transmission pipeline to the treatment plant 18
1.4.5.2 Effluent pipeline and Outlet Structures 19
CHAPTER 2 NATURAL, ENVIRONMENT, AND SOCIAL-ECONOMIC CONDITIONS IN THE PROJECT AREA 20
2.1 NATURAL ENVIRONMENT 20
2.1.1 Geographical Location, Topography and Geology 20
2.1.1.1 Geographical location 20
2.1.1.2 Topography 20
2.1.1.3 Geology 20
2.1.2 Meteorology- Hydrograph 21
2.1.2.1 Meteorology 21
2.1.2.2 Hydrography 23
2.2 ENVIRONMENTAL STATUS AT THE PROJECT AREA 23
2.2.1 Air environment status 23
2.2.2 Water environment status 24
2.2.2.1 Surface water 24
2.2.2.2 Thi Nai lagoon 25
2.2.2.3 Groundwater 25
2.2.3 Biodiversity 25
2.2.3.1 Agricultural ecology at the project site 25
2.2.3.2 Thi Nai Lagoon 26
2.3 SOCIO-ECONOMIC CONDITION AT THE PROJECT AREA 27
2.3.1 Overview of Socio-Economic Status at Project Area 27
2.3.1.1 Residence Status and Income of Household 27
2.3.1.2 Accommodation status 28
2.3.2 Status of water supply and sewerage 28
2.3.2.1 Status of water supply 28
2.3.2.2 Existing drainage and wastewater treatment status 29
2.3.3 Collection of solid waste and septage 31
2.3.4 Status of flooding 31
2.3.5 Power Supply and Lighting Status 32
2.3.6 Master plan of Water Supply for Quy Nhon City (until 2020) 32
CHAPTER 3 ENVIRONMENT IMPACT ASSESSMENT OF THE PROJECT 33
3.1 ENVIRONMENTAL IMPACT ASSESSMENT IN CASE OF WITHOUT PROJECT 33
3.1.1 Phase 1: Q = 7000 m3/day 33
3.1.2 Phase 2: Q = 28,000 m3/day 34
3.2 OVERVIEW OF THE IMPACTS BY THE CEPT WASTEWATER TREATMENT PLANT 34
3.3 IMPACTS IN THE PRE-CONSTRUCTION PHASE 37
3.4 IMPACTS IN THE CONSTRUCTION PHASE 39
3.4.1 Impacts on the air environment 39
3.4.1.1 Air pollution 39
3.4.1.2 Noise pollution 40
3.4.2 Impacts on the water environment 40
3.4.3 Impacts of solid waste 41
3.4.4 Other impacts 41
3.5 IMPACTS IN THE OPERATION PHASE 42
3.5.1 Start-up stage 42
3.5.2 Operational stage 43
3.5.2.1 Positive impacts 43
3.5.2.2 Adverse impacts 43
CHAPTER 4 MITIGATION MEASURES OF NEGATIVE ENVIRONMENTAL IMPACTS 58
4.1 PRE-CONSTRUCTION PHASE 58
4.2 CONSTRUCTION PHASE 58
4.2.1 Mitigation measures of air pollution 59
4.2.2 Mitigation measures of noise pollution 59
4.2.3 Mitigation measures of water pollution 59
4.2.4 Mitigation measures of pollution caused by solid waste 60
4.2.4.1 Domestic solid waste 60
4.2.4.2 Dredged sludge and excavated soil 60
4.2.5 Mitigation measures on the cultural work 60
4.3 OPERATION PHASE 61
4.3.1 Mitigation measures for operation phase 61
4.3.1.1 Grit chamber + screen: 61
4.3.1.2 Trickling filter 61
4.3.1.3 Facultative lagoons 62
4.3.1.4 Anaerobic lagoon 62
4.3.2 Method for mitigation environmental impacts caused by solid waste 63
4.3.2.1 Solid waste 63
4.3.2.2 Sludge 63
4.3.3 Eliminate the impacts of micro-organisms on workers 63
4.3.4 Mitigation measures for cultural resources 63
4.3.5 Mitigation measures for the receiving water in the operation phase 64
4.3.6 Emergency operating plan 64
4.3.7 Other measures 65
4.3.7.1 Plant site 65
4.3.7.2 Storage facilities 65
4.3.7.3 Illumination 65
4.3.7.4 Ventilation 65
4.3.7.5 Fire protection 66
4.3.7.6 Hazardous operation 66
4.3.7.7 Working accidents 66
4.3.7.8 General safety design consideration 66
CHAPTER 5 COMMITMENT ON ENVIRONMENTAL PROTECTION 67
5.1 IN THE PRECONSTRUCTION AND CONTRUCTION PHASE 67
5.2 IN THE OPERATION PHASE 67
5.3 COMMITMENT TO FOLLOW ALL VIETNAMESE STANDARDS ON ENVIRONMENT 67
5.4 ENVIRONMENTAL MANAGEMENT 67
CHAPTER 6 ENVIRONMENTAL MANAGEMENT PLAN 69
6.1 ENVIRONMENTAL MANAGEMENT PROGRAM 69
6.1.1 Impacts and mitigation measures 69
6.1.2 Mitigation measures 69
6.1.2.1 Design phase 69
6.1.2.2 Construction phase 70
6.1.2.3 Operation phase 70
6.1.3 Environmental monitoring program 70
6.1.3.1 Environmental monitoring program 70
6.1.3.2 Project performance indicators 70
6.1.3.3 Monitoring implementation of mitigation measures 70
6.1.3.4 Overall regulatory monitoring 71
6.2 PROJECT ORGANIZATION FOR ENVIRONMENTAL MANAGEMENT 74
6.3 CAPACITY DEVELOPMENT AND TRAINING 75
CHAPTER 7 ESTIMATION OF THE COST OF THE ENVIRONMENTAL FACILITIES 78
CHAPTER 8 COMMUNITY CONSULTATION 79
CHAPTER 9 INSTRUCTION OF SOURCES OF DATA AND ASSESSMENT METHODS 81
9.1 SOURCES OF DATA 81
9.1.1 References 81
9.1.2 Sources of Documents, Data prepared by the Project Owners 82
9.2 METHODS APPLIED DURING THE IMPLEMENTATION OF EIA 82
9.2.1 Field Survey Method 82
9.2.2 Identification Method 82
9.2.3 Quick Assessment Method 83
9.2.4 Forecasting Method 83
CONCLUSIONS AND RECOMMENDATIONS 84
CONCLUSIONS 84
RECOMMENDATIONS 85
LIST OF FIGURES
Figure 1-1: Location of the CEPT plant 8
Figure 1-2: General plan of the CEPT 10
Figure 1-3: Scheme of the Alternative 1 15
Figure 1-4: Scheme of the Alternative 2 16
Figure 1-5: Scheme of the Alternative 3 17
Figure 1-6: Location of the main outlet 19
Figure 2-1: Anemometric results at Quy Nhơn station 22
Figure 2-2: The representative land form at the area location (core zone of Phase1) 26
Figure 2-3: The artifical lakes to raise seafood (core zone of Phase 1) 26
Figure 3-1: The location of the temporary outlets of CCESP 33
Figure 3-2: Diagram of construction of CEPT plant and its environmental impacts 34
Figure 3-3: Environmental impacts of alternative 1 35
Figure 3-4: Environmental impacts of alternative 2 36
Figure 3-5: Environmental impacts of alternative 3 37
Figure 3-7: Waste generated from the treatment facilities in the Alt 2 53
Figure 3-8: Waste generated from the treatment facilities in the Alt 3 54
Figure 6-1: Project organizational structure for Environmental Management 74
LIST OF TABLES
Table 1-1: The relationship between the CEPT project and the other components of the Quy Nhon CCESP project 6
Table 1-3: Proposed schedule for the project 7
Table 1-4: Estimation of served population in the project area by 2023 11
Table 1-5: Designed capacity and BOD loading of the plant 11
Table 1-6: Components and characteristics of domestic wastewater 11
Table 1-7: Land demands for three alternatives 18
Table 1-8: Summary of investment cost of three alternatives 18
Table 2-1: Characteristics of Hà Thanh River basin 23
Table 2-2: Results of the air monitoring at Quy Nhơn City 24
Table 2-3: Water quality of Hà Thanh River at the proposed outlet of CEPT plant (12/2005-01/2006) 24
Table 2-4: Source of revenue 28
Table 2-5: Types of qualification gained by the heads of the household 28
Table 2-6: Total volume of solid waste in Quy Nhơn City (2004) 31
Table 2-7: The standard of water supply for Quy Nhơn City by 2020 32
Table 2-8: Water demand for Quy Nhơn City 32
Table 3-1: Land demand for the CEPT plant 38
Table 3-2: Summary of affected households in site clearance 38
Table 3-4: Emission loading of air contaminants in the construction phase 39
Table 3-6: Adverse effects of three alternatives in the acclimating phase 43
Table 3-7: Inputs of the model 44
Table 3-8: Baseline data of Hà Thanh River in the model 44
Table 3-9: Summary of distance (km) from the effluent outlet to recover the baseline values at high tide 45
Table 3-10: Summary of distance (km) from the effluent outlet to recover the TCVN5942:1995 values at high tide 45
Table 3-11: Summary of distance (in km) from the effluent outlet to return the baseline values for low tide 45
Table 3-12: Summary of distance from the effluent outlet to recover the TCVN5942:1995 values for low tide 46
Table 3-13: Potential accidents in the operational activities of secondary treaments 47
Table 3-14: Location of potential cause of odor in the wastewater treatment system (US.EPA,1985) 49
Table 3-15: Waste generated in the wastewater treatment plant 55
Table 3-16: Risk assessment in contacting with microorganism in wastewater or sludge 56
Table 4-1: Mitigation measures for operational incidents in trickling filters 61
Table 4-2: Hazards and dangers leading to emergencies 64
Table 6-1: Summary of impacts, meitigation measures and monitoring plan 71
Table 6-2: Responsibility of the parties in the environmental management program 75
Table 7-1: Estimated Budget Costs for EMP Implementation (in VND) 78
INTRODUCTION
1 INTRODUCTION
The project of constructing a wastewater treatment plant using Chemical Enhanced Primary Technology (CEPT) Wastewater Treatment Plant Project –Quy Nhon City (Binh Dinh) is a component of CCESP Program funded by the World Bank and implemented in three cities: Dong Hoi City, Nha Trang City and Quy Nhon City. CEPT project in Quy Nhon City is the pilot project for wastewater treatment sponsored by non-refundable aid of Global Environment Funds (GEF) who’s priority strategy is “promoting policy reform and pollution control methods”, “piloting, experimenting and multiplying new methods of pollution reduction”. It is sponsored by GEF to prove the effect in applying Chemical Enhanced Primary Treatment (CEPT) in Vietnam, with a desire that the treatment technology may be applied in other urban areas.
2 LEGAL AND TECHNICAL DOCUMENTS
1 Legal base
1 Requirements of Vietnamese legislation in Environmental Impacts Assessment
- Vietnam Environmental Protection Law (29/2005/L/CTN), approved by the Parliament of Social Republic of Vietnam on 29/11/2005 and implemented by 01/07/2006.
- Water Resource Law approved by the Parliament of Social Republic of Vietnam on 29/11/2005 and implemented by 01/06/1998.
- Decree 68/CP (01/11/1996) which provides detailed guidance of implementing Resource Law.
- Decree 52/1999/ND-CP (08/07/1999), approved by the Government on the regulations of Management of Investment and Construction.
- Decree 67/2003/ND-CP (13/06/2003), approved by the Government on the Environmental Protection Fee of Wastewater.
- Decree 04/2007/ND-CP (08/01/2007), approved by the Government on the amendments of Decree 67/2003/ND-CP
- Decree 68/2005/ND-CP (20/05/2005), approved by the Government on Chemical Safety
- Decree 80/2006/ND-CP (09/08/2006), approved by the Government on detailed guidance of implementing Vietnam Environmental Protection Law
- Decree 81/2006/ND-CP (09/08/2006), approved by the Goverment on administrative punishment in environmental protection.
- Decree 59/2007/ND-CP (09/04/2007) on Management of Solid Waste
- Decision 22/2006/QD-BVMT (18/12/2006), approved by Minister of Ministry of Natural Resources and Environment on the enforcement of using TCVN regulations on environment issues.
- Decision 23/2006/QD-BTNMT (26/12/2006), approved by Minister of Ministry of Natural Resources and Enviroment on List of Hazardous Wastes.
- Series of TCVN issued by Minister of Science, Technology and Enviroment in accompanion with Decision 35/2002/QD-CP.
- Circular letter 08/2006/TT-BTNMT (28/09/2006), issued by the Ministry of Natural Resources and Environment on the guidance of strategic environmental impact assessment, environmental impact asessment and commitment of environmental protection
- Circular letter 125/2003/TTLT-BTC-BTNMT (18/12/2003) on the guidance of implementing Decree 67-CP of the Environmental Protection Fee of Wastewater.
- Circular letter 12/2006/TT-BCN (12/12/2006) issued by the Ministry of Industry on guidance of implementing Decree 68/2005/ND-CP (20/05/2006), issued by the Government on Chemical Safety.
- Circulation letter 12/2006/TT-BTNMT (26/12/2006) issued by the Ministry of Natural Resource and Environment on requirements and procedures of registration for management of hazardous waste
2 Requirements of World Bank on Environmental Impact Assessment
- Environmental Assessment – Procedure/ Regulations (OP/BP 4.01)
- Natural Habitat (OP 4.04)
- Cultural Resources (OP 4.11)
3 Local documents
- Official letter No.1018/UBND-XD (11/04/2007), issued by the Binh Dinh People’s Committee on the location of Wastewater Treatment Plant 1B (CEPT)
- Official letter No.2417/UBND-XD (08/08/2007), issued by the Binh Dinh People’s Committee on requirements of the quality of treated water in accordance with TCVN 7222-2002.
2 Technical documents in Environmental Impact Assessment (EIA)
Technical documents used in this report included technical reports related to the project which were provided by the investor and the data on the environmental conditions within the concerned area which were provided by the Binh Dinh Department of Natural Resources and Environment.
- Assessment of Sources of Air, Water, and Land Pollution – A Guide to Rapid Source Inventory Techniques and their Use in Formulating Environmental Control Strategies – WHO, 1993.
- Report on Actual Status of Binh Dinh Provincial Environment 2005. Binh Dinh Provincial Department of Natural Resources and Environment (DoNRE), 2006
- Report on Econo-Social, Security and Natural Defense in 2006 and duties in 2007, Nhon Binh Ward PC, 2007
- Report on Status of Economic, Society and National Security – 2006 and the Duties in 2007, Nhon Binh Ward People’s Committee, 2007.
- Climate and Hydrology Characteristics of Binh Dinh Province, Scientific Study Report, directed by Master Nguyen Tan Huong, Binh Dinh Provincial Department of Science and Technology, 2004 to 2005.
- General Plan Adjustment for Quy Nhon City – Binh Dinh Province to 2020 approved by the Government on 1st June, 2004.
- Orientation for the Development of Drainage for Viet Nam Urban untill 2020 – Ministry of Construction (MOC).
- Binh Dinh Province’s Geography Book (website of Binh Dinh Provincial Department of Science and Technology), Binh Dinh Provincial Department of Science and Technology.
- 2006 Yearbook Statistics, Binh Dinh Provincial Department of Statistics, 2007
- Operation of Municipal Wastewater Treatment Plants. Water Environment Federation (WEF), 1996. USA
- Principles of Surface Water Quality Modeling and Control. Thomann R.V and Mueller J.A, 198. New York
- Technical Document of WHO and WB on preparation of EIA Report.
- Restoration of Con Chim Ecosystem, Environment Protection Magazine, No5/2003, Hoang Lan, Binh Dinh Science and Technology Department (now is Science and Technology Department).
- Wastewater Engineering, Metcalf and Eddy, 2001, 2003
- Wastewater Treatment at Ha Thanh Site in Quy Nhon, Frédéric Chagnon & Donald R.F. Harleman; Ralph M. Parsons Laboratory, Department of Civil & Environmental Engineering, Massachusetts Institute of Technology.
- Project Survey Report, Flow Impact Assessment Report, Flood Discharge in Ha Thanh River North Area, Quy Nhon City, Binh Dinh Province, Hydrography Research Center, Hydrometeorology Institute, Project Team Leader, Dr. La Thanh Ha.
- Construction Survey Report for CEPT Wastewater Treatment Plant – Quy Nhon City Environment and Sanitation Sub-project – Grontmij¦ Carl Bro a/s in collaboration with Carl Bro Vietnam and WASE, September 2007
- Inception Report of Quy Nhon City Environment and Sanitation Sub-project (Wastewater Treatment Plant under Step 1 Technology, strengthening chemical) Grontmij Carl Bro a/s - March, 2006
- Environmental Report – Coastal Cities Environmental Sanitation Project- Quy Nhon City Sub-project, The Louis Berger Group, Inc Joint Venture with Nippon Koei Co., Ltd. May 2006.
- Investment and Construction Project of CEPT Wastewater Treatment Plant – Quy Nhon City Environment and Sanitation Sub-project – Grontmij¦ Carl Bro a/s in collaboration with Carl Bro Vietnam and WASE, September 2007
- Resettlement Plan for CEPT Wastewater Treatment Plant – Quy Nhon City Environment and Sanitation Sub-project – Grontmij¦ Carl Bro a/s in collaboration with Carl Bro Vietnam and WASE, September 2007
- Basic Design Statement of CEPT Wastewater Treatment Plant – Quy Nhon City Environment and Sanitation Sub-project – Grontmij¦ Carl Bro a/s in collaboration with Carl Bro Vietnam and WASE, September 2007
3 ORGANISATION
1 Environmental screening
Although this project is funded by the Global Environmental Funds (GEF), it is managed by the World Bank. It must follow the regulations of World Bank on the policies of environmental protection. Therefore, the procedure of environmental impact assessment is defined in the WB Guidance on Policy of Environmental Safety (OP 4.01 – Environmental Assessment).
Every project is expected to have environmental screening (OP 4.01) in order to determine the type of the EIA report. Projects funded by WB are divided into four categories (A, B, C, D) with regards to the nature, location, sensitivity and scale of the projects in accompanied with the nature and scale of potential environmental impacts of the projects. The CEPT project is a environmentally beneficial project and was designed to eliminate the adverse environmental impacts. However, after considering the location and activities of the projects, there are some specific issues that must be considered.
- It is located in the planned North-West Industrial and Urban Zone of the Quy Nhon City
- Near the mouth of the sea and Thi Nai Lagoon
- Excavating, digging, covering, changing the flooding channel and other environmental conditions
This project was classified as A-project which was agreed by the WB experts in the workshop on 15-17/07/2007. Therefore, a full report of EIA was required. It is also in accordance with the Vietnamese regulations, in particular the Decree 80/2006/ND-CP (09/08/2006), approved by the Government on detailed guidance of implementing Vietnam Environmental Protection Law (Annex – The concentrated domestic wastewater treatment plant with the capacity over 1000m3/day).
2 Report contents and form
The main contents of this report include:
- Synthesize and assess the information on environmental baseline conditions which include quality of surface water, groundwater, atmosphere, solid waste management and biodiversity.
- Recognise, assess and predict the potential impacts on the ambient environment.
- Propose the mitigation measures (technical, managerial and monitoring measures) in order to mitigate adverse impacts and schedule of environmental monitoring.
3 Research team
This EIA Report was done by an independent research team. The members of research team are listed as following.
1. Dr. Nguyễn Phước Dân EIA Specialist
2. Dr. Lê Hoàng Nghiêm Specialist on Modelling
3. MA. Võ Thị Phương Trâm Environmental Assessment
4. Eng. Phạm Hoàng Lâm Environmental Engineer
PROJECT SUMMARY AND DESCRIPTION
1 GENERAL INTRODUCTION
1 Project implementation situation
In the general context of overall CCESP program, objectives of each Project under the program were concentrated more particularly. These objectives interpreted in “Summary Report” prepared for Quy Nhon City Environmental Sanitation Project (April/2005), “Pre-feasibility Study Report” and especially in Report “Wastewater Treatment Plant in Ha Thanh, Quy Nhon City” prepared by members of Massachusetts Institution, June 2005.
CEPT project in Quy Nhon City is the pilot project for wastewater treatment sponsored by non-refundable aid of Global Environment Facility (GEF), the priority strategy of this organisation is “promoting policy reform and pollution control methods”, “ piloting, experiment and multiply new method to reduce pollution generated from the mainland. This project is sponsored by GEF to prove the effects in of application of applying Chemically Enhanced Primary Treatment (CEPT) in Vietnam, with a desire that the treatment technology may be applied in other urban areas.
Following the above mentioned relevant studies, the Contract Agreement for Technical Assistance was awarded to the Grontmij Carl Bro a/s for the construction of CEPT Wastewater Treatment Plant, Quy Nhon City and the Contract Agreement was signed off on 15 March 2007. The major content of the Contract is to prepare the investment and construction project, detailed engineering design, bidding documents and the other supporting documents for the Wastewater Treatment Plant to which the CEPT technology will be applied. The Project’s Inception Report was completed on 16 March 2007. The first submission of Bids was submitted by Grontmij Carl Bro a/s for the Wastewater Treatment Plant investment and construction project (FCIR), and the revised version was submitted on 29 September 2007. This EIA report is a part of the above mentioned contract agreement for the technical assistance.
2 Project principles and objectives
1 Project objectives
- To improve the environmental sanitation condition, healthy for local residents through out building, upgrading, expanding wastewater collection system, building wastewater plant ensured in meeting allowance standard before discharge environment, simultaneously propose household sanitation improvement through out rotation fund.
- Be a pilot model for concentrated Wastewater Treatment Plant for urban of the city.
2 Project principles
- In conformity with general development programming of the city up to 2020 (approval of government in 06/2004);
- To contribute economic development and eliminate hanger and reduce poverty;
- Participation of community
- Design specification shall be in accordance with the capacity and demand of community;
- To execute the work under approval of consultants and conform to the procedure of Vietnam government and the World Bank.
- Upgrading infrastructure not only to meet the imperative and short-term demands of community, but also to facilitate for stable development process in the future.
2 PROJECT DESCRIPTION
1 Project title
Chemically Enhanced Primary Wastewater Treatment Plant - Quy Nhon City Environmental Sanitation Sub-project
2 Investors
Binh Dinh Provincial People’s Committee
3 The design consultants
Grontmij-Carl Bro a/s combined with Carl Bro Vietnam and WASE
4 Total investment capital and capital framework
The construction of CEPT Wastewater Treatment Plant is a part of the Coastal Environmental Sanitation sub-project of Quy Nhon City which contained 6 components and project of the CEPT Wastewater Treatment Plant is in component 2. Total investment capital for the environmental sanitation project of Quy Nhon is showed on table 1-1.
Table 1-1: The relationship between the CEPT project and the other components of the Quy Nhon CCESP project
|Component |Content |
| Drainage and Wastewater Collection |Constructing and replacing the main drainage system with references to scale and location |
| |Dredging and repairing the existing sewers |
| |Dredging and upgrading the regulative lakes Bau Sen, Dong Da and constructing a new lake – |
| |Bong Hong |
| |Constructing the outlet gates and water intrusion gateways |
| |Constructing the wastewater collection system, seperating wells, culvets and pumping |
| |station |
|Wastewater Treatment Plant |Constructing three wastewater treatment plants |
|Solid Waste Management |Expanding and improving the Long My landfill (30ha) |
| |Providing the equipments for collecting solidwaste in order to increasing the collection |
| |rate. |
|Resettlement and Site Clearance |- Constructing the resettlement site 5 ha; compensating and displacing 200 households to |
| |clear the site, construct the plants and ensure the safe buffer distance. |
|Fund for sanitating household conditions |- Households without toilets can borrow a loan of 3.000.000 VND per household to build a |
| |new toilet. The duration of lending is 24 months with the interest of 0.5% per month. |
|Strenthening the capacity and human resources in | |
|order to assist the whole project | |
In terms of investments in CEPT project, because of its large-scale construction and limited budget from the GEF , only a part of the project is funded by the GEF . Thus, avoiding investment issues, the project was phased to meet 5 million USD limitation of GEF. This project is divided into two phases.
- Phase 1 from 2007 to 2013. Phase 1 is phased into two, Phase 1A will implement on basis of using 5 million USD sponsored by GEF and Phase 1B will be implemented later by another capital source, for example loan from the World Bank.
- Phase 2 from 2013 to 2023. Phase 2 is the expand project in the future will be implemented by another capital source.
Total investment capital for phase 1 of CEPT Wastewater Treatment Plant is sponsored from non-refundable aid of GEF combined with reciprocal capital of Vietnam government.
Table 1-2: Structure of capital investment for the CEPT Project – Phase 1
(Exchange rate: 1USD = 16,100 VND)
|Item |GEF (USD) |Vietnam (USD) |
|Capital Investment |5,394,371.00 |2,512,359.00 |
|Percentage |68.23% |31.77% |
|Total |7.906.730,00 |
(Source: Investment and Construction Project of CEPT Wastewater Treatment Plant – Quy Nhon City Environment and Sanitation Sub-project – Grontmij¦ Carl Bro a/s in collaboration with Carl Bro Vietnam and WASE, September 2007)
5 Project Implementation Progress
The progress of project is shown in tables 1-4.
Table 1-3: Proposed schedule for the project
|Time |Activities |
|05/2008 |Sign the contract to receive the funding from GEF |
|06/2008 |Funding becomes effective |
|08/2008 |Implement the first module (site preparation) |
|09/2009 |Implement the second module (plant construction) |
|10/2011 |Operate the plant |
(Source: Investment and Construction Project of CEPT Wastewater Treatment Plant – Quy Nhon City Environment and Sanitation Sub-project – Grontmij¦ Carl Bro a/s in collaboration with Carl Bro Vietnam and WASE, September 2007)
3 PROJECT LOCATION
1 Proposed locations
In pre-feasibility analysis stage, two potential sites were assessed. Site 1 was determined in stage of selecting consultant, the area of this site is 7 ha (including 300m buffer zone under TCVN 7222:2002) or 3 ha ( not including buffer zone) in the East and the South. It is bordered with industry zone in the West and shrimp and fish hatching lagoon in the North. Site 2 has an area of 91 ha (containing buffer zone) or 12,8 ha (without buffer zone). Because the area of site 1 is limited (especially expanding in phase 2) and closed to residential area. Site 2 is proposed for building plant. On 8-10/04/2007, Project 2 approved by the assessment mission of World Bank.
2 Site selection
CEPT Wastewater Treatment Plant is proposed to be constructed in Nhon Binh ward, Quy Nhon City. It is located in the industrial zone and Quy Nhon City North-Western urban area development planning area. Location map of project is showed on Figure 1-1.
[pic]
Figure 1-1: Location of the CEPT plant
In general, project location belongs to the former agricultural area, projected to develop in to a new industrial zone and town. In the future, (according to Quy Nhon City Master Plan), some new streets will be re-planned and re-built in this area.
4 PROJECT SCOPE
1 Determination of the necessary demand of project
Thanks to the changes in terms of the building socio-economic policy of the Party and State, Party Committee and Binh Dinh province’s people, Quy Nhon City comes into a comprehensive reform period, economic activities, especially in construction and investment sectors. Together with the socio-economic development, the improvement and upgrading process of existing urban, expansion of new urban areas, the planning and construction of the concentrated industrial zones have been implemented strongly.
To promote the potential of the City, an environment sanitation project of Quy Nhon City was signed between the Vietnamese government and World Bank. In implementing phase, feasibility study report must be prepared. This Feasibility Study Report should be in accordance with the Decision No 52/1999/ND-CP dated 08/7/1999, Decision No 07/2003/ND-CP dated 30/01/2003 by Prime Minister and Terms of References (TOR) issued in February, 2004 relating the preparation of the Pre-feasibility Study Report of Quy Nhon City Sub-project, Binh Đinh province.
Quy Nhon City Environmental Sanitation Sub-project is a part of Coastal Cities Environmental Sanitation Project sponsored by the World Bank, including Quy Nhon, Nha Trang and Đong Hoi Cities. The objective of CCESP is to:
a) Sustainably improve health of community
b) Increase economic development by means of minimizing flood condition, improving urban environment, capacity building and sustainable development about finance for sanitation and drainage companies in Quy Nhon, Nha Trang, Đong Hoi.
CEPT Wastewater Treatment Plant project in Quy Nhon sponsored from non-refundable aid of Global Environmental Funds (GEF), with the priority strategy is to “promote policy reform and environmental control means” and to “prove, experiment and multiply innovative model to minimize land pollution”. Sub-Project sponsored to prove the effective of using chemical enhanced primary technology in Vietnam, with the expectation that this technology will be applied in other areas as well. In technical documents about the treatment process, satisfactory results were recognized in the report, especially, relating to get rid of BOD5, SS and Nutrients.
2 Technical standards
Vietnamese Standard TCVN 7222:2002 was applied for the Wastewater Treatment Plant under Chemical Enhanced Primary Technology (CEPT) under Official Letter No 241/UBND-XD dated 08/08/2007 by Binh Dinh Provincial People’s Committee regarding the design of CEPT Wastewater Treatment Plant in accordance with TCVN 7222-2002.
3 Output capacity and treatment requirements
1 Capacity
Capacity of plant is determined based on: (a) number of residents existed in the drainage basin of the collection network by the designed year, and (b) drainage standard per one resident (Litre/person/day).
Drainage basin covers ten wards with an estimated population of 175000 residents by 2023. Drainage standard is calculated on the ground of water supply standard which is about 80% water supply for a person in 2023. In addition, treatment plant capacity also takes into account the permeable and overflowed, taking 25% of the total water sewage.
Serviced population of plant is predicted (Table 1-5) and based on population of 2003 with the rate of population growth is 1.5%/per year. Population of Nhon Binh, Binh Phu, and North Ha Thanh wards were calculated based on general planning documents of Quy Nhon City by 2020 with the range to be serviced is 25%. Population of Ly Thuong Kiet, Tran Phu and Ngo May wards were calculated based on drainage basin data.
To create favorable condition for the future expansion of CEPT Wastewater Treatment Plant, right in the first time of Phase 1A, major service functions of CEPT Wastewater Treatment Plant will be designed well to expand the plant in Phase 1B in order to save cost. Time duration proposed for the construction of phase 1A and 1B is five years, since such necessary shortening is limited in the non-refundable aid of GEF, which requires expanding the plant in a short-time in order to create a safety working conditions for a long time for the treatment components of plant.
[pic]
Figure 1-2: General plan of the CEPT
Table 1-4: Estimation of served population in the project area by 2023
| |Ward |Population (capita) |Estimation of population (capita) |Percentage of |Estimation of served population |
| | | | |served population|(capita) |
| | |2003 |Rate |
| | | |Phase 1A |Phase 1B |Phase 2 |
| | | |2007-2013 |2013-2018 |2018-2023 |
|1 |Population |Capita |58,333 |116,667 |175,000 |
|2 |Drainage criteria |l/capita/day |120 |120 |160 |
| |(~80% water supply criteria) | | | | |
|3 |Designed flow rate |m3/day |7.000 |14.000 |28.000 |
|4 |Infiltration flow rate |m3/day (25% of the designed flow rate) |1.750 |3.500 |7.000 |
|5 |Unstable coefficient | |1.75 |
|6 |Maximum flow rate |m3/day |12.250 |24.500 |49.000 |
|7 |Maximum daily flow rate |m3/day |14.000 |28.000 |56.000 |
|8 |Organic loading |gBOD5/capita.day |40 |40 |50 |
|9 |Total organic loading |KgBOD5 /day |2.300 |4.700 |8.800 |
|10 |BOD concentration |mg/l |340 |340 |340 |
2 Components and characteristics of the influent
Wastewater Treatment Plant will receive wastewater mainly from residential areas belong to drainage basin and receive sludge from septic tanks. Components and characteristics of the wastewater is shown on table 1-6.
Table 1-6: Components and characteristics of domestic wastewater
|Parameter |Unit |Value |
|pH |- |5-9 |
|BOD5 |mg/l |340 |
|SS |mg/l |320 |
|Total nitrogen |mg/l |80 |
|Total phosphorus |mg/l |12 |
|Oil and grease |mg/l |120 |
|Coliform |MPN/100ml |108 |
(Source: Metcaft and Eddy, 2000)
3 Effluent standards
In accordance with the Official Letter Ref. 2417/UBND_XD dated 08/08/2007 by Binh Dinh Provincial People’s Committee for CEPT Wastewater Treatment Plant design under Vietnamese standard TCVN 7222-2002, Wastewater Treatment Plant was designed with the quality of discharge water after treatment gaining the limit value of standard. General requirement for environment against concentrated Wastewater Treatment Plant TCVN 7222-2002.
4 Description of the outline of WWTP
The project is now under selection of a feasible wastewater treatment process. Three proposed wastewater treatment processes are shown in Figure 1-3, 1-4 and 1-5. These options have the same preliminary treatment (screens) and advanced primary treatment (mixer, floculator and anaerobic settling pond) and sludge treatment (anaerobic settling pond). These alternatives are different in term of secondary treatment. They are Alternative 1- Facultative ponds, Alternative 2 -Trickling filters, and Alternative 3 - Oxidation ditches
5 Preliminary and primary treatment
Raw wastewater from the end of the sewerage system enters into a pump sump. There are two bar screens in the pump sump: (a) a coarse bar screen with opening of 50 mm followed by (b) a medium bar screen with opening of 10mm, to remove rags, leaves, papers, plastic bags, etc. Three submersible pumps with capacity from 60 l/s to 120 l/s are installed in the pump sump.
The wastewater is pumped to a rapid mixer, into which alum solution is dosed. Alum flocs are formed at a flocculator with hydraulic retention of 16 minutes. Anion polymer as coagulant aid is dosed into the flocculator to enhance the size of flocs and thus improving settling velocity of flocs at the anaerobic settling pond.
Except the function of sedimentation, this pond is in charge of settled sludge stabilization and BOD removal of wastewater by natural anaerobic process. The total BOD removal is about 60%. The pond with depth of 4.0 m facilitates a full anaerobic condition. Its hydraulic retention time is 84 hours. The design BOD loading rate is 90 kg BOD5/1000 m3/day. Thus, it is run at low loading rate of less than 200 kg/1000m3/day in order to mitigate odour production.
The pond bottom and vertical walls of one meter high from the bottom are made of concrete. Those are used for sludge treatment, water decant and sludge mixing for composting on site. Three sloped walls (V:H = 1:3) are lined with impermeable HDPE layer. The remaining side with slope V:H of 5:1, which is made of concrete is used for loading sludge out the pond by vehicles.
The suspended solid removal of the pond is about 60%. Except septage and primary sludge, this pond also receives the waste sludge from the secondary treatment. The settled sludge is stabilized for at least two years. The biodegradable organic content and pathogens will decrease significantly. The stabilized sludge will be dredged after two or four years of operation. Water in one of two ponds will be decanted in dry season. The water level is lowered to one meter deep. Then the sludge is dewatered by sunlight drying on site. The sludge cake is mixed to compost at the pond bottom and finally, the compost is loaded to a fertilizer production company.
In the phase II, the sludge treatment will be done sequent for four anaerobic settling ponds. Long sludge retention time of the ponds ensures high stability of the sludge. Long duration between two sludge dredging will reduce job load of operators. Operation units in primary treatment such as anaerobic settling pond, sludge stabilization and sludge mixing do not require energy and chemical consumption and less labour, which are met requirement of the organization receiving the WWTP. The effluent of anaerobic settling ponds is conducted to the secondary treatment.
6 Secondary treatment
Three alternatives of secondary treatment were proposed in terms of 1) the available land area, 2) The effluent standards TCVN 7222, and 3) low operation and maintenance costs. The primary treatment with chemical enhancement (CEPT technology) will get high SS, BOD and pathogen removals and thus, influent of the secondary treatment will be more stabilized. Three alternatives of the secondary treatment are describes as follows:
Alternative 1: Cascade aeration ( facultative pond
Based on difference of elevation between facultative pond and anaerobic settling pond, cascade aerators will be set-up followed by the facultative pond. In cascade aerators, the air is dispersed into the water through water stream jumps to stairs in series. Thus, DO will increase prior to wastewater come to the facultative pond. The cascade aerator includes series of concrete stairs. Each stair is 1.0 meter wide, 6 meter long and 0.6 meter high. Eight stairs form weirs facilitate oxygen saturation that enhances BOD removal and reduce odor problem. This aeration use elevation difference between primary and secondary treatment systems therefore, energy consumption is not necessary.
The facultative ponds (2+2) is arranged in two parallel lines, each line includes two ponds in series. The first pond has larger area and receives higher organic loading. The facultative ponds of 2.0 m deep and 1.5 m deep will be constructed in phase 1 and phase 2, respectively. The sequent others are more shallow to maintain aerobic condition through whole pond depth. The HRT of pond system in this phase is 15,4 days, based on organic loading less than 200kg/ha/day. All facultative ponds are lined with HDPE layer. The slope of pond is 3:1. The BOD5 removal efficiency is 50-70% at which effluent BOD5 is less than 30 mg/l (the limited value of effluent Standards TCVN 7222-20002). In facultative ponds, it is hard to control algae in effluent and this problem can contribute to increase BOD5 and SS concentration than estimated values. Therefore, algae control should be further studied. However, the advantages of this option are (a) not requiring electric and chemical consumption, (b) easily operation and (c) less requirement of skilled operator. Those are the necessary requirements of the city authorities.
Alternative 2: Cascade aeration ( trickling filter ( secondary clarifier
As the same in alternative 1, Cascade aeration is used to increase DO concentration in wastewater before conducting to trickling filter. Trickling filter used attach-growth process that has stable efficiency, low power demand and high ability of load shock withstanding. The wastewater from Cascade aerator and returned water from secondary clarifier at return ratio of 300% are collected to pump sump. The mixture is pumped to the top of the trickling filter and distributed to the filter plastic media by jet distributor with motor. Wastewater is trickled through filter media, on which bacterial film is grown. The organic matters in term of BOD5, are stabilized by bacteria. The biofilm sloughed off media will settle down to clarifier bottom.
This process requires power for running return water pump. The estimated power is about 50kWh (phase 1). It does not need skilful worker for system operation, biofilm cleaning and periodical maintenance. In operational side, it is not necessary to frequently control the process except selecting the adequate return rate. Pump with two speeds can be used so that it is not necessary to adjust the return water rate.
In the secondary sedimentation tank, sludge scrapper collected the settled sludge into the sludge hopper at the bottom. Sludge is pumped out to the influent pump sump and settled down at the anaerobic settling pond. This alternative does not require chemicals, skilful operators and high electric demand. Therefore, the option is also proper to the requirements of organization receiving WWTP.
Alternative 3: oxidation ditch + secondary clarifier
Wastewater from primary treatment flows to the oxidation ditch and mixed with returned sludge in the ditch. Oxidation ditch, which activated sludge process is used has high treatment efficiency and easy in combination of nitrogen removal. After HRT of 18 hours, the mixed liquor of sludge and wastewater will flow to the secondary clarifier for gravity separation of bioflocs. The excess sludge is pumped to the influent pump sump and settled at the anaerobic settling pond. Sludge from secondary sedimentation tank is returned to the ditch to maintain high biomass concentration. The biomass concentration is about 3000 mg SS/L. The oxidation ditch requires high power and skilful operator. The option C produces effluent quality better than those of two above options. The process requires frequent checks/tests on sludge characteristics, biomass concentration (MLSS) and sludge volume index (SVI). The excess sludge is daily removed to keep SRT of 20 days. Two oxidation ditches are in parallel operation. To minimize the construction area, the ditch is designed in U shape (width x depth = 6m x 3m) with aeration devices that are installed at two ends of the ditch for mixing and diffusing oxygen. The estimated power for the process is 240 KW (phase 1).
7 Effluent disinfection before discharge into receiving water
According to Vietnamese Effluent Standards TCVN 7222-2002, the disinfection is necessary. However, the standards does not give limited value of pathogen. Maybe, significant remove of pathogen is obtained by primary and secondary treatment. Because the limit value of total coliform number is not available, the disinfection of WWTP effluent has not decided yet. If the local authority (Department of Environment and Natural Resource of Binh Dinh province) assumes that disinfection is necessary and a limited value of pathogen is given, the disinfection facility is added as total coliform removal of the primary and secondary treatment is not met. To have simple and effective treatment process, it is necessary to consider the application of maturation ponds after secondary treatment for disinfection and advanced treatment such as nitrogen removal and algae control.
The depth of maturation ponds for disinfection is 1.0 m, the bottom is lined with HDPE layer to prevent plant growth in bottom and it is convenient for bottom cleaning. The pond is designed with the length:widh ratio of 4:1 and there are at least 3 ponds in series. The minimum HRT of maturation pond system is 3 days, based on the average wastewater flow rate in dry season (ADWF). The specific size of pond depends on real wastewater discharge.
Chlorination is only used if the area is limited or strict effluent standards. Because chlorination requires higher chemicals and power demands, skilled operators, separate store. Therefore, chlorination is only taken into consideration as maturation ponds could not used.
[pic]
Figure 1-3: Scheme of the Alternative 1
[pic]
Figure 1-4: Scheme of the Alternative 2
[pic]
Figure 1-5: Scheme of the Alternative 3
4 The land requirements and cost estimation for three alternatives
The land requirements for each alternative are presented in the table 1-7.
Table 1-7: Land demands for three alternatives
|No. |Alternative |Core Area |Buffer Zone |Total Area |
| | |hectare (ha) |hectare (ha) |hectare (ha) |
| | |Phase 1A+1B |Phase 2 |Total |
| | |(USD) |(USD) |(USD) |
|Alternative 1 – Facultative Pond |
|1 |Construction and equipment cost |4,890,551 |2,501,003 |6,863,608 |
|2 |Land acquisition and resettlement cost |3,169,898 |0 |0 |
|3 |Construction supervision cost |400,000 |180,000 |600,000 |
|4 |Contingency |846,045 |268,100 |746,361 |
| |Total cost |9,306,494 |2,949,103 |8,209,969 |
|Alternative 2 – Trickling filter |
|1 |Construction and equipment cost |4,537,746 |1,794,588 |5,710,238 |
|2 |Land acquisition and resettlement cost |1,834,357 |0 | |
|3 |Construction supervision cost |400,000 |180,000 |600,000 |
|4 |Contingency |677,210 |197,459 |631,024 |
| |Total cost |7,449,314 |2,172,047 |6,941,262 |
|Alternative 3 – Oxidation ditch |
|1 |Construction and equipment cost |5,089,463 |2,166,899 |6,742,340 |
|2 |Land acquisition and resettlement cost |1,834,357 |0 |0 |
|3 |Construction supervision cost |440,000 |200,000 |660,000 |
|4 |Contingency |736,382 |236,690 |740,234 |
| |Total cost |8,100,202 |2,603,589 |8,142,574 |
5 Accompanied facilities
1 Transmission pipeline to the treatment plant
A derivation runs into wastewater treatment plant /pipeline direction is expected from south-east of wastewater treatment plant to existing asphalted road nearby industrial zone with distance of 150m. As this line crosses existing drainage channel, which is being partitioned into many low impoundments for aquiculture ponds but not obstruct the flood water drainage. Therefore proposed road elevation for derivation which enters into the wastewater treatment plant is at +0.60m for the easy overflow through the low impoundments.
A derivation which enters into wastewater treatment plant is proposed in consideration of widening and lengthening planning the Dien Bien Phu Street towards the north of the city in the coming time. Upon the completion of widening and lengthening planning of Dien Bien Phu Street, it is required to consider the connection of wastewater treatment plant CEPT (and future wastewater treatment plant 1C) to Dien Bien Phu Street by short derivation with length of 100m. The elevation of this derivation will be subject to the elevation of Dien Bien Phu Street. And elevation +2.5m of finished level of wastewater treatment plant CEPT. The derivation enters into the second wastewater treatment plant will facilitate the access to the wastewater treatment plant in the future and supplement to dam for derivation and for protection corridor proposed in the existing project.
2 Effluent pipeline and Outlet Structures
Treated wastewater will be discharged into Ha Thanh River. Discharge points were proposed to be located in a distance of 1,200m to the Southeast corner of Wastewater Treatment Plant at site 2 as shown in Figure 1-5. Because the Ha Thanh River is shallow, river bed condition is soft soil containing silt/sludge. It is not feasible to construct an embed discharge pipe because the pile may have a high possibility to be blocked. It is difficult to maintain it in a long time. Therefore, discharge outlet structures were recommended to be designed in order to maximizely protect the wastewater transmission pipeline after treatment, and to facilitate for the stable and long time discharge of wastewater into the receiving bodies
Effluent is discharged into the river by gravity pipeline. The effluent pipe will be PVC pipe with DN of 630 and inner diameter of 600mm with PN6. Two DN 630 pipes will be installed in the same conduit for the safe discharge after treatment for both Phase 1 and Phase 2. The site plan is also estimated for the installation of 3rd pipe DN639 on the same line, in case wastewater treatment plant 1C next to wastewater treatment plant CEPT is constructed. The maximum safe elevation of output pipe from wastewater treatment plant without overflowing the SST overflow weir of sedimentation basin for phase 2 is +2.8m. Normal vibration amplitude of river water level daily at the discharge point is relative to high/low tide of +0.30m/-0.40m, so it will create propulsive force in the water head 2.5 and 3.2m. The water head can convey water wastewater discharge after treatment in the condition of maximum flow of phase 1 and phase 2 (2 x ADWF/mean flow in dry season) from wastewater treatment plant CEPT to discharge point into Ha Thanh river.
[pic]
Figure 1-6: Location of the main outlet
NATURAL, ENVIRONMENT, AND SOCIAL-ECONOMIC CONDITIONS IN THE PROJECT AREA
1 NATURAL ENVIRONMENT
1 Geographical Location, Topography and Geology
1 Geographical location
Qui Nhon City lies in the south pole of the Binh Dinh province. It is bordered in the north by Tuy Phuoc and Phu Cat district, in the south by Song Cau district of the Phu Yen province, in the east by the China Sea, in the west by Tuy Phuoc district.
More than 100 years ago, the City was born officially, however, City's forming and developing history goes with to 11th Century Champa culture, Tay Son dynasty and Thị Nại seaport from 18th century. In 1988, the primer Minister has decision No 558/QD-TTg, which recognized Quy Nhon as the second city and is one of three commercial and tourism centers of South Central part coastal (with Da Nang and Nha Trang). Quy Nhon City is economic, polictic, culture and science center of Binh Dinh Province.
2 Topography
Quy Nhon City area has a diversified terrain comprising mountains and hills, plains, paddy field, pond, lagoon, lakes, rivers, sea, peninsulas, and islands. Qui Nhon's coast- line is 42 km with a big lagoon area, brackish water lake and abudant sea creature resource and many of valuable specialties with high economic worth.
Quy Nhon City is divided into two areas including: (1) present Quy Nhon City and (2) Phuong Mai peninsula which has been expanded recently. The central area has the relatively flat terrain; altitude varies from 1,5m to 4m; slope direction from mountain to sea and from mountain towards basin of river; average slope from 0,5 to 1%; Average ground surface level in the centre of City varies from 3,5-5m, the area near River and Sea has is lower than 2m (as for the area of alluvial ground/aegiceras, vet trees of Ha Thanh river estuary is 0,0m), is usually flooded from 0,5 to 1m (p=10%).
Project area is located in Nhon Binh ward, in the north of Ha Thanh River. In general, terrain of project area is paddy field and aquaculture reservoir with high level low terrain, is far from land dam with low high level. Average space height may be -0.50 m concrete road directly leads to the north of plain which has average height is +1.00m. The road is asphalted by bitumen next to industrial zone, which is 150 m away from site 2 in the southeast having high level +1.50m..
3 Geology
Ha Thanh River side area and Thi Nai lagoon: layer 1 – grain sand mixing with shell with the depth of 1.2-5.4m; SPT mean value Ntb = 3; layer 2- clay sludge with variation depth from 2.0 to 18m; layer 3 – weak clay with variation thickness from 7.50-31.2m, Ntb=6; layer 4- semi-hard clay with variation thickness from 4.5-5m, Ntb=20; this layer is from el.-31m. At el.-36m, it is fine sand or clay stone.
In the project area, through out six boreholes at wastewater treatment plant site showing that there is a presence of sandy sludge layer of which its bearing capacity is poor right under the surface, this layer has a depth from 5-7m, next is soft clay layer 23-30m thickness, with high elasticity, and final is sandstone and stiff clay which is suitable for bearing piles.
Hydrogeology
Quy Nhon City lies in the North – East hydrogeology, in which water layer is the layer of paleozoic-mesozoic age and fractures in hard rock. Geology of Quy Nhon City most covers with sediment of Holocene age is ranked alluvium closed to river creating fine material grain (fine grain). In the south and west has high hills was made by metamorphic rock.
Because of fine grain of water layer material and locating near to sea so underground water reserves is not large. Underground water level fluctuated from 1,55m to 3,96m. The area of warp of Ha Thanh and Cong river (Tan An) have higher underground water potentiality usual supplying from water source of two rivers. The center of City has underground water level of 3-4m below the surface.
2 Meteorology- Hydrograph
1 Meteorology
Climate of Quy Nhon City is the same Binh Dinh province, bearing climate particularity of centre – central part affected by North-east monsoon in the rainy season and wester wind in the dry season. Dry season from January to August, the rainy season from September to December (rainfall in rainy season occupies 80% rainfall of whole year)
Some specific characteristic of Quy Nhon climate:
- Winter is not cold, populating Northwest wind to North Wind
- Summer has equal temperature; there are four months has average temperature over 280c. Wind way mainly has East and South East, predominating the half of summer is west and North West way.
- Rainy season in Quy Nhon area usually has storm, and big storm focused on October.
- Average annual temperature: 26,90C.
- Lowest average temperature: 26.90C.
- Absolute highest temperature: 39,90C.
- Annual average hot temperature: 30,80C.
- Absolute lowest temperature: 150C.
- Total sun hour of a year: 2521 hours.
- The relative highest humidity: 83 %.
- The lowest relative humidity: 35, 7%.
- The medium relative humidity: 78%.
(Sources: Adjustment of Quy Nhon City Master Plan, The characteristic of climate of Nghia Binh province, figure form Quy Nhon meteorology station).
The climate of Quy Nhon City is good in general, the rate of rainfall is not high, and the temperature of winter is not low but a considerable amount of sunny days. The climate as a whole is suitable for urban development. However, the long dry season may cause water resources exhausted, affecting the living and production. It should note that 80% rainfall lasts within three months per year, which can cause flooding in that duration. This will adversely affect the construction and recovery of drainage system.
A number of sunny hours
From March to December is much sunny period, 200-300 average sunny hours/month
From October to February in following year is less sunny period, 100-180 average sunny hours/ month.
Rainfall Regime
Rainfall in Quy Nhon allocates unequally in the months of year, focused on from September to December, occupying of 80 % rainfall of a year. Total average annual rainfall is 1.677mm; total average annual rainy day is 128 days. Months have the biggest rainfall in year is October and November; average rainfall is 300-500mm/ per month. In the months have lower rainfall is March and April; average rainfall is 15-35mm/per month.
Evaporation
From March to December is much sunny period, 200-300 average sunny hours/month
From October to February in following year is less sunny period, 100- 180 average sunny hours/ month.
Wind Regime
According to wind regime at the area shown in figure 2-1, the popular wind direction in winter months is north -west to north- east; from the following October to March, popular wind direction with frequency of 16-53%; north-east wind occupies 7-18%. At Quy Nhon station, from March to June, south-east wind appears with frequency of 15-27%. In June, July, August, west wind appears with frequency of 12-13%.
[pic]
Figure 2-1: Anemometric results at Quy Nhơn station
2 Hydrography
The centre of Quy Nhon City lies in in the south of Ha Thanh River which has 85 km length originated from an altitude of 1100 metres in the west of Van Canh district, flow southwest-notheast to Dieu Tri, divided into two branch: Ha Thanh and Truong Uc which flow into Thi Nai lagoon through Hung Thanh and Truong Uc estuary and then flow into Quy Nhon sea. The area of valley is 539 Km2; the total of river length is 58 km. the specfic form of Ha Thanh valley is presented on table 2-1.
Table 2-1: Characteristics of Hà Thanh River basin
| |Receivers |Distance to the river mouths |
| | |Traffic frequency (no/h) |Noise level (dB) |CO (mg/m3) |SO2 (mg/m3) |NO2 (mg/m3) |
|K1 |Crossroad of LHPhong and Tăng Bạt|400 |72.7 |10.305 |0.524 |0.564 |
| |Hổ | | | | | |
|K2 |Đống Đa Crossroad |500 |75.2 |8.015 |0.786 |0.376 |
|K3 |Nguyễn Thái Học – Tây Sơn |197 |69.9 |9.16 |0.786 |0.564 |
| |Crossroad | | | | | |
|K4 |Phú Tài Crossroad |143 |70.3 |6.87 |0.524 |0.188 |
|TCVN 5937:1995 | |70* |40 |0.5 |0.4 |
Source: Center of Natural Resources and Environment Technical Services, 06/2005
*: TCVN 5939:1995
3 Water environment status
1 Surface water
Quy Nhon Wastewater Treatment Plant project is located adjacent to the downstream of Ha Thanh River, is an important surface water natural resources for Quy Nhon City and the entire area under this river basin.
In the rainy season, water in Ha Thanh river is vitually fresh with salt content varies from 0.03% to 0.33%. However, in the dry season water is affected by a salty content of 10.4% penetrated deeply into upper reaches about 4.15 km. Salinity at the mouths of river at this time is about 31.6%. Some specific information about the water quality of Ha Thanh river is presented on Table 2-3.
Table 2-3: Water quality of Hà Thanh River at the proposed outlet of CEPT plant (12/2005-01/2006)
|Parameter |BOD5 |COD |DO |SS |NH3 |NO3- |
| |mg/l |mg/l |mg/l |mg/l |mg/l |mg/l |
|July to Aug |Oct to Nov |July to Aug |Oct to Nov |July to Aug|Oct to Nov |July to Aug |
Source: Department of Agriculture and Rural Development (2006). Project on Review of Irrigation planning
Table 2-4 shows that BOD5, DO and total coliform values in Thi Nai in August to November 2006 were above that of the limited value of standards TCVN 5943-1995. Domestic wastewater from the urban areas discharging directly into the lagoon through some outlets may be the main reason of this excess. The data of Thi Nai lagoon water quality in dry season was not available. In the dry season, water quality of the lagoon may be worse than that in July to November.
2 Groundwater
In general, underground water resource in Quy Nhon City is very poor. In some areas of the city, underground water is used as the main supply water resources but low poor quality. At 9 group of Dong Da ward, almost underground water is affected by salinity. There are many wells with the depth varies from 3 to 5 m for brackish water which are only used washing (impossible for eating and drinking).
Following the report, at medical station of ward there is a digged well with very good quality water, which is being exploited with a capacity of 300m3/ per day for approximately 10.000 residents in Group 9, Đong Đa ward. At Luong Nong, Nhon Binh ward, underground water is rather plentiful but high salinity intrusion affected. On the other hand, at Tan Dinh area, quality of underground water is better and can be used for eating and drinking.
According to a report of Binh Dinh Department of Natural Resources and Environment (DoNRE) in 2005, underground water of Quy Nhon City was polluted. At some underground water quality monitoring locations, pH indicator is lower than standard, COD content is quite high (at residential area surrounding Bau Sen Lake, measured COD is 16.7mg/l). Simultaneously, underground water is also infected by bacterium with a quite high content (in the area along Tran Quang Dieu street, coliform indicator is 240 MPN/100ml).
4 Biodiversity
1 Agricultural ecology at the project site
Although Nhon Binh ward belongs to Quy Nhon City but now this area is considered as a rural area and agriculture area. Most of this area is rice-cultivated land and shrimp and fish hatching lake. Ecosystem is rather monotonous with numbers of residential house is rather scattered, paddy fields and some swamps were improved for aquaculture. At project area and surrounding areas there is very few wild residence places, except for only some fallow swamp area. In here, there is no presence of valuable and rare animal species or threatened animal species. The structure of animal is quite simple, including domestic animals and shrimp and fish hatching species. Structure of flora is very poor with some trees, around the local houses and some aquatic flora growing in salt sulphate soil.
|[pic] |[pic] |
|Figure 2-2: The representative land form at the area location |Figure 2-3: The artifical lakes to raise seafood (core zone of |
|(core zone of Phase1) |Phase 1) |
2 Thi Nai Lagoon
Thi Nai Lagoon is considered as the final water catchment to receive treated water from the concentrated wastewater treatment plant. This lagoon is always full of water and has a rich biodiversity, which can be influenced by the operation and maintenance of the wastewater treatment plant. The convention of United Nations on wetland (Ramsar Convention), defines wetland is “Wetlands are areas of marsh, fen, peatland or water, whether natural orartificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters".
Among important wetlands including tidal-submerged land, swamps, internal flooded grassland or flooded forest and peat swamp, mangrove forest, coastal lake and lagoon, flooding plain, delta, and estuary, Thi Nai Lagoon is considered as an important wetland in terms of biodiversity.
The World Conservation Monitoring Centre (WCMC) includes the Quy Nhon Swamp on its list of sensitive wetland areas in Vietnam. This natural saline swamp is a part of the Thi Nai lagoon complex located on the coast north of Quy Nhon City, Binh Dinh Province. The swamp has an area 5,000 ha at high tide; 3,200 ha at low tide, with a 700 m wide channel that opens to the sea. Several rivers, including the Ha Thanh, Con Rivers, flow into the swamp, the average depth of which is 1 - 2 m and the maximum depth is 7 – 10 m.
There are several small islands with mangrove forest in the northern part of the lagoon. One hundred and thirty-six species of flowering plants and algae have been recorded at the swamp, along with numerous species of phytoplankton including 50 species of Rhodophyta (red algae). The red algae Gracilaria verrucosa is particularly abundant is widely cultivated in the swamp for dried use and export as an emulsifier (agar). Shrimps are also widely cultivated in this swamp which may be influenced by discharges into the Thi Nai Lagoon.
Due to the effect of urbanization and the economic development of the area, at present only the north area of the lagoon still maintains the original ecosystem whereas in the south area (near entrance of Quy Nhon bay) has greatly changed, especially during the construction duration of Nhon Hoi bridge. The mangrove forest in the mouth of Ha Thanh River has been lost partially.
2 SOCIO-ECONOMIC CONDITION AT THE PROJECT AREA
1 Overview of Socio-Economic Status at Project Area
According to the figure of the statistical yearbook of Quy Nhon City, the population of the city is around 264,800 people with rate of natural growth is 1,13%, in which urban area has 236,400 people (occupying 89%). The average scale of a household is five persons. The economics of Quy Nhon City has developed dramatically, which results in the improvement in the daily life of residents. The economic mechanism has changed according to tendency to increase the ratio of construction, industry, service branch and to reduce the ratio of agriculture and forestry branch.
Gross Domestic Product (GDP) in 2006 reached 12,314.529 billion VND (real price), increased by 19,60% compared with 2005, in which production value of industry and construction is 3,479.015 billion (occupying 28.2%), agriculture and forestry and aquatic product get 4,505.139 billion VND, occupying of 36.6% of GDP. In Quy Nhon City, there are much more 2.231 small and large industrial businesses and 11.593 service business, which create job for 73.800 worker. Not including thousands of individual businesses. Branches, fields has greatly contributed for state budget is processing industry, tourism, mining industry. In which tourism branch has greatly contributed and much more increased in the GDP mechanism of City.
1 Residence Status and Income of Household
Household Scale
Totally, 97 affected households were interviewed. A total of 423 residents were affected of which 206 male and 217 female. Average population of household is 4.4 persons, fluctuating from 1 to 10 persons per household. Population in the working age of each household is 2.3, the highest is 6 persons per household. There were 7 households did not have any person in the working age and these households had the income from farming or supports from their relatives.
Household Income – Job Mechanism
In the total number of interviewed households, there are 16 poor households (poor household has average income less than 260.000 vnd/month/ per person, It is caculated under urban standard.). In which there are 7 households have key income from cultivating paddy. A number of households have income from 260.000-600.000 vnd/month/person, occupying a high rate compared with 64 households. 17 Remaining households have income from 600.000 vnd/month/person and over. The income of households in project area is relative low compared with households lived in Quy Nhon City.
Almost households cultivating wetrice (occupying 76,3%). However, there are 16 households (16,5%), of which consider that it is themain income and it will affected largely if the cultivated land is acquired. Paddy fields can be cultivated from 1-2 season per year depending on anual natural water resources.
The income of 48 households (49.5%) is from employment services. Income of 14 households comes from working for factories, shops such as wood shops in Quy Nhon city with mean income of about 50,000VND/day. Economic effects by removing or land acquisition on these households is not much as their major income is not subject to farm land. However, 78 households (80.4%) of interviewed households have income from other auxiliary services.
Table 2-4: Source of revenue
| |Agriculture |Hired labour |Worker |Others |Total |
|Number of households |16 |48 |14 |19 |97 |
|Percentage (%) |16.5 |49.5 |14.4 |19.6 |100 |
About living condition, all interviewed households are using the national grid. In area, there are primary school, post-office, medical station. However, there are about 50% households which use potable water, remaining households do not have potable water due to they do not approach the water supply system.
Education Level
Education level of household owner mainly is in primary and junior high school with correlative ratio is 41.2 and 40.2%. In general, old people in this area have an education of primary school level. There are three illiterate people, who are old people. Whereas young people have junior high school level. In a number of 423 people, 101 people are still going to school.
Table 2-5: Types of qualification gained by the heads of the household
| |Don’t know how to read and |Elementary school |Secondary school |High school |College/university |
| |write | | | | |
|No. |4 |40 |39 |10 |4 |
|Percentage (%) |4,1 |41,2 |40,2 |10,3 |4,1 |
2 Accommodation status
Right of agricultural land use was granted for people in 1997 by the People’s Committee. At that time, a person was granted for 500m2 to farm. In the socio-economic survey, the area of person is 470 m2. Right of land use was granted by province up to 2017. In a number survey households, there are 19 households do not have land, in which 10 households have income from wages. In general, each household has house area about 50-150 m2 in total area is 100-500m2. In buffer zone of project, there is a temple with local range, which is usually offered sacrifices in the full -moon day and festivals by local residents.
2 Status of water supply and sewerage
1 Status of water supply
The present water supply system of Quy Nhon was formed since the former regime in a small scale. The system was then improved, upgraded and developed into a more perfect water supply and sewerages system, including drilling wells for water exploitation, sterilization system and drinking water distribution network to consumers. The current capacity of water supply system is 20,000m3/per day which is mainly distributed to wards within city and some outskirts under urbanisation process. Water resources were mainly exploited from Ha Thanh well area in a distance of 9 km from the center of City.
Water pumped from well will be transmitted by pipeline (600, (500, (400 going along highway 19 Quy Nhon-Song Cau to Quy Nhon City. The entire city has an approximately 120.000m with diameter is from (400 ( (500 pipe, almost is old pipes. Presently, the city has executed the water supply project funded by ABD, loan No. ADB 2146-VIE. Scope of Project related to water supply system, including the improvement of well pumping station, catch basin, pumping station II, existing pipelines in order to reach a capacity of Q=20,000m3/per day. Simultaneously, building 9 well pumping stations near the River Con 25 km from the city to convey the water to new constructed Dieu Tri Water Treatment Plant with capacity of Q=25,000m3/per day. With this project, average water supply standard from 50 litres/per person/ day, basically meeting resident’s water demand of Quy Nhon City.
According to the statistics, as of June 2003 there have been 25.762 connecting points to water supply networks of the city. As estimated, it is possible to supply to 52% domestic water demand and the number of persons at one connecting point is 5.6 persons/water meter. It is expected by Water Supply & Sewerage Company, in years of 2010, 40,000 households will connect to water supply networks. This is the result from the project financed by ADB. This water supply system will be constructed by local fund.
2 Existing drainage and wastewater treatment status
Overall water drainage network of the city
Water drainage network of Quy Nhon city is the sewerage system used for rain water and wastewater drainage jointly. In fact it is gravity drainage for rain water jointly with wastewater from sources in the city.
Overall water drainage network, the city may be divided into 3 areas.
- The center of the city
- The west area of the city (Bui Thi Xuan, Tran Quang Dieu wards)
- Phuong Mai peninsula area
Water Drainage Organization
The city comprises the receiving bodies as follows:
- Ha Thanh River
- Thị Nại Lagoon
- Dong Da Lake
- Phu Hoà Lake
- Quy Nhon Bay
Because of the completely gravity drainage systems do not have suitable oulet structure, effectiveness of drainage system in some hollow areas of centre of city relies upon tidal regime.
Water drainage network
Water drainage network of Quy Nhon city (under the control of Urban Environment Company in 2004) includes 87,552 m drains and 2,648 valve chambers. In addition to there are many open drainage ditches.
Water drainage network of center area of previous city may be divided into 3 main valleys; water is drained to 3 various directions:
- The valleys draining to Ha Thanh river mouth and Thi Nai dam (north direction of the city)
- The valleys draining to Quy Nhon Bay towards east direction of the city (from the north to the south) .
- The valleys draining to Phu Hoa lake locating in the west of the city.
Regulation Lake System
In the city, there are natural lakes such as Bau Sen, Dong Da, Bau Lac, Phu Hoa (Son pass), which regulate the rain water and wastewater. Bong Bong lake also regulates the rain water and wastewater and land scrapping for the city. The lakes with crowded inhabitants living nearby are often polluted by domestic wastes such as Bau Sen lake or Dong Da lake. Other lakes have not been polluted yet or pollution level is still low.
Discharge Outlet, Tidal Gate
According to the statistics in 2004, the drainage system in the city centre comprises 13 discharge outlets of difference, excluding discharge outlets were buried during construction. These discharge outlets without tidal gate.
Sewage Collection and Treatment
Domestic wastewater is collected into common water drainage network of the city through connection pipe from households to public drainage network The number of connection points from households to the city’s water drainage network has been carried out by VIWASE in the so-economic survey in project area. The result shows that about 93.9 % of households use toilets with septic tanks and semi-septic tanks and 3.9% of households use the toilet with sink. The ratio of toilet using water is very high, however 34.2% of households connect to water drainage network; 52% of households let the water to be absorbed into the ground and 5.9% of households discharge directly the wastewater into pond and lake.
A common way of the coastal people in the Middle and Southern Middle of Viet Nam is to discharge the waste water directly to the ground instead of using the drainage pipeline because the soil ground of these areas is soft, mixing with sand and high absorbability. In urban areas with high density of construction and population, volume of waste water is very big; the solution of absorbability causes the risk of environment pollution, especially It directly affects the underground water and soil environment. In many urban areas such as Quy Nhon, Nha Trang, Phan Thiet and Vung Tau, etc., the underground water has been polluted by the waste water intrusion.
The domestic waste water from households whose pipelines connect to the water drainage network is not separated, collected and treated but it is discharged directly to the catching sources. The waste water together with the rain water is discharged directly to the natural environment (e.g. seas, rivers, pond and lake). At present, in Quy Nhon city still has no had domestic wastewater treatment plants yet.
Collection and treatment of public waste water
In principle, waste water from all public utilities (e.g. hospitals, schools, entertainment areas, etc.,) has to be treated separately before it is collected into the drainage network. However, in fact, most of the public utilities have no waste water treated system or some have but work ineffectively. According to statistics, Quy Nhon city has seven big hospitals, of which four hospitals have the waste water treated system (capacity from 80 to 300 m3/day) before discharging to the drainage network. Now, there is have no specific survey about the status and operation of these waste water treated systems. However, most of them operate perfunctorily and ineffectively.
Management and operation of the drainage system.
Water drainage network in Quy Nhon city is managed, operated, repaired and maintained by Quy Nhon Urban and Environment Company (URENCo). The cost for construction and operation of drainage network is limited, it is mainly used for repair, maintenance and improvement of existing system. Just few drainage pipelines are new built or replaced . For taking back a part of cost, according to the Vietnamese regulations, URENCO collects the charges from 3,030 households in the center city which occupies 6%. The Company signed the contracts with the households whose have the demand to connect their pipelines to the public drainage network and running into septic tank. The collected data in the city shows the rate of the streets which have drains is very high; it is about 0.88 km of drains/km of street.
Conclusion
However, capacity of water drainage network is still limited, it does not meet the demand of drainage in the city. Based on the results of actual survey during the implementation of the project and based on the evaluation of Management Unit (URENCo), the quality of drainage pipelines constructed before year of 1975 has been downgraded considerably, even some sections were damaged. The construction of sewerage systems for waste water and rain water by URENCo will improve this condition in future.
3 Collection of solid waste and septage
In the last years, there was not specified data statistic about volume of solid. The quantity of solid of each type is shown in Table 2-6.
Table 2-6: Total volume of solid waste in Quy Nhơn City (2004)
| |Type |Emission rate |Total |Collection rate (%) |
| | |(kg/capita.day) |(tons/day) | |
| |Urban domestic solid waste |0.8 - 0.9 |320 |50-60 |
| |Rural domestic solid waste |0.2 - 0.3 |250 | |
| |Industrial solid waste |0.1 - 0.2 |250 |60-70 |
| |Clinical solid waste |0.8 - 1.0 (kg/bed.day) |0.2 |70-75 |
| |Total | |820.2 | |
Source: DONRE, 2005
At present, sorting of solid at the source has not carried out. All types of wastes from households, companies, schools, markets, etc., are collected together and transported to waste stockyard. In Quy Nhon city, the rate of waste collection is relatively high in comparing with the general status; it is about 75% to 85%. However in Binh Dinh province, there have been no wastewater treatment plants.
4 Status of flooding
Partial inundation occurs often in rainy season (from September to November) with the maximum flow due to the water from the mountains running into the city. Studying the tide level in Quy Nhon from recent years shows the fluctuation of tide level is not high, only between 1.0m and 1.5m. In months of inundation, the quantity of rain is high, the variation of minimum tide level from 0.3m to 0.7m. Generally, the impact of tide on the drainage network is not much due to the tide is only approximately 1.0m whereas the topography in the city is 2.0m high and over except for the northern area of the central city. Inundation not only occurs in inhabitant areas with the low elevation and low drainage possibility but also in some main streets in central city.
Based on the Feasibility Study by Hydrographic Studying Center – Hydrometeorology Institute: “Survey and evaluation of the impact of water flow, drainage inundation in north side of Ha Thanh River, Nhon Binh ward, Quy Nhon city, Binh Dinh province”, Location of CEPT Waste Water Treatment Plant in the north side of Ha Thanh River, Nhon Binh ward is affected by inundation. The area in Nhon Binh ward was inundated from 1.6m to 1.8m by the inundation in 1999. This Feasibility Study also shows two calculated results for safety elevation of bedding elevation against the inundation with the designed frequency of 100 years and 20 years (P = 1% and P = 5%). Plant is located in area with designed elevation of bedding elevation of 3.08m and 2.41m respectively (the same of Mui Nai elevation system).
5 Power Supply and Lighting Status
The City uses electricity source of 110 KV national networks through 110 KV two transformer stations are Phu Tai station and Quy Nhon station. Phu Tai station has three lines 110KV connected with Vinh Son hydroelectric plant, 110 Quy Nhon Station and one line go to Phu Yen. For 35KV grid, apart from one transformer station at Quy Nhon station, there are still other two transformer stations at Phú Tai, taking electricity from 110KV and Nhon Trach stations. Except a few of enterprises in Phu Tài area, taking electricity from 35KV grid, almost additional charge is taken from 22KV grid. City has about 200 km lines of grid.
6 Master plan of Water Supply for Quy Nhon City (until 2020)
Using the underground water from wells at Ha Thanh River (capacity of 20,000 m3/day), Tân An wells at Con River (capacity of 25,000 m3/day), wells in The Thanh (capacity of 8,500 m3/day) and the upper water of Dinh Binh Lake–Con river (capacity of 96,500 m3/day), expected area for taking water in Dap Da town – Nhon An town. Standard of water supply is shown in Table 2-7.
Table 2-7: The standard of water supply for Quy Nhơn City by 2020
| |Unit |Value |
|For domestic uses | | |
|Initial phase (by 2010) |l/capita.day |110 |
|Long-term (2010 – 2020) |l/capita.day |150 |
|Industrial uses |m3/ha.day |40 |
|Tourism uses |l/capita.day |300 |
Source: DONRE, 2005
Table 2-8 shows the demand of water in the whole Quy Nhon city. Demand of water until year 2010 is 63,420 m3/day and year 2020 is 155,340 m3/day.
Table 2-8: Water demand for Quy Nhơn City
| | |Standards of water supply |Total (m3/day) |
| | |2010 |2020 |2010 |2020 |
|Domestic uses |Q1 |110 (l/capita.day) |150 (l/capita.day) |30,000 |70,000 |
| | |x population |x population | | |
|Public services |Q2 |10% Q1 |20% Q1 |3,000 |14,000 |
|Street cleaning and tree |Q3 |8% Q1 |10% Q1 |2,500 |7,000 |
|watering | | | | | |
|Tourism uses |Q4 |300 (l/tourist.day) |300 (l/tourist.day) |720 |840 |
|Industrial uses |Q5 |40 (m3/ha.day) |40 (m3/ha.day) |10,700 |26,300 |
|Loss |Q6 |30% Q1-5 |25% Q1-5 |13,500 |30,000 |
|Internal uses in WSTP |Q7 |5% Q1-6 |5%Q1-6 |3,000 |7,200 |
|Total |Qtc | |63,420 |155,340 |
Source: DONRE, 2005
ENVIRONMENT IMPACT ASSESSMENT OF THE PROJECT
1 ENVIRONMENTAL IMPACT ASSESSMENT IN CASE OF WITHOUT PROJECT
Prior to yhe construction of the CEPT plant, the CCESP has designed that the wastewater collected by the sewerage would be discharged to the Hà Thanh river through three temporary outlets which are shown in Figure 3-1. This temporary discharge could increase the pollution loading in the receiving water. In order to simplify the calculation, these following assumptions are proposed:
- Concentrations of BOD5 and COD remain unchanged and homogeneous
- Flow-rate of wastewater and receiving waters are constant
- Mixing between wastewater and receivers are complete at the outlets.
[pic]
Figure 3-1: The location of the temporary outlets of CCESP
In order to assess the impacts of discharging wastewater to the Hà Thanh river, the QUAL2K model is applied to simulate the possible scenarios that could be happened in reality. The pollution transmission is calculated with the assumption that all of the untreated wastewater will be directly discharged into Hà Thanh river. However, the report also takes account of the worst case of highest loading of pollution when all of the wastewater in the Phase 2 (2023) is discharge without treatment.
1 Phase 1: Q = 7000 m3/day
In the flood-tide regime, the highest value of BOD concentration at the outlet is 5,5 mg/L which is much smaller than the required value in TCVN 5942:1995 (B column). That means Hà Thanh river has a capacity to accept all of the untreated wastewater. The pollutions will be transmitted and BOD concentration will decrease along the river with regards to dilution and biochemical oxidation. The DO concentration decreases and reaches the lowest point at 3.9 mg/l at the distance of 5.5 km from the outlet. However, the concentration of Coliform at the outlet is 4.2x105 MPN/100 ml which is greatly higher than determined in the TCVN 5942-1995 (column B, 104 MPN/100 ml). Therefore, the disinfection of wastewater prior to discharge into receiving water is extremely necessary.
In the ebb-tide regime, the highest BOD concentration at the outlet is 19.4 mg/l which is still in the allowed range of TCVN 5942:1995 (column B). The DO concentration reaches the lowest level of 2.7 mg/l at the 2km downstream from the outlet. Similar to the case of high-tide regime, the concentration of Coliform is higher than the permitted value.
2 Phase 2: Q = 28,000 m3/day
In the flood-tide regime, the highest value of BOD concentration at the outlet is 14.56 mg/L which is still acceptable. The pollutions will be transported into Thi Nai lagoon and BOD concentration will decrease along the river. However, the DO concentration decreases below the permitted value from 4.5km to 11.5km downstream from the outlet. However, the concentration of Coliform at the outlet is 1.6x106 MPN/100 ml. In the ebb-tide regime, the highest BOD concentration at the outlet is 66.1 mg/l which is excess the allowed value of TCVN 5942:1995 (column B). In this case, Ha Thanh river could not receive all of the wastewater loading. As a result, it is necessary to consider the solution of applying partial treatment. In the distance from 1.0 km to 4.0 km downstream, the DO concentration is nearly zero. The concentration of Coliform is 8.6x106 MPN/100ml which is higher than the permitted value.
2 OVERVIEW OF THE IMPACTS BY THE CEPT WASTEWATER TREATMENT PLANT
Judgment and impact evaluation includes the direct positive and adverse impacts and indirect impacts of the proposed project. Impacts to the possible events shall be evaluated first; secondly, the importance role and effects of these impacts; thirdly, consideration of possibility to minimize the adverse impacts
[pic]
Figure 3-2: Diagram of construction of CEPT plant and its environmental impacts
Figure 3-2 generalizes the environment impacts in pre-construction and construction stage. In the operation stage of CEPT Waste Water Treatment Plant, due to methods applicable for treatment with different technologies, environment impacts shall be evaluated separately. Environment impacts of the project in the operation stage is evaluated in detail by three alternatives and shown in figure 3-3, 3-4 and 3-5.
[pic]
Figure 3-3: Environmental impacts of alternative 1
[pic]
Figure 3-4: Environmental impacts of alternative 2
[pic]
Figure 3-5: Environmental impacts of alternative 3
3 IMPACTS IN THE PRE-CONSTRUCTION PHASE
In the design stage, some works such as investigation, site survey, collection of inhabitants’ ideas, etc., for preparation of the feasible study also causes effects on inhabitants’ living due to land acquisition and compensation. This impact, however, is not very significant.
The project site is located in Nhon Binh ward, it is estimated to land acquisition of about 91 hectares for the plant construction, in which permanent acquisition is 12 hectares, it is mainly the ponds for growing shrimps; acquisition land for buffer areas surrounding the plant is 79.2 hectares, mainly rice fields and some parts of tenure land; and temporary acquisition land for construction of conduits after treatment. Table 1-7 shows in detail the scope of land requirements for three alternatives. The facultative pond alternative requires the largest area.
A detailed survey was done from September 2nd, 2007 to September 9th, 2007 to assess the components of the project area which was assumed to be required in trickling filter alternative or oxidation ditch alternative. The survey for the facultative lagoon alternative has not been defined yet.
Table 3-1: Land demand for the CEPT plant
|Area |Type of land |Area (m2) |
|Core zone |Living purposes |785 |
| |Gardening purposes |81 |
| |Agricultural purposes |15,737 |
| |Aquacultural purposes |102,997 |
| Total (1) |119,600 |
|Buffer Zone |Living purposes |17,345 |
| |Gardening purposes |21,930 |
| |Agricultural purposes |751,426 |
| |Aquacultural purposes |1,300 |
| Total (2) |792,000 |
|Total (1) + (2) |911,600 |
The project will effect about 97 households located in buffer areas of the project. Based on the community consulting opinions made on September 02nd, 2007, many households have no opinions about land acquisition and compensation since they have no information of the project. 65 households (68%) have no information of the project, 26 households (26.8%) heard verbal information, 65 households have no opinions of plant construction, 29 households (29.9%) agree with plant construction and 3 households do not agree with this issue. The concern of project affected households due to the construction of the project, 22 households have no ideas. Most of the other household’s concern are about removing and acquisition of their cultivated land (41 households, occupies 42.3%), 47 households, (48.6%) concern about unfair compensation for settlement.
Table 3-2: Summary of affected households in site clearance
|Type of affection |Number |
|Number of households affected |97 |
|Number of households wanting to live in the resettlement area |91 |
|Number of households wanting to move themselves |6 |
|Number of households having their business affected |3 |
|Number of households losing more than 20% of their agricultural land |65 |
|Number of poor households |16 |
|Number of households having disable or died veterans |14 |
In case of removing, the people have two options for their removing namely: concentrated resettlement or separate resettlement as required by project affected people. The survey result shows 14 households (14.4%) have no ideas about resettlement. 77 households (79.4%) want the concentrated resettlement. According to their opinion, it is very difficult to purchase a new land with market price. Six households want to be compensated by cash and they will arrange a new location by themselves.
One of the characters of the farmer in this area is that their house is very near or next to the cultivated land. This is easy for them to take care their garden. 25 households (42.4%) of 59 households affected by the project have no ideas about agricultural land to be acquired by the project. 14 households (23.7%) want to receive cash for the land acquisition and 20 households (33.9%) want to receive cash for interval cultivate during project construction period and continue to cultivate on their land. However, the construction of the project will affect on their irrigation channel and rice fields and they also encounter the difficulties in taking care of their garden when living away from the cultivate land.
4 IMPACTS IN THE CONSTRUCTION PHASE
The construction of wastewater treatment plant and drainage system after treatment will both protect human’s health, and water quality in rivers and arroyos. However, if the planning, technical design, and technology application are not properly utilized, together with unsuitable equipments, it will not give effectiveness but also causing long term and short term adverse impacts, affecting natural resources and environment. Potential impacts during construction stage including mainly activities carried out during worker mobilization, materials, grading period and haulage of materials and sludge.
Table 3-3: Potential impacts in the construction phase
|Main activities |Sources of potential impacts |Representative impacts |
|Worker gathering |Daily activities of workers |Generation of domestic waste of worker |
| | |Increase in traffic density |
| | |Influence on local safety and social issues |
|Construction material |Activities of transportation means |Noise, dust, air emission from transportation means |
|gathering | |Traffic accidents |
| | |Increased traffic density |
|Site clearance |Activities of transportation means |Noise, dust, air emission from transportation means |
| |and construction equipments |Potential accidents |
| | |Damage the local ecology |
|Dredging and transferring |Activities of dredging equipments |Water pollution |
|sludge | |Noise, dust, air emission from transportation means |
| | |Potential accidents |
| | |Damage the local ecology |
1 Impacts on the air environment
1 Air pollution
Air and dust pollution will be generated within the construction area from construction vehicles and machines operation during construction and excavation process and activities during construction of CEPT Wastewater Treatment Plant including:
- Dredged mud from the ponds
- Site grading and levelling
- Construction of transmission pipeline after treatment
The dredged mud is mainly un-contaminated. Therefore the priority option for mud disposing is re-used for back-filling. In the case that there is no demand for backfilling, it will be disposed to the Long My landfill. This report will assess the worst case when the longest route is taken into account. The estimation of dredged mud and excavated soil are presented in detail in the Annex. Table 3-4 presents the estimated concentrations of pollutants.
Table 3-4: Emission loading of air contaminants in the construction phase
|Source |Emission factor |Loading (kg) |
| | |Alt1 |Alt2 |Alt3 |
|Loading of dredged mud | | |210,000m3 |210,000 m3 |210,000 m3 |
|Total of soil for plan leveling | | |150,000 m3 |242,500 m3 |263,600 m3 |
|Number of trips per day* | | |46 |57 |59 |
|Dust emitted from site clearance | |1 – 100 g/m3 |150-15,000 kg |242,5-24,250 kg |263,6-26,360 kg |
|Dust emitted from transportation | |0,1 - 1 g/m3 |15-150 kg |24,2-242,5 kg |26,3-263,6 kg |
|activities | | | | | |
|Smoke emitted from transportation |Dust: |4.3 kg/ tons DO |270 kg |380 kg |390 kg |
|means and construction equipments |SO2: |0.1 kg/ tons DO |6.5 kg |9 kg |9 kg |
|which includes dust (excluding dust |NOx: |55 kg/ tons DO |3500 kg |4870 kg |5000 kg |
|emitted from transportation), CO, |CO: |28 kg/ tons DO |1800 kg |2480 kg |2550 kg |
|hydrocacbon, SOx, NOx. It is assumed|VOC: |12 kg/ tons DO |800 kg |1062 kg |1090 kg |
|that trucks with capacity of 3,5-16 | | | | | |
|tons are mainly used. DO (S1%) is | | | | | |
|the main fuel. | | | | | |
Note: Emission factors are taken from WHO, 1993.
*: It is assumed that the total duration for construction is 2 years.
Dust can impact upon health of human via some diseases such as blepharitis, angina, asthma, bronchitis. In the urban environment, dust may be the agent conveying poisonous polluted substances such as lead, cadmium, aromatic compounds. Besides, Air substances such as CO, THC, and NOx can cause impacts upon nervous system and blood circulation impact. NO2 can influence on respiration at concentration 5ppm after some minute contact.
2 Noise pollution
The noisy caused by construction work is mainly generated by trucks used for transporting materials to the site of the project and carry disposal from the site and from other construction plants. The forecasted noise at the distance of 1m from the generating source is shown in the Table 3-10.
During the construction, noisy source will be about 10-20m far away from inhabitant area. According to available survey data, existing noisy level from vehicles along the streets in the city is about 65-75 dBA, in comparison with basic conditions, the noisy level which is sent from vehicles and construction plant is higher than the existing noisy. However, forecasted noisy level at the distance of 10-20m from the generating source will be reduced. In some cases, noisy level at the distance of 10m from the generating source is higher than national standard. This will be included in the Annex I.
2 Impacts on the water environment
Construction period will, during a short time, cause impacts upon water environment:
- Reduce ambient water quality of the receiving bodies near to the works due to execution activities.
- Reduce the quality of underground water due to execution process.
The environment pollution at the site is caused by sludge sedimentation and debris. Surface water source will be seriously affected by overflow rain water, water to be discharged from the works and domestic wastewater by the workers.
Firstly, with the number of workers working on the construction site brings about the construction of camps, temporary houses for working as well as resting. Worker’s daily activities on the construction site produce wastes which may cause partial pollution for water environment. The pollution level and impact on water environment is substantial subject to the number of the site workers and the way to control domestic wastes to be proposed in this project. Total volume of waste water from temporary houses of the workers is estimated about 5m3/day (with estimated number of workers of 100 persons and 501/person/day). Although the waste water volume is not big, it contains high BOD, SS content and diseases. To ensure hygiene condition, collection and treatment of wastewater which is undertaken by the contractor shall be specified by the project owner. Similar with many other projects, these impacts is not considerable and it can be minimized by septic tanks.
Polluted rain water overflows through construction site due to excavation and installation of pipelines. Overflow wastewater contains high content of suspended solid agents because it has gone with sand and clay. Water flow is subject to area, rain water volume and construction site is not covered with roof. The stock of soil for filling and material and construction plant also cause pollution possibility and impacts on water environment.
Overflow water from spray vehicles and water in the pits contains suspended solids, oil. The volume of water is subject to the number of vehicles access to the site. The water volume is discharged from spray vehicles is about 20-40 litters.
In summary, In spite of adverse impacts on water environment during the construction of infrastructure of industrial zones as above – mentioned, it is just temporary adverse impacts during the construction of the project; it is not permanent and consecutive throughout the process of the project.
3 Impacts of solid waste
Domestic waste generated from construction workers can be calculated based on the maximum numbers of working labor during construction period (it is estimated about 100 people). Estimated solid waste is approximately 50kg/day based on 0.5 kg/person/day and assuming that the workers are allowed to have meals at the site. This waste quantity is insignificant and will be collected and treated by the collection contractors.
During construction, grease and oil residuals may be generated from maintaining and preparing vehicle and machinery. According to technical documents, the average oil residual from construction machinery is around 7 liters per change of oil and the period of changing is every 3 - 6 months. If the estimated number of construction vehicles and related machinery is 30 units, the oil residuals that would be generated are around 30 - 70 liters / month. Such residual grease and oil are listed as hazardous wastes (code: A3020, Basel: Y8). If strict management measures for collection and disposal of residual oils are not applied, it can be a potential source for soil and ground water pollution at the construction site. Chemical waste comprises paint, detergent, oil used for machinery maintenance. However, these wastes are generated only if poor management condition and use. Construction waste mainly is spoil, which will be re-used for grading, thus it will not impact significantly.
4 Other impacts
Similar to any scale construction site, safety action is the most important issue needs special attention by contractors and labour working directly at site. Potential possibility that may cause accidents includes as follows:
- During construction of the drainage and sewage culvert systems, it needs to pay special attention to prevent the possibility of pollution to drinking water resources.
- Construction site shall have several haulage vehicles moving in and out, which may lead to the accidents caused by these vehicles themselves;
- Not properly perform the regulations on working safety to cranes, uploading equipment, construction materials which are highly heaped up and can be felt down, etc.;
- Working in the high-rise structures will increase possibility of causing accident to the labor by slipping from the scaffolds, buildings under construction, hoisting of construction materials (cement, sand, steel, etc.) and many other causes;
- Accidents at work from activities which contact closely with electricity such as construction of power system, hitting against the electricity lines crossing the road, storm wind breaks the electricity lines, etc.;
- During clearance at the wind land areas, the labor is likely to be attacked and beat by the reptiles such as snake, scorpion, ant, insect, etc., and there are possibilities causing the danger to the life of the beaten people;
- In process of construction as well as site cleaning, if the workers carry out the work carelessly (smoking, firing, cooking, etc.), then possibility to cause the fire is practical, especially during windy days, fire can be spread quite quickly on the dry land area;
- Fuel sources (FO, DO oils) which are normally contained on the jobsite area, is a serious explosive resource. Especially, when stockyards, storage areas are located near heat strengthening places or where gathered by many people and moving vehicles;
- The other explosive problems can be generated from electricity.
5 IMPACTS IN THE OPERATION PHASE
Impacts in the operation phase of the wastewater treatment plant are accessed in two stages: start-up and operation.
- The start-up stage: The duration for starting-up which is necessary for micro-organism to acclimate with wastewater to achieve a stable growth is different form one alternative to another. The alternative 1 (facultative ponds) does not require starting-up due to long retention time. The alternative 3 (oxidation ditch) requires about 2 weeks (with acclimated sludge from other wastewater treatment plants) or 1 month (with “new” sludge). The longest starting-up duration is of the alternative 2 (trickling filter). 2 months are required for micro-organisms create the biofilm. In the start-up, the performance of biological treatment facilities are very low, about 20-30% of fully operation.
- The operation stage: in this stage, the performance of each facility is stable. Each treatment facility has its own impacts which are assessed in detail in the following sections. In the operation phase, the incidents are predicted and assessed too.
1 Start-up stage
The preliminary and primary treatments do not require start-up as in the biological treatment. How long the starting-up phase lasts depends on the selected biological process, activity of cultivated sludge and the mass of cultivated micro-organism.
In the starting-up stage, the concentration of BOD, Coliform, SS, total nitrogen and total phosphorus are high because the performance of biological treatment is low. Therefore, this temporary discharge can result in the impacts presented in table 3-5.
Table 3-5: The impacts of untreated water onto receiving water bodies
|Parameters |Effects on the environment |
|COD, BOD |Cause DO depletion in the receiving water bodies ( influence on aquatic ecology. In the worst case when septic |
| |condition is satisfied, it could cause odor. |
|SS |Settle in the water bodies, cause septic condition |
|pH |Influence on aquatic organisms, erode drainage system or cause precipitation in the sewerage system |
|Temperature |Influence on aquatic organisms |
|Microorganism |Airborne diseases |
|Ammonia and phosphorus |Eutrophication |
|Colour |Aesthetic enjoyment |
|Oil and grease |Cause odor, prevent the oxygen diffusion and damage fish eggs |
The adverse effects of three alternatives in the acclimating phase are illustrated in the table 3-6.
Table 3-6: Adverse effects of three alternatives in the acclimating phase
|Alt1 – Facultative ponds |Alt2 – Trickling filter |Alt3 – Oxidation ditch |
|Odor caused by anaerobic degradation |It takes 3-4 weeks for building the biofilm ( |It is similar to trickling filter but the |
|Algea grew in the filling phase |the quality of treated water is not stable. |acclimating time is much shorter. |
|However, it does not influence on receivers due| | |
|to long retention time. | | |
2 Operational stage
In the operational and maintenance stages, the project may bring the positive impacts on the local environment, in particular, and Quy Nhơn city, in general. These adverse impacts will occur if there are incidents or mistakes in the operation of the plant. These impacts are defined as following:
1 Positive impacts
These positive impacts when the plant is operated are:
- Improve quality of surface water in Hà Thanh river in comparison with the scenario of without treatment
- Increase quality of the environment in Quy Nhơn city
- Improve public health thanks to ensuring hygienic conditions
- Reclaim the cultivated land using sludge from the plant, if it is satisfied the requirements of the standard of sludge quality.
- Provide work opportunities for local people in both construction and operational stages
2 Adverse impacts
Impacts of septage transport
The plant will receive the septage from the households in the Quy Nhon city together with the domestic wastewater. The septage loading is calculated based on the served population by 2023. The rate of septage production is 0.227 m3/year/capita. With the average distance of transporting septage of 10km, it requires 22 turns of 5m3 septage truck with the total length is 440km. The impacts of septage transporting may include:
- Air quality degradation due to dust emission from the construction of the sewers/drains.
- Air emission from transportation vehicles and construction equipment
- Additional quantity of CO, HC, NO2 emitted from vehicles due to traffic congestion caused by construction
- Odor problems associated with the collection and transportation of dredged sludge.
- Noise from construction vehicles and equipment (pavement breaker, compressor) and piling work
- Vibration from construction vehicles and equipment, and piling work.
Impacts on the surface water environment
Because the discharge of treated water into Hà Thanh river and Thị Nại lagoon will affect directly these water bodies, scenarios are constructed to predict impacts of all cases. The simulation is extremely important because Thị Nại lagoon is highly biodiverse and accordingly meaningful to aquaculture of local people. However, this report cannot model the water quality in Thi Nai lagoon due to the lack of the hydraulic profile and baseline data of the Thi Nai lagoon. Provided the declined pollution loads from the current outlets of untreated wastewater from elsewhere in the catchment, it is impossible at this stage to make a conclusion on potential adverse impacts caused by the project on Thi Nai lagoon. As a result, a regular monitoring of water quality in the lagoon is recommended.
These following scenarios are proposed to cover all cases could be happened in practice.
- Scenario a). Without treatment.
- Scenario b). Primary treatment only. This case represents for the operational incidents in artificial biological process. Wastewater is discharged directly into receiving water after going through the primary treatment.
- Scenario c). Starting-up period. The performance of the plant is the total of full performance of the primary treatment and 20% of secondary treatment.
- Scenario d). Maintenance period. The efficiency of biological treatments is 50%
- Scenario e). Work in the full capacity. Treated water is satisfied the TCVN 7222:2002.
This area has a complicated profile of tide because it is near the river mouth which is influenced by both river tide and sea tide. Therefore, the model is constructed in two regimes of tide in Hà Thanh river: flood-tide regime and ebb-tide regime. However, due to the lack of data about the hydraulic regime, the report uses the QUAL2K model to predict the impacts rather than using complicated models. It is assumed that the river section at which effluent and river water is completely mixed is the outlet.
The inputs of the model are based on the designed parameters of the CEPT plant.
Table 3-7: Inputs of the model
| |Phase 1A |Phase 1B |Phase 2 |
|Designed year |2013 |2018 |2023 |
|Designed flow-rate (m3/day) |7,000 |14,000 |28,000 |
|Initial BOD concentration a (mg/l) |333 |333 |333 |
|Initial total nitrogen concentration b (mgN/l) |80.00 |80.00 |80.00 |
|Initial Coliform concentration b (MPN/100mL) |1.0E+08 |1.0E+08 |1.0E+08 |
a Designed value of the plant.
b Metcaft and Eddy, 1991
The hydraulic profile and the baseline data of Ha Thanh river are presented in table 1.
Table 3-8: Baseline data of Hà Thanh River in the model
|Parameter |Flood-tide |Ebb-tide |
|Temperature T |oC |25 |25 |
|DO |mg/L |4.6 |4.6 |
|BOD5 |mg/L |2.4 |2.4 |
|H |m |0.84 |0.403 |
|Velocity U |m/s |0.163 |0.080 |
|Flow-rate Q |m3/s |19.4 |3.45 |
|Salinity S |Ppt |10.4 | |
Sources: Monitored by the PMU and the consultants (12/2005-01/2006)
BOD, COD and Coliform are modeled for each scenario in the dry season in the flood-tide regime and ebb-tide regime. Because the alternative 2 and the alternative 3 share the same performances of primary treatment and secondary treatment, only alternative 2 is considered and the results will be applied in the other. The model is calculated in two phases of the plant: Phase 1A as designated (7000m3/day) and Phase 2 (28000m3/day) when the plant has to serve the whole watershed. Hydraulic modeling of receiving water quality has been simulated for three alternatives of the secondary treatment. The proposed alternatives are facultative pond, trickling filter, and oxidation ditch. The selected parameters for the modeling are DO and total coliform. The simulation of DO takes into account both of CBOD (carbonaceous BOD) and TKN. The alternatives are analyzed for effluent dispersion of no treatment, only primary treatment with CEPT, start-up period at 20% of capacity, maintenance period at 50% of capacity, and full capacity. The modeling results are presented in the Annex D.
Table 3-9: Summary of the modeling result of the effluent dispersion in Ha Thanh river
|Item |Facultative Pond |Tricking Filter |Oxidation ditch |
|Recovery zone of BOD5, DO, and total coliform against | | | |
|TCVN 5942-1995 (column B) in dry season (distance, km): | | | |
|+ Low tide: | | | |
| BOD5 |0 (**) |0 (**) |0 (**) |
| DO |0 (**) |0 (**) |0 (**) |
| Total coliform |0 (**) |3.3 |3.3 |
|+ High tide: | | | |
| BOD5 |0 (**) |0 (**) |0 (**) |
| DO |0 (**) |0 (**) |0 (**) |
|Total coliform |0 (**) |0 (**) |0 (**) |
|Recovery zone of BOD5, DO, and total coliform against | | | |
|baseline of Ha Thanh river in dry season (distance, km):| | | |
|+ Low tide: | | | |
| BOD5 |4.6 |6.2 |5.1 |
| DO |2.0 |3.0 |2.5 |
| Total coliform |0 (***) |5.8 |5.8 |
|+ High tide: | | | |
| BOD5 |2.5 |3.5 |2.5 |
| DO |8.0 |10.0 |8.5 |
| Total coliform | 0 (***) |4.2 |4.2 |
|Values of BOD5(mg/L), DO (mg/L), and total coliform | | | |
|(No./100 mL) against baseline of Ha Thanh river outfall | | | |
|in dry season: | | | |
| BOD5 |3.6 |4.7 |4.7 |
| DO |4.7 |4.6 |4.6 |
| Total coliform |2.2x103 |1.3x104 |1.3x104 |
When WWTP runs at full capacity, the effluent quality would meet the national effluent standards TCVN 7222-2002. However, this standard does not mention the limited number of pathogen. It is assumed that the river segment is complete mixing in the modeling of effluent dispersion.
In the worst case (at low tide in the dry season), BOD5 and DO of river water at the outlet would meet TCVN 5942-1995 for all alternatives. However, in the cases of the oxidation ditch and trickling filter alternatives, coliform numbers of the river segment from the outlet to outfall to Thi Nai lagoon are not met the standards.
In comparison to river water quality baseline, at high tide, (the flow from outlet towards upstream), DO of the river water would be recovered at the distance of 8.0 km, 10 km, 8.5 km for facultative pond, trickling filter and oxidation ditch, respectively. Coliform number would be recovered at the distance of 4.2 km for both the trickling filter and oxidation ditch alternatives. Therefore, if trickling filter or oxidation ditch is selected, the disinfection before discharging into Ha Thanh river should be considered. If the land is available, the facultative pond should be the first priority.
The modeling result presents that at low tides (the flow from outlet towards Thi Nai lagoon), DO and BOD values of the Ha Thanh river water at the river outfall for all alternatives are still better than that of baseline of lagoon water. Whereas, total coliform number for both the trickling filter and oxidation ditch alternatives is higher than that of baseline.
The model was simulated scenarios in the dry season due to the lack of hydraulic data of Ha Thanh river in the rainy season. The flowrate of Ha Thanh river in the rainy season, may be tripled than that in the dry season. Therefore, the negative impacts of effluent of CEPT WWTP on the Ha Thanh river water quality will be decreased significantly.
Operational Incidents
Negative impacts during operation period are normally happened in case of the treatment system has problem. Problems happen during operation can significantly impact to environment, receiving water resources and human’s health, especially operation workers.
Impacts on the groundwater environment
Event though, underground water quality in this area can not be used for domestic use due to salinity intrusion, the discharge of organic substance into this water resources will cause a long term impacts upon the water resources in the area, especially to the areas having complicated changes in term of hydrogeology. The treatment and lining is necessary to mitigate possibility of pollution spreads.
Impacts to underground water environment only happen in facultative ponds. In case the reservoir is not bottom-lined, sewage with high organic and micro organic concentration will penetrate into soil and cause the underground water polluted. Although underground water quality in the area can not be used for drinking because of salinity intrusion, the discharge of organic compounds can result in a high loading of pollutants into the groundwater stream.
Table 3-10: Potential accidents in the operational activities of secondary treaments
|Facultative ponds |Trickling filter |Oxidation ditch |
|Impacts |Cause |Impacts |Cause |Impacts |Cause |
|Algae blooming |Shallow water |Increased concentration |High hydraulic loading |Bulking sludge |Mixing capacity is |
| |Bad maintenance |of SS in the outlet |Nitrification | |not enough. |
| | | |Huge amount of excess | |High F/M |
| | | |sludge split out | |Low pH |
| | | |Uneven distribution of | |Lack of nutrients |
| | | |untreated water and | | |
| | | |collection of treated | | |
| | | |water | | |
|Mouse |Lack of clearance of |Odor |High organic loading |Foaming |In the start-up phase|
| |lakeshore | |Bad circulation | |Short SRT ( lack of |
| | | | | |sludge in the ditch |
| | | | | |Low MLSS |
| | | | | |High pH |
| | | | | |Lack of DO |
|Groundwater pollution |Bottom cover is leaking |High BOD at the outlet |High SS |Fine sludge ( high SS|High SRT |
| | | |High organic loading | |High loading of |
| | | | | |clarifier |
|Scum |Rising bottom sludge | | |Scum |Low F/M |
| |High concentration of | | | |Norcadia existed |
| |oil and grease | | | | |
| |Uneven distribution and | | | | |
| |collection of water | | | | |
|Odor |Low pH (2500 |
|Lead (Pb) |0-200 |200-500 |500-1000 |1000-5000 |>5000 |
|Cadimi (Cd) |0-1 |1-3 |3-10 |10-50 |>50 |
Source: Extracted form Kelly Indices’s Standard (Former)
Standards on the concentration of heavy metals in the sludge in the developed countries
Unit: mg/kg
|Country |Year |Cd |Cu |
|A |pH :3 samples |BOD :3 samples |TS:1 sample |
| |DO :2 samples |TSS :3 samples |VS:1 sample |
| |Temperature :1 sample |pH :1 sample | |
| |Total coliform :1 sample |TKN :1 sample | |
| | |NH3 :1 sample | |
| | |DO :1 sample | |
|B |pH :4 samples |BOD :2 samples |TS:1 sample |
| |BOD :2 samples |TSS :2 samples |VS:1 sample |
| |TSS :2 samples |TKN :1 sample | |
| |DO :2 samples |NH3 :3 samples | |
| | |DO :1 sample | |
| | |TS :1 sample | |
| | |VS :1 sample | |
|C |pH :2 samples |BOD :2 samples |TS:1 sample |
| |MLSS :1 sample |TSS :2 samples |VS:1 sample |
| |SVI :1 sample |TKN :1 sample | |
| |BOD :1 sample |NH3 :2 samples | |
| |TSS :1 sample |pH :1 sample | |
| | |DO :1 sample | |
Appendix O. O&M COST
The cost of the operation and maintenance of the plant depends on the selected alternative. It is calculated as following:
The O&M cost of the alternative 2 (trickling filter) was estimated in Volume 1 of the Report on Project of CEPT WWTP investment. The O&M costs are described as follows
Labour cost: 378 million VND/year
- Worker: (10 workers) x (1 million VND/month) x (12 months) x (1.5) = 180 million VND
- Technical staff: (3 Technical staff) x (2 millions/month) x (12 months) x (1.5) = 108 million VND
- Director: (1 Director) x (5 million VND/month) x (12 months) x (1.5) = 90 million VND
Energy cost: 722 million/year
(55kW) x (1500 VND/kW) x (8760 (hours/year) = 722 million VND
Chemical cost: 1040 million VND/year
Aluminum = (533 kg/day) x (4200 VND/kg) x (365 days/year) = 848 million VND
Polymer = (17.5 kg/day) x (30,000 VND/kg) x (365 days/year) = 192 million VND
Maintenance cost: 981 million VND/year
(19,620 millions) x 0.05 = 981 million VND
The O&M costs of the Alternative 1 (stabilization pond) and Alternative 3 (Oxidation ditch) are estimated based on those of Alternative 2, difference of energy consumption of treatment process (Figure 7-1) and percentage of energy use for unit process (Figure 7-2).
[pic]
Comparison of electrical energy used for different types of treatment processes as a function of flowrate
(Source: Metcaft and Eddy, 2003)
[pic]
Distributions of energy usage in a typical wastewater treatment plant employing the activated-sludge process
(Source: Metcaft and Eddy, 2003)
Table 7-2 shows annually O&M costs for three alternatives. The value of 0.65 and 0.15 mean that the energy consumption of trickling filter and facultative pond is equal 65% and 15% of that of oxidation ditch, respectively.
Annually O&M costs for three alternatives (in million VND/year).
| |Alternative 1 (A1) |Alternative 2 (A2) |Alternative 3 (A3) |
|Labour cost |378 |378 |378 |
|Energy cost |[pic] |722 |[pic] |
|Chemical cost |1040 |1040 |1040 |
|Maintenance cost |[pic] |981 |[pic] |
|Total cost |1818 |3123 |4038 |
|Unit cost (VND/m3 of |712 |1222 |1580 |
|treated water) | | | |
Note: Energy cost: [pic] Maintenance cost: [pic]
[pic]
-----------------------
ENHANCED CHEMICAL TREATMENT
FACULTA䥔䕖倠乏⁄റ䄍䅎剅䉏䍉匠䑅䵉久䅔䥔乏倠乏ൄ䄍剉匠剔偉䥐䝎問䱔呅䅆啃呌呁噉⁅佐䑎㈠潃条汵湡൴䄍楮湯倠汯浹牥ഠ匍汯摩眠獡整伍潤൲匍畬杤摏牯ഠ伍潤䴍獯畱瑩敯䜍潲湵睤瑡牥瀠汯畬楴湯ഠ䴍獯畱瑩敯䜍潲湵睤瑡牥瀠汯畬楴湯ഠ伍潤൲伍潤൲潍煳極潴獥ഠ圍呁剅䤠呎䭁⁅⠍䍓䕒久义⭇啐偍义⁇呓呁佉⥎䅗䕔⁒义䅔䕋⠍䍓䕒久义⁇啐偍义⁇呓呁佉⥎久䅈䍎䑅䌠䕈䥍䅃⁌剔䅅䵔久ൔ名䥒䭃䥌䝎䘠䱉䕔䄍䅎剅䉏䍉匠䑅䵉久䅔䥔乏倠乏ൄ䄍剉匠剔偉䥐䝎問䱔呅䱃剁TIVE POND 1
ANAEROBIC SEDIMENTATION POND
AIR STRIPPING
OUTLET
FACULTATIVE POND 2
Coagulant
Anion Polymer
Solid waste
Odor
Sludge
Odor
Odor
Mosquitoes
Groundwater pollution
Mosquitoes
Groundwater pollution
Odor
Odor
Mosquitoes
WATER INTAKE
(SCREENING+PUMPING STATION)
WATER INTAKE
(SCREENING + PUMPING STATION)
ENHANCED CHEMICAL TREATMENT
TRICKLING FILTER
ANAEROBIC SEDIMENTATION POND
AIR STRIPPING
OUTLET
CLARIFIER
Coagulant
Anion Polymer
Solid waste
Odor
Sludge
Odor
Odor
Mosquitoes and insects
Odor
Odor
Mosquitoes and insects
Excess sludge
ENHANCED CHEMICAL TREATMENT
OXIDATION DITCH
ANAEROBIC
SEDIMENTATION POND
OUTLET
CLARIFIER
Coagulant
Anion Polymer
Solid waste
Odor
Sludge
Noise
Odor
Odor
Mosquitoes and insects
Sludge
Excess sludge
WATER INTAKE
(SCREENING+PUMPING STATION)
ENHANCED CHEMICAL TREATMENT
FACULTATIVE POND 1
ANAEROBIC SEDIMENTATION POND
AIR STRIPPING
OUTLET
FACULTATIVE POND 2
Coagulant
Anion Polymer
Solid waste: 1.4 m3 /day
sand: 0.4 m3 /day
SS:2570 tons/year
Dredging sludge:192 tons/year
SS: 128mg/L
WATER INTAKE
Wastewater +
sludge from septic tank
SS:320 mg/L
SS:390 mg/L
SS: 50mg/L
WATER INTAKE
ENHANCED CHEMICAL TREATMENT
TRICKLING FILTER
ANAEROBIC SEDIMENTATION POND
AIR STRIPPING
OUTLET
CLARIFIER
coagulant
Anion Polymer
Solid waste: 1.4m3/day
Sand: 0.4 m3/day
SS : 3070 tons/year
Excessive sludge
SS: 500 tons/year
Wastewater + sludge from septic tank
SS : 320 mg/L
SS : 390 mg/L
SS : 120 mg/L
SS : 50 mg/L
ENHANCED CHEMICAL TREATMENT
OXIDATION DITCH
ANAEROBIC SEDIMENTATION POND
OUTLET
CLARIFIER
coagulant
Anion Polymer
SS : 3160 tons/year
NOISE
SS : 390 mg/L
Circulated sludge
Excessive sludge
SS: 585 tons/year
WATER INTAKE
Wastewater + sludge from septic tank
SS : 320 mg/L
Solid waste:1.4m3/day
Sand : 0.4 m3/day
SS : 120 mg/L
SS : 50 mg/L
World Bank
Socialist Republic of Vietnam
[pic]
QUY NHON CITY ENVIRONMENTAL SANITATION SUB-PROJECT
(CEPT)
WB, DONRE and other authorities
Project Management Unit (PMU)
WWTP plant (Water supply and drainage company)
Independent Safeguards Monitoring Consultant (ISMC)
Contractors implementing mitigation measures
CMC
................
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