subproject feasibility study - svk gms-ewec td pdr: greater mekong subregion corridor towns...

Lao PDR: Greater Mekong Subregion Corridor Towns Development Project i

Subproject Feasibility Study Kayson Phomvihane Wastewater Treatment

Final Report

Lao PDR: GMS Corridor Towns Development Project

Subproject Feasibility Study

ADB TA 7644-REG

November 2012

Prepared for the Asian Development Bank and the Ministry of Public Works

and Transport by Norconsult AS

Kaysone Phomvihane

WASTEWATER TREATMENT

ii Lao PDR:Greater Mekong Subregion Corridor Towns Development Project


Subproject Feasibility Study Kaysone Phomvihane Wastewater Treatment

Lao People‟s Democratic Republic

EXECUTIVE SUMMARY

The opening of the cross border trading and exchanges in goods and services stimulated the growth of the business sector as well as expanded the urban areas in the town Kaysone Phomvihane. The local economy of the town is largely influenced by its strategic location at the border of Lao PDR and Thailand which has contributed to increase in trade and commerce. The town‟s population of 76,905 with a relatively high population density created demands for adequate urban infrastructure particularly solid waste management, wastewater treatment, flood protection measures and improvement of urban roads. The major concentration of the population has been in the old town center adjacent to the Mekong River.

The present wastewater management practice in the town center and the immediate vicinities in Kaysone Phomvihane involve individual treatment by the households and commercial establishments using pour-flush or dry latrines and septic tank for liquid waste disposal and soak pits for grey water disposal that overflow to the open storm water drains. Wastewater from household usage such as shower, laundry including food preparation, is mostly directly discharged to the storm water drainage system without any treatment. There is no grease trap installed for pre-treatment of grease and oil that flows out from daily households and local enterprise activities. Small scale industries normally discharge their waste directly to the drainage system with some simple treatment such as storage tank only. The inefficient installation of the effluent pipe from septic tank is causing leakage of sewer thus polluting the soil and ground water. During the period covering 2007 to 2008, approximately 14,000 cubic meters a day of wastewater is generated and drained to the open drainage structures with the expanding urban areas and the increasing number of households, the quantity of sewerage is expected to increase resulting in higher pollution load flowing to the Mekong River each year.

The improvement of the drainage and sewage networks and the establishment of the Wastewater Treatments will mitigate contamination of the local environment and reduce health risks of the urban population. The proper draining of the storm water into the rehabilitated canals and the construction of sewage pipelines at the bottom of the canals are crucial to avoid pollution of the open areas and to mitigate environment related problems.

The Kaysone Phomvihane Wastewater Treatment subproject is intended to mitigate the contamination of the local environment and reduce health risk of the local population. The specific objective of the subproject is to improve and upgrade the storm water drainage network and sewerage pipelines from the town center leading to the sites of the new Wastewater Treatments. The subproject will contribute to making Kaysone Phomvihane an attractive and competitive town in EWEC. The total investment cost of the Wastewater Treatment subproject amounts to $4.98M of representing the direct cost for the civil works for drainage canals, sewerage pipelines and the WWTP.

The Kaysone Phomvihane Wastewater Treatment subproject will involve the improvement of existing storm water drains, construction of sewerage interceptor pipelines and the installation of new wastewater treatments in 3 separate locations. The major components are:

Civil works for the improvement of existing storm water drainage networks along the river streams in the northern, central and southern portion of the town center.

Installation of sewage interceptor pipelines at the bottom of the storm water drains.

Extension of sewage interceptor pipelines to the site of the wastewater treatment.

Lao PDR:Greater Mekong Subregion Corridor Towns Development Project iii


Installation of drainage pumps as flood control measures.

Establishment of 3 new wastewater treatments in the northern, central and southern locations.

The Project Management Unit (PMU) which will be established in the Province of Savannakhet‟s Provincial Department of Public Works and Transport (PDPWT) will ensure that the implementation of all civil works and construction activities related to the WWTP subproject strictly comply with relevant national and local issuances and regulations during the course of subproject implementation. The PMU through the Project Implementation Team (PIT) established in Kaysone Phomvihane will regularly monitor the compliance of the subproject implementation in relation to the ADB guidelines and agreed work plans and schedule of activities.

The results of the economic and financial analysis indicate that the subproject has an FIRR of 4.29% and NPV of $2.97 million; EIRR of 27.07% and NPV of $1.95 million; and poverty impact ratio of 26%.

The Initial Environmental Examination (IEE) took into consideration the preliminary subproject design, the baseline environmental conditions, possible impacts and mitigation measures and institutional arrangements to implement the subproject. Based on the IEE report, the Kaysone Phomvihane Wastewater Treatment subproject is assigned a Category “B” under ADB classification.

The Kaysone Phomvihane Wastewater Treatment subproject will uplift the quality of life and upgrade the living conditions of the town‟s population through the improvement of storm drainage canals, installation of separate sewerage pipelines and construction of a new wastewater treatment plant. Socio-economic benefits will accrue to 80% of the population since the subproject will minimize health risks caused by unsanitary environment. It will also reduce the exposure of women and children to waterborne illnesses caused by the overflow of open drainage canals and leaking of sewerage pipes, which often carry storm water run-offs and wastewater.

The subproject will contribute to enhance economic activities for local residents and business establishments. Vulnerable population and women in Kaysone Phomvihane will be afforded with employment opportunities from increased trade and investments as a consequence of good wastewater management.

iv Lao PDR:Greater Mekong Subregion Corridor Towns Development Project


ABBREVIATIONS AND ACRONYMS

ADB Asian Development Bank ADF Asian Development Fund AFD Agence Francaise de Developpement BOT Build Operate Transfer CTDP Corridor Towns Development Project DDG Deputy Director General DHUP Department of Housing and Urban Planning DIPMC District Investment Promotion and Management Committee DMC Development Member Countries DOF Department of Finance DOPWT District of Office Public Works and Transport DPI Department of Planning and Investment DPMC-IS dual-power, multi-cellular intermittent sand filter system DPS Direct Purchase Shopping EA Executing Agency EDCP Economic Development Cooperation Fund EMP Environment Management Plan EWEC East West Economic Corridor F/M food/microorganism FC fecal coliform(s) FWS free water surface FYSEDP Five Year Socio Economic Development Plan GDP Gross Domestic Product GIS Geographic Information System GMS Greater Mekong Sub-Region HCR hydrogen controlled release HLT high level transfer HPAPS high performance aerated pond system HRP high rate pond HRT hydraulic residence time/hydraulic retention time HRT hydraulic residence time/hydraulic retention time I&I Inflow & Infiltration IA Implementing Agency ICB International Competitive Bidding IEE Initial Environment Evaluation IP Indigenous People IPDs in-pond digesters IS International Shopping JFPR Japan Fund for Poverty Reduction JICA Japan International Cooperation Agency JSF Japan Special Fund KEXIM Korea Export-Import Bank KfW Kreditanstalt für Wiederaufbau Lagoon-ISF Lagoon Intermittent Sand filter LAK Lao Currency Lao PDR Lao People‟s Democratic Republic LCB Local Competitive Bidding LECS-4 Fourth Lao Expenditure and Consumption Survey LWU Lao Women Union M metalion MBBRTM Moving Bed Biofilm Reactor MCRT mean cell resident time MFA Ministry of Foreign Affairs MIC Ministry of Industry and Commerce MLSS mixed liquor suspended solids

Lao PDR:Greater Mekong Subregion Corridor Towns Development Project v


MLVSS mixed liquor volatile suspended solids MOF Ministry of Financial MOU Memorandum of Understand MPI Ministry of Planning and Investment MPN most probable number MPWT Ministry of Public Works and Transport MRF Material Recovery Facilities MSL mean sea level MWRE Ministry of Water Resource and Environment NCB National Competitive Bidding NFB nitrification filter bed NGOs Non-Government Organization NH2-N ammonia-N, ammonia nitrogen NORAD Norwegian Agency for Development Cooperation NSEDP National Socio Economic Development Plan NUSS National Urban Sector Strategic O&M operation and maintenance OD oxygen demand ODA Official Development Assistant ODOP One District One Product OPEC Organization of Petrol Exporting Countries OSS One Stop Service PDPWT Provincial Department of Public Works and Transport PIPMC Provincial Investment Promotion and Management Committee PMS Project implementation support (PMS) consultants PIT Project Implementation Team PM Project Management PMU Project Management Unit POTWs Publicly owned treatment works PPMU Provincial Project Management Unit PPP Public Private Partnership PPTA Project Preparation Technical Assistance PSC Project Steering Committee PSEDP Provincial Social Economic Development Plan PTI Public Works and Transport Institute RAS return activated sludge RCIF Regional Cooperation and Integration Fund RO Reverse Osmosis RSP Rocks Slope Protection SAR Sodium adsorption ratio Sa-SEZ Savan SENO Economic Zone SCBOD5 soluble carbonaceous BOD5 SCCI Savanakhet Chamber of Commerce and Industry SCFM Standard cubic feet per minute SEZA Savan SENO Economic Zone Authority SF, SSF subsurface flow SFP secondary facultative pond SLEDP Strategic Local Economic Development Plan SMRFB Second Mekong River Friendship Bridge SPAR Subproject Appraisal Report SS Suspended solids STEP Septic tank effluent pumping system SVKP Savanakhet Province SWM Solid Waste Management SWOT Strength-Weakness-Opportunities-Treats TA Technical Assistance TACC Technical Advisory and Coordination Committee TFCC Total fecal coliform count

vi Lao PDR:Greater Mekong Subregion Corridor Towns Development Project


TKN Total Kjedahl nitrogen TP Total phosphorus TSS Total suspended solids TVSS Total volatile suspended solids UDAA Urban Development Administration Authority UFPF Urban Financing Partnership Facility UNDP United National Development Programme

BOD Biochemical oxygen demand

CCs Construction Contractors

CEDAW Convention on the Elimination of all forms of Discrimination against Women

DED Detail Engineering Design

DEMM Department of Energize and Mining Management

DGPS Digital Global Position Systems

ECO Environmental Control Officer

EGM Effective Gender Mainstreaming

EGM Effective Gender Mainstreaming

ESO Environmental Site Officer

FS Feasibility Study

GAP Gender Action Plan

GOL Government of Lao

GPS Global Position System

HDPE High Density Pipe

IEM Independent Evaluation Mission

IRR Internal Rate of Return

LAR Land Acquisition Resettlement

LCS Land Certificate System

LWU Lao Women Union

MCTPC Communication Transport Post and Construction

MREP Mekong River Embankment Protection

NCAW National Commission for Advancement of Women

NR9 National Road Number 9

PIT Project Implementation Team

PMSProject Implementation Support

PMU Project Management Unit

PPMS Project Performance Monitoring System

ROW Right Of Way

SBD Standard Bidding Documents

SDP Social Development Plan

SIDA Swedish International Development Agency

STEA Scientist Technology and Environmental Authority

SUDAA Savannakhet Urban Administration Authority

USD Urban Sector Development

WREA Water Resource Environmental Authority

WWTP Wastewater Treatment Plant

Lao PDR:Greater Mekong Subregion Corridor Towns Development Project vii


TABLE OF CONTENTS 1 DESCRIPTION OF THE STUDY AREA .......................................................................................................... 1

2 PROJECT RATIONALE, OBJECTIVES AND SCOPE ........................................................................................ 4

2.1 RATIONALE .................................................................................................................................................... 4 2.2 SUBPROJECT GOALS AND OBJECTIVES ................................................................................................................. 4 2.3 SUBPROJECT COMPONENTS .............................................................................................................................. 5 2.4 SCOPE OF CIVIL WORKS AND CONSTRUCTION ACTIVITIES........................................................................................ 5

3 Existing conditions ................................................................................................................................... 7

3.1 SUBPROJECT LOCATION ................................................................................................................................... 7 3.2 NATURAL FEATURES PHYSICAL CONDITIONS ......................................................................................................... 9 3.3 SOCIO- ECONOMIC CONDITIONS ...................................................................................................................... 12 3.4 EVENTUAL EXISTING PLANS FOR WWT ............................................................................................................. 14 3.5 URBAN AND ENVIRONMENTAL INFRASTRUCTURE ................................................................................................. 14 3.6 CONSULTATIONS AND SURVEYS ....................................................................................................................... 17 3.7 INSTITUTIONAL ARRANGEMENTS...................................................................................................................... 18

4 POPULATION GROWTH & DEMAND FORECASTS .................................................................................... 20

4.1 DESIGN HORIZONS ........................................................................................................................................ 20 4.2 POPULATION AND DEMAND FORECASTS ............................................................................................................ 20 4.3 DEMAND-SUPPLY GAP ANALYSIS ...................................................................................................................... 22

5 TECHNICAL SOLUTIONS .......................................................................................................................... 24

5.1 STANDARDS, GUIDELINES AND FORMAL REQUIREMENTS ....................................................................................... 24 5.2 SURVEYS AND TECHNICAL REFERENCE MATERIALS ............................................................................................... 30 5.3 DIMENSIONING - DESIGN CRITERIA ................................................................................................................... 31 5.4 TECHNICAL ANALYSIS - OPTIONS AND FEASIBILITY ASSESSMENT .............................................................................. 35 5.5 CONCEPTUAL ENGINEERING SOLUTIONS AND DESIGN ........................................................................................... 46 5.6 CIVIL AND STRUCTURAL DESIGN CRITERIA AND BASIS ........................................................................................... 57

6 COST ESTIMATES .................................................................................................................................... 62

6.1 SUBPROJECT INVESTMENT COSTS ..................................................................................................................... 62 6.2 OPERATIONAL AND MAINTENANCE COSTS .......................................................................................................... 74

7 Project management.............................................................................................................................. 76

7.1 SUBPROJECT IMPLEMENTATION ....................................................................................................................... 76 7.2 IMPLEMENTATION SCHEDULE .......................................................................................................................... 76 7.3 PROCUREMENT ARRANGEMENTS AND PACKAGES ................................................................................................ 78 7.4 MONITORING REQUIREMENTS AND ARRANGEMENTS ........................................................................................... 78

8 SUBPROJECT APPRAISAL ............................................................................... Error! Bookmark not defined.

8.1 INSTITUTIONAL ARRANGEMENTS.......................................................................... ERROR! BOOKMARK NOT DEFINED. 8.2 FINANCIAL FEASIBILITY ................................................................................................................................... 86 8.3 ECONOMIC FEASIBILITY .................................................................................................................................. 90 8.4 ENVIRONMENTAL ASPECTS ............................................................................................................................. 95 8.4.1 PRELIMINARY IDENTIFICATION OF ENVIRONMENTAL IMPACTS AND MITIGATION MEASURES ................................. 95 8.5 SOCIAL ASPECTS ........................................................................................................................................... 97 CONSULTATION AND PARTICIPATION DURING RESETTLEMENT PLAN PREPARATION ....................................................... 102

9 CONCLUSION ....................................................................................................................................... 104

List of Annexes

Annex 1 : ..................................................................................................................................................... 107

Annex 2 : Layouts, longitude sections and design analysis for the southern wastewater system ................ 109

Annex 3 Wastewater treatment ponds - design criteria, analysis and calculations ................................... 112

Annex 4 Requirements - materials .............................................................................................................. 117

Annex 5 - Requirements for Aggregates ...................................................................................................... 118

Annex 6 Requirements for civil/construction works ................................................................................... 119

Annex 7 - Drawings................................................................................................................................... 122

viii Lao PDR:Greater Mekong Subregion Corridor Towns Development Project


LIST OF FIGURES Figure 1: Location Map of Kaysone Phomvihane ................................................................................ 3 Figure 2: Kaysone Phomvihane Subproject Location Map .................................................................... 8 Figure 3: Seismicity Distribution Map for Seismic Design .................................................................. 10 Figure 4. Population zoning and density for next decade of Kaysone Phomvihane ........................... 21 Figure 5. Distribution of Monthly Rainfall of Savannakhet Meteorological gauging Station ............. 32 Figure 7: Runoff Analysis of Short Duration High Rainfall Intensity ............................................... 33 Figure 8: Typical overflow interceptor sewer ....................................................................................... 36 Figure 9: Manhole for maintenance of the sewerage pipe with 50m spacing ....................................... 38 Figure 10: Storm drainage with the sewerage pipe ............................................................................... 39 Figure 12: Typical Aerated Wastewater Treatment Plant ..................................................................... 41 Figure 13: Typical Aerated Wastewater Treatment Plant ..................................................................... 41 Figure 15: Typical stop gate and drainage pump station ...................................................................... 43 Figure 16: Typical Interceptor Sewer Concept in Northern system ..................................................... 45 Figure 17: Overall Plan and Layout of Kaysone Phomvihane drainage and wastewater treatment

system ................................................................................................................................................... 47 Figure 20: Structure of Subproject Implementation and Management ................................................ 83

LIST OF TABLES Table 1: GDP in 2006-2009 and Estimate from 2010-2014 ................................................................. 12 Table 2: Household divide into economic sector .................................................................................. 13 Table 3: Population Projection 2015-2030, Kaysone Phomvihane...................................................... 20 Table 4: Population forecasted of projected services area ................................................................... 22 Table 5: Authorized Surface Water Quality Standard ....................................................................... 25 Table 6: Authorized Standards for Wastewater Discharge in Urban Area in Lao PDR ...................... 26 Table 7: Permissible Values for Wastewater Discharge in urban area in Lao PDR ............................ 28 Table 8: Building/Wastewater Source Categorization ........................................................................ 29 Table 9: Basic Statistic of the Savannakhet's meteorological data ....................................................... 31 Table 10: Average Daily Wastewater Generation ............................................................................... 35 Table 12: Specific specification requirement for geotextiles ............................................................ 59 Table 13: Cost analysis for the Kaysone Phomvihane Wastewater Treatment Subproject. ................. 63 Table 14: Costs estimate for Southern Houay Longkong drainage System sub-site ........................... 65 Table 15: Costs estimate for Central drainage system around the Savanxay Market sub-site .............. 68 Table 16: Costs estimate for Northern Houay Khilamang drainage system sub-site ............................ 71 Table 17 : Costs estimates for operational and maintenance wastewater management system. .......... 75 Table 19: Indicative Composition of the PMU Management and Staff .................................................. i Table 20: Composition of the PIT Management and Staff, Kaysone Phomvihane ............................. 82 Table 21: Total Investment and Financing Plan ($million) .................................................................. 87 Table 23: Computation of Weighted Cost of Capital (WACC) ............................................................ 89 Table 24: Result of Financial Internal Rate of Return and Net Present Value ..................................... 89 Table 26: Economic Cost Assumptions ................................................................................................ 92 Table 27: Summary of Economic Costs ($ million) ............................................................................. 92 Table 29: Summary Result of Economic Evaluation ............................................................................ 94 Table 30: Computation of Poverty Impact Ratio .................................................................................. 94 Table 31. Result of Economic Evaluation ............................................................................................ 94 .............................................................................................................. Error! Bookmark not defined. Table 33: Specific requirements for fine aggregates .......................................................................... 118 Table 34: Specific requirements for concrete aggregates .................................................................. 118

Lao PDR: Greater Mekong Subregion Corridor Towns Development Project 1


Subproject Feasibility Study Kaysone Phomvihane Wastewater Treatment

Lao People‟s Democratic Republic

1 DESCRIPTION OF THE STUDY AREA

The opening of the cross border trading and exchanges in goods and services stimulated the growth of the business sector as well as expanded the urban areas in Kaysone Phomvihane. The local economy of the town is largely influenced by its strategic location at the border of Lao PDR and Thailand, which has contributed to increase trade and commerce. The town‟s population of 76,905, a relatively high population density, created demands for adequate urban infrastructure particularly solid waste management, wastewater treatment, flood protection measures and improvement of urban roads. The major concentration of the population has been in the old town center adjacent to the Mekong River.

The process ofurbanization is moving rapidly in the town, owing to the improved transport network along the East-West Economic Corridor. This has resulted in the rapid increase in urban population and the growing demands for improved living standards among local residents and the business sector. The urbanization trends would continue in parallel with the establishment of small and medium industries that are now located in the Savan-SENO Special Economic Zone. With the anticipated growth of the local economy, the provincial and district authorities need to pursue adequate measures to respond to the growing demand for essential infrastructure to provide the requirements of urban sector development.

Kaysone Phomvihane is the provincial capital of Savannakhet and is the second largest town in Lao PDR. However, the urban environment and water quality of the surface water flowing through open canals further downward to natural streams has been getting worse. Water quantity has degraded due to inflow of domestic wastewater from urban areas as a consequence of the growing urban population and increasing economic activities. This urbanization trends would continue in parallel with infrastructural developments like industrial park of the Savan-SENO Special Economic Zone and the emergence of new urban areas within the immediate vicinity of the town center. The present wastewater management practice in the town center and the immediate vicinities in Kaysone Phomvihane involve individual treatment by the households and commercial establishments using pour-flush or dry latrines and septic tank for liquid waste disposal, and soak pits for grey water disposal that overflow to the open storm water drains. Wastewater from household usage such as shower, food preparation and laundry, is mostly discharged to the storm water drainage system without any treatment. There is no grease trap installed for pre-treatment of grease and oil that flows out from daily households and local enterprise activities. Small scale industries normally discharge their waste directly to the drainage system with some simple treatment such as storage tank. The inefficient installation of the effluent pipe from septic tank is causing leakage of sewer thus polluting the soil and ground water. During the period covering 2007-2008, approximately 14,000 cubic meters a day of wastewater is generated and drained to the open drainage structures with the expanding urban areas and the increasing number of households. The quantity of sewerage is expected to increase resulting in higher pollution load flowing to the Mekong River each year.

The improvement of the drainage and sewage networks and the establishment of the wastewater treatments will mitigate contamination of the local environment and reduce health risks of the urban population. The proper draining of the storm water into the rehabilitated canals and the construction of sewage pipelines at the bottom of the canals are crucial to avoid pollution of the open areas and to mitigate environment related

2 Lao PDR:Greater Mekong Subregion Corridor Towns Development Project


problems. The rehabilitation of existing storm water drainage canals will cover the southern, central and northern part of the Kaysone Phomvihane. In the southern part, the existing canals along Houay Longkong stream shall be improved. The storm water drainage canal in this southern part has a catchment area of 538 hectares. The central drainage canals, which are installed around the Savanxay Market and along Chemkeo stream has a catchment area of 81 hectares. The northern drainage canals located along the Houay Khilamang stream has a catchment area of 500 hectares. The storm water drainage canals and the sewage pipelines will flow to the three new wastewater treatments which are to be established in strategic sites. These essential urban environment infrastructures will benefit more than 80% of the total households in the area. .

The ADB has provided technical and financial assistance to the national government in the implementation of wastewater treatment projects. In 1993, ADB financed the Vientiane Integrated Urban Development Project, which has a wastewater treatment component involving the rehabilitation of storm water drainage structures. Under the ADB-funded Secondary Towns Development Project, the town of Kaysone Phomvihane was assisted in the improvement and upgrading of roads and storm water drainage structures. This assistance did not include the establishment of wastewater treatments.

Lao PDR:Greater Mekong Subregion Corridor Towns Development Project 3


Figure 1: Location Map of Kaysone Phomvihane

Source: GMS Corridor Towns Development Project. (TA 7644-REG)



2 PROJECT RATIONALE, OBJECTIVES AND SCOPE

2.1 Rationale

The District Authority of Kaysone Phomvihane and the Provincial Department of Public Works and Transport (PDPWT) fully recognize the need for upgrading and expanding urban infrastructure and essential services to cope with urbanization and economic growth. Local authorities acknowledge the strategic location of Kaysone Phomvihane as a competitive advantage to attract investments from public and private sector and spur economic activity. The economic trade and investments are expected to increase as a consequence of the improved road and transport network along NR9 and the opening of the border crossing between Lao PDR and Thailand and Vietnam. The town is now faced with a challenge of coping up with the rapid growth of the urban sector and of meeting the demands of an increasing urban population for adequate urban infrastructure.

The town center of Kaysone Phomvihane is having problems associated with unsanitary environment brought about by the inadequacy of essential urban infrastructure. The threat of seasonal severe pollution of the local environment and flooding events will adversely affect the socio-economic conditions in the town. Local residents, specifically the poor and other vulnerable groups, will be exposed to health hazards associated with poor environmental sanitation. Continued growth of the urban population of the town will put considerable pressure on the local authorities to provide the required infrastructure to mitigate the perennial environment concerns.

A sound environmental sanitation entails proper collection, transport and disposal of waste into storm water drainsand sewage pipelines leading to a wastewater treatment. Majority of the households in the area rely on water flush latrines that are connected to a pit or chamber, for containment of excreta. However, due to the low permeability of the soil and the high groundwater table around the town, many soakaways fail to operate effectively resulting in discharge of sewage from tanks into drainage channels or low lying areas. This practice results in the flow polluted effluents in the open storm water drains which will cause environmental degradation and health hazards.

Local authorities recognize that improving and constructing storm water drains and sewage pipelines, and the installation of the treatment plant are essential measures to mitigate the contamination of the local environment and reduce health risks of an increasing urban population. Proper and systematic collection, transport and disposal of wastewater to a treatment plant are crucial to avoid pollution of the open areas and mitigate health and environment related problems. This urban environment infrastructure will contribute to uplifting the living standards of more than 80% of the local residents and will attract more private sector investments in Kaysone Phomvihane.

The improvement of the storm water drainage network and sewage pipeline, and the establishment of new wastewater treatments are among the priority urban infrastructure projects identified in the Kaysone Phomvihane Strategic Local Economic Development Plan. The Provincial and District authorities have endorsed this urban infrastructure to MPWT for priority investment support under the ADB-assisted GMS Corridor Towns Development. The improvement of the wastewater management and the establishment of new wastewater treatments will contribute to the attainment of the development vision of Kaysone Phomvihane to become the international and regional economic center for increased trade and traffic flows of people, goods and services along the East West Economic Corridor in the Greater Mekong Sub-region.

2.2 Subproject Goals and Objectives

The Kaysone Phomvihane Wastewater Treatment subproject is intended to mitigate the contamination of the local environment and reduce health risk of the local population. The specific objective of the subproject is to improve and upgrade the storm water drainage network and sewerage pipelines from the town center leading to the sites of the new



wastewater treatments. The subproject will contribute to make Kaysone Phomvihane an attractive and competitive town in EWEC.

It is expected that when the subproject is fully implemented, the town of Kaysone Phomvihane will serve as a model town of an effective system for the collection, disposal and treatment of wastewater in the province of Savannakhet.

2.3 Subproject Components

The Kaysone Phomvihane Wastewater Treatment subproject will involve the improvement of existing storm water drains, construction of sewerage interceptor pipelines and the installation of new wastewater treatments in three separate locations.

The subproject includes the following major components:

i) civil works for the improvement of existing storm water drainage networks along the river streams in the northern, central and southern portion of the town center,

ii) installation of sewage interceptor pipelines at the bottom of the storm water drains,

iii) extension of sewage interceptor pipelines to the site of the wastewater treatment,

iv) installation of drainage pumps as flood control measures, and v) establishment of three new wastewater treatments in the northern, central and

southern locations. In terms of the involuntary resettlement, the subproject is assigned Category B,

which implies that limited resettlement impact will be created with the implementation of the subproject. There will also be no resettlement issue in relation to the construction of the open and closed canals or the access roads, as there are existing structures at the same locations as the planned structures.

An essential subproject component is the provision of capacity building for operation, management and maintenance of the Kaysone Phomvihane Wastewater Treatment subproject to be undertaken by the Project Management Unit (PMU) for the PDPWT and UDAA.

2.4 Scope of Civil Works and Construction Activities

2.4.1 Houay Longkong Waste Water and drainage networks

The southern portion of Kaysone Phomvihane town is the Houay Longkong drainage network, identified as a priority area with environmental problems related to inappropriate drainage, inadequate sanitation, and limited access to services such as waste management. The lined open drainage canal constructed under the ADB-funded Secondary Towns Development Project was intended to improve the drainage structures for storm surface water. During the dry period, the wastewater from the households directly drain into the open canal without any pre-treatment.

The drainage canals then become sewerage stream that creates serious social and environmental problems. The low land topography of areas along the Houay Longkong stream causes flooding particularly when the water level of the Mekong River is high. The Houay Longkong drainage network has a catchment area of 538 hectares.

The improvement works for the drainage network on this southern portion will

involve the following:



Repair and rehabilitation of damaged storm water drains along existing open

canals.

Installation of sewage interceptorswith overflows and 2.5 km sewerage pipelines

on the bottom of the open storm drainage canals leading to the site of the

wastewater treatment.

Installation of a new wastewater treatment plant before discharge to Mekong River.

Construction of new 0.5 km open drainage canal with riprap slope erosion protection along the Houay Longkong stream.

Construction of new flood protection gates, preventing flood water from Mekong to enter the hinterland.

Installation of water pump station equipped with 2 pump units having a capacity not less than 0.5m3/s each, in order to pump out water from the upstream area to Mekong when the gates are closed.

Construction of erosion protection structures at the outlet of the Houay Longkong stream.

a. Central Wastewater and Drainage Network

The central drainage networks cover the Savanxay Market and bus terminal area

and adjoining commercial establishments and residential houses. As the central area, it is highly populated and the open canals are usually clogged with solid waste inadvertently disposed by local residents. The drainage network from the central area to the disposal site is about 1,600 meters. The local authorities and PDPWT have identified the upgrading and rehabilitation of the storm drains and sewage pipes including treatment measures prior to the discharge to the Mekong River.

The upgrading and rehabilitation works will involve the following scope:

i) construction of sewage pipes, culverts, manholes, gutters and related urban drainage structures along the existing drainage networks; and

ii) installation of a wastewater treatmentplant at the outlet of Chomekeo stream.

b. Houay Khilamang Wastewater and Drainage Network

The lower part of the northern drainage network along the Houay Khilamang stream lays on a relatively less populated area. Catchment at the end of the existing lined open canal is 5km2 and at the outlet of Houay Khilamang to Mekong River is 6.9km2. The upper catchment area is more densely populated at an estimated number of about 27,500 persons (2010 figure). The catchment area of this northern drainage network is 500 hectares where mechanical shops, factories, car washing and commercial establishments and residential houses are situated. The catchment area is also an emerging urban center due to increased economic activities.

The improvements of the drainage network in the northern system are:

i) Installation of a sewer interceptor with overflow and transport pipelines of approximately 700-750m in length with diameters ranging from 400 mm to the wastewater treatment.

ii) Construction of urban drainage structures measuring 1.130m(pipes culverts, manholes, gutters and chamber etc.) for area adjacent to the northern side of Savanxay Market drain to Houay Khilamang.

iii) Installation of wastewater treatment with surface aerated basin equipped with electric motor, propeller and slinger-ring on vertical shaft; and retention pondsafter that will serve as Natural Stabilisation Pond.



3 EXISTING CONDITIONS

3.1 Subproject Location

The improvement and rehabilitation of storm water drains and sewage pipelines will be undertaken in the 3 locations, as follows:

a. Houay Lonkong drainage network in the southern portion of the town center

The Houay Longkong is one of the natural streams for the discharge of wastewater without treatment from the town to the Mekong River. Wastewater drains to the Mekong River when the level of the river is lower. However, the wastewater is retained in the Houay Longkong stream when the river is high. This makes the wastewater stagnant on the stream creating foul odor that pollutes the air, causing inconvenience to the local residents.

The existing storm water drain canal network starts at the Chaymuang road and traverses in between Sisavangvong and Ratsavongseuk roads, crossing other road segments until it reaches Phokadouath road. The canal has a total length of 1.65km. The other open drain structure in the network is the 550m long canal starting at the crossing of Santiphap road in the eastern area of Houay Longkong stream and to the main canal located at the crossing with Xiengsa road. The remaining last drainage is natural Houay Longkong stream. The sewage and wastewater generated flow directly to the open drainage canals and remain stagnant for a while with both liquid and solid wastes before these are finally discharged without treatment to the Mekong River. The improvement and rehabilitation of open drains and sewage pipes will be designed to serve the anticipated increase in population up to 2030.

During the rainy season, the Houay Longkong stream overflows and flood waters remains on the stream when water level of the Mekong River is high. The situation where flood waters are contaminated by wastewater is adversely affecting the socio-economic conditions of the local residents and the business sector.

b. Central drainage networks around the Savanxay market and bus terminal area

The existing drainage structures in the central part of town are open storm water canals that are not properly maintained and regularly cleaned. Wastewater including solid waste often clogged the open canals. Wastewater drained from the market and bus terminal fill up the open canals with stagnant wastewater mixed with solid waste from the local residents. The drainage network is in the north-west section of Santiphap Road and north section of Sisavangvong road leading to the area of the bus terminal and the Savanxay Market. These areas are densely populated urban area. The drainages of this area are open trench, all coming from surface water through the side drainages. Wastewater flows directly into open trench passing through the side of Savanxay Market and draining into the main open drainage canal along Visoukan road.

c. Houang Khilamang drainage networks in the northern portion

The northern portion of Kaysone Phomvihane is a relatively populated area where most of the shops, including hotels and restaurants are situated. The carrying capacity of the current storm water drains and sewage pipes have become inadequate to accommodate the volume of daily wastewater generated by the growing number of urban residents and commercial establishments. This drainage system flows directly to Mekong River through the Chomkeo stream. The northern drainage system of Houay Khilamang stream‟s catchment covers about 500 hectares.



In the rainy season, the water level on the Mekong is highest during the months of August and September. The water level is about 1m below the road surface. The back water from Mekong River causes flooding in front of the flap gate culverts that were constructed for flood control measures.

Figure 2: Kaysone Phomvihane Subproject Location Map




3.2 Natural Features Physical Conditions

3.2.1 Resource Endowments

Kaysone Phomvihan, the provincial capital town, is within the catchment of the Savannakhet basin that is underlain by tertiary and quaternary sediments. The topography of the subproject area which covers almost the entire town center is characterized by generally flat to undulating lands with almost flat slopes to about 8 degrees. The soils comprise fine, alluvial silts, sands and clays deposited by floodwaters from the tributaries of Mekong River. Significant erosion of topsoil has been recorded in the region. Under the top soils are lateritic soils with organic matter. The Mekong River is the outlet of the wastewater discharged from the town center through the Houang Longkong, Chomkeo and Houang Khilang streams.

The emergence of the town started with the movement of people from the area facing the Mekong River, to the eastern and northern areas of what is now the town center. The completion of the Second Friendship Bridge, linking Kaysone Phomvihane to Mukdahan in Thailand has encouraged the sprawl of residential and commercial establishments along National Road No. 9 further converting previously unused lands and agricultural areas. With the increased trade and traffic volume, the land use pattern has changed to accommodate the use for residential and commercial purposes. At present, residential and commercial mixed uses account for 64% of urban land use. The mixed use policy is provided for in the master plan of Kaysone Phomvihane. A new friendship bridge built across the historic Mekong River links Kaysone Phomvihane and Mukdahan, Thailand.

The land area of the town district covers 779.03 km2. The urban town is divided into 31 villages. The centre of Kaysone Phomvihane is the old town center built during the colonial period. The town center is characterized by thriving trading and commercial activities including production of goods in Savannahket and trade of goods imported from Thailand and Vietnam. The town center is divided into zones or areas including the old city center with heritage buildings from the French period. Around the old city center is the core business district including banks, shops, hotels and restaurants located along the major city thoroughfare. Along the Mekong River facing Moukdahan, there are also a number of hotels, small restaurants and eateries, and makeshift recreational facilities that were erected during the traditional boat racing festivals. The provincial and district offices of government agencies are mainly located along the Mekong River.

3.2.2 Geology and geotechnical characteristics

Hydrogeological information collected from various sources and the field reconnaissance at the project site and surrounding areas where construction is going on, explain the geological condition of the site.

The geology reconnaissance map of the surrounding area indicates the extended quaternary alluvial/colluvial deposit composed of silty sands and sand. Some study mentioned the massive medium grained sandstone and weathered very fine to grained sandstone are observed along the watercourses.

General geological condition of Savannakhet basin is similar to the Korat basin structure with the central area underlain bay salt formation. This is a formation of sandstone, soft shale and siltstones, with thick beds of rock salt, gypsum and anhydrite. It is believed that the area is of internal drainage with respect to groundwater with sub-surface flow supporting numerous swamps and lakes, which are often the only source of stock water in the area‟s frequent drought periods.

Based on the observation of bank cut and excavation for construction around the area of the project site, the thickness of the topsoil is about 50cm and thicker where flood often occurs. It is mainly composed of fine sand and silt. In general, presence of weathered lateritic soil is suitable for embankment fill.



Underneath the topsoil and down to the depth of bottom Mekong about 15m, there is no presence of sandstone. The soil is composed of coarse sand mixed with silt and clay. Beside the proposed project area there are ponds was a quarries for road materials of lateritic soil mix of gravel and clay depth more than 2-3m.

The Seismology study by JICA for Houay Lamphan Gnai Hydropower Project in Sekong province stated that the central and southern parts of the Lao PDR have very small danger of gigantic earthquake. The severe earthquake zone exists in the Northern part near the China and Myanmar borders. The earthquake acceleration distribution map and seismicity distribution map for seismic design in Lao PDR are presented in the Laotian Electric Power Technical Standard (prescribed by MIH with support from JICA in 2003). The KSP WWT Subproject is located in a minor zone, which is the lowest earthquake risk area in Lao PDR, and the expected earthquake acceleration at the project site is less than 2.5 gal according to Figure 3: with comparing to Orange area 250-80 gal. The structure of works for KSP WWT subproject in our design are small concrete structures. The sewerage pipe lines are from HDPE pipe, the urban drainage structures and drainage canal from the prefabricated concrete products joined on site. Therefore in our design the seismic riskshave been considered as minor.

Figure 3: Seismicity Distribution Map for Seismic Design

Source: JICA Sekong Province. Seismology Study for Houay Lamphan Gnai Hydropower Project.Technical Economic Feasibility Study. 2009

3.2.3 Hydrogeology and climate

Hydrology observation flow of the Mekong at Kaysone Phomvihane has been recorded continuously since 1929 with little interruption. The maximum recorded flood estimated at 49,100 m3/s with the highest water level at about 138,66m above mean sea level (msl) that occurred in 1991. Based on the flood frequency analysis, the 1991 flood corresponds approximately to a 25 year-flood.

Climate and meteorological dataSavannakhet has a tropical climate, south-westerly monsoon winds bringing heavy precipitation from the middle of May to October over the lower Mekong region. From November to the middle of March, the northeast monsoon brings heavy precipitation but less often. During the rainy season the humidity is very high, recorded as high as 92 % at Kaysone rain gauging station in November. This can



result in isolated showers over small areas or, under certain wind conditions, thunder showers over a larger area. The maximum annual rainfall in the project area has observed high precipitation relevant to the catchment area. The mean annual rainfall in the project area varies from 1,070 mm to about 1,982 mm a year. The hottest month of the year is usually April with temperatures up to 32°C, whilst the coldest month is December with temperatures down to 17.1°C.

3.2.4 Planned Development

The updated Kaysone Phomvihane Socio-Economic Development Plan for 2010-2014 has identified key infrastructure development projects for priority investments. These include essential urban infrastructure on water supply and sanitation, road improvement and drainage and flood control, solid waste and wastewater management to support tourism and urban sector development.

In line with the national and provincial strategies for urban development, the town conceived its vision statement based on its development goals and targets. Towards the next decade, the District of Kaysone Phomvihane envisions to be “an attractive and charming city aiming to become the international and regional core city for increased trade and traffic flow of people, goods and services along the East West Economic Corridor in the Greater Mekong Subregion.”

This vision statement was adapted from the series of advisory committee meetings and stakeholder consultations organized by JICA for the preparation of strategies for the development of regional core cities (Preparatory Survey on Formulation of Basic Strategies for Regional Core Cities Development in Lao PDR; January 2010). Subsequently, district authoritiesreferred to this vision statement as basis for the preparation of the urban development strategy and strategic local economic development plan.

The development vision was also presented and discussed during the National Project Inception Workshop held on 10 June 2011 in Kaysone Phomvihane. It served as the essential development framework during SWOT (Strength, Weaknesses, Opportunities and Threat) analysis session that was actively participated in by local authorities, village and cluster leaders and representatives from government agencies and private sector groups.

3.2.5 Existing Land Use and Zoning

The emergence of the town of Kaysone Phomvihane started with the movement of people from the area facing the Mekong River, to the eastern and northern areas of what is now the town center. The completion of the Second Friendship Bridge, linking Kaysone Phomvihane to Mukdahan in Thailand has encouraged the sprawl of residential and commercial establishments along National Road No. 9 further converting previously unused lands and agricultural areas. With the increased trade and traffic volume, the land use pattern has changed to accommodate the use for residential and commercial purposes. At present, residential and commercial mixed uses account for 64% of urban land use. The mixed use policy is provided for in the master plan of the town.

3.2.6 Core Urban Area

The centre of Kaysone Phomvihane is the old town center built during the colonial period. The town center is characterized by thriving trade and commerce activities including production of goods in Savannahket and trade of goods imported from Thailand and Vietnam. The town center is divided into zones or areas including the old city center with heritage buildings from the French period. Around the old city center is the core business district including banks, shops, hotels and restaurants located along the major city thoroughfare. Along the Mekong River, facing Moukdahan, there are also a number of hotels, small restaurants and eateries, and makeshift recreational facilities that were erected during the traditional boat racing festivals. The provincial and district offices of government agencies are mainly located along the Mekong River.



It should be noted that a new city center has been designated along the EWEC, which is envisioned to be the future center of economic activities for the district, given the presence of the Savan-Seno Special Economic Zone. This location is considered ideal for the expanding commercial and business establishments such as supermarkets and shopping malls, restaurants and coffee shops. It would also serve as a new tourism destination in the province.

3.3 Socio- Economic Conditions

3.3.1 Current Economic Activities

The increasing urban population has outpaced the availability of economic opportunities in Kaysone Phomvihane. Under-employment and an intensive informal sector are unfortunate by-products of urbanization. There are employment opportunities in such sectors as manufacturing, construction, transport, services, and tourism which will be created from the growing number of manufacturing industries, and medium and large enterprises that are expected to be located in the Savan-Seno Special Economic Zone (SSEZ).

Given its strategic presence along the transport corridor, Kaysone Phomvihane has emerged as the focal point for development of secondary and tertiary industries that are established in the province of Savannahket. The services and industry sectors are the major source of employment and income for local residents who have the technical skills and educational background. The demands for local skilled and unskilled labor are expected to increase over the next two decades with the continued development and expansion of the SSEZ, the increasing cross border trading between Thailand and Lao PDR with the completion of the Second Mekong Friendship bridge, and the improved road network connectivity along EWEC where Kaysone Phomvihane is strategically situated.

Based on the Gross Domestic Product (GDP) over the last three years, the economy of Kaysone Phomvihane grew from 9.41%in 2006 to 9.75% in 2010. The GDP per capita registered an increase from US$870 in 2007 to US$1,027 in 2010. The economic trend indicated the gradual shift from the agriculture sector which had a share of 20.58% in 2010 to the services sector and industry sector at 46.69% and 32.98% respectively during the same period. The shifts in the economic activities are influenced by the improved trade and traffic flows along the EWEC.

Table 1: GDP in 2006-2009 and Estimate from 2010-2014 Items 06-07 07-08 08-09 09-10 10-11 11-12 12-13 13-14

Gross Domestic Product per person/US$ 712 870 945 1,027 1,116 1,215 1,333 1,464

GPD growth rate (%) 9.41 9.68 9.75 9.82 9.97 10.85 10.89

GDP sharing

-Agriculture-Forestry Sector 20.94 20.93 20.78 20.58 20.33 20.04 19.61 19.17

-Industry-Commerce-Handicraft Sector 30.86 31.23 31.81 32.36 32.98 33.48 34.32 35.15

-Service 48.20 47.84 47.41 47.06 46.69 46.47 46.07 45.68

Source: Government of Lao PDR. Province of Savannakhet. Kaysone Phomvihane Planning Office. Statistic Survey 2009.

Kaysone Phomvihane has 368 factories engaged in various activities such as food processing, garment making, wood processing and furniture making, concrete products and aggregates. Of these factories, 23 small and medium processing plants in 2007 increased



to 36 factories in 2010. The total production output of these factories was valued at 450.33 Billion LAK in 2010. These factories provided employment opportunities to more than 2800 workers. There were a number of factories that closed due to poor quality of products but new factories for bottled water, beer breweries, cigar manufacture and car assembly plants, among others, that are being established to employ local workers.

The agriculture sector, which is still the major economic resource base of Kaysone Phomvihane, accounted for about 20% of the national production since 1990s. In 2009, the rice production area covered 14,681 hectares, registering an increase in area of 4,037 hectare from year 2005. Aside from the cultivation of rice, the growing of rubber trees is becoming an important agricultural activity with about 180 hectares being planted with such trees. The commercial trees are eucalyptus, grown in an area of 105 hectares while Aga wood is planted in an area of about 30 hectares. Livestock and poultry-raising, including animal feeding and fish farming, are being promoted by local authorities as livelihood activities to alleviate poverty in the villages.

The commercial services sector is largely influenced by the three big market trading centres and two smaller public markets in Kaysone Phomvihane, where buyers and sellers trade products, goods and services. These markets are the outlets for local products such as vegetables, meat and processed goods. Market stallholders and ambulant vendors are the key players in the economic trade and commercial services sector in the town. In 2009, there were 3,226 commercial and trading shops generating a reported sale of 9.753 Billion LAK. These commercial establishments employ local labor as service providers for selling and vending. Most of the major consumer products sold in the commercial shops are imported from neighbouring countries like Thailand, Vietnam and China.

The number of hotels, lodging houses and restaurants are increasing to accommodate the growing number of visitors and tourists in Kaysone Phomvihane. These establishments located mostly in the town center are providing local employment to service providers.

3.3.2 Household Occupation and Employment

About 60 percent of household in Kaysone Phomvihane are employed in the services sector which is largely due to the increasing number of trading and commercial activities in the town. Given its agricultural resource base, more than 38% of household are engaged in agricultural activities such as crop farming particularly rice production, livestock and poultry-raising, and fish farming. A small percentage of households are into handicraft making and home-based activities.

Table 2: Household divide into economic sector Number of Household working in Percentage

Agriculture and Forestry 38.26 %

Industry and Handy craft 1.25 %

Commercial and Service 59.98 %

Other 0.51%

Total 100%

Source: Government of Lao PDR. Province of Savannakhet Planning OfficeKaysone Phomvihane.Statistic Survey, 2009

The working age group of 14-60 years old in Kaysone Phomvihane constitute more than 68% of the current labor force. However, this working group has low level of skills and educational attainment to compete for employment in the factories and manufacturing industries. In view of this, industry locators requiring specific skills would employ workers and laborers from other areas and neighbouring countries. The inadequacy of funds to support vocational skills trainings and human resource development programs contributes to the low quality of local labor and manpower resource.



There is a growing trend in the handicraft industry and related commercial activities as a result of the increasing demand for local products and services in the town. The improved trade and traffic flow is a result of the connective transport and road networks,which have stimulated further demands for goods and commodities from the factories, processing plants and small and medium scale manufacturing industries. Kaysone Phomvihane has established its One District One Product (ODOP) program to promote small-medium enterprises such as dry meat products and sausages. Through the ODOP, the town is now producing its famous Lao cotton products, which are being exported to Japan and Europe.

3.3.3 Public Sector Investment

During the last five years, the government has invested considerably in road and transport projects that included the upgrading of 10 major road networks and construction of bridges and the repair and rehabilitation of secondary roads. Investment from the government includes development of the dry port and transportation logistics center near the border gate close to the Second Friendship Bridge.

During 2005-2009, the Kaysone Phomvihane Urban Development Administration Authority (UDAA) has been active in urban road maintenance, drainage and street cleaning, landscaping including tree planting and grass cutting. UDAA was also involved in the installation of street lighting and other street amenities to a total cost of 33.9 Billion LAK.

Major public sector investments in Kaysone Phomvihane went to education and health care sectors as part of the social welfare and development priority programs. The government established 40 kindergarten schools, 71 primary schools, 21 secondary schools and one university. The local residents have access to health care services and facilities through the provincial hospital located in the town center and with the district hospital. To complement the health services are the 13 health care centers, 34 pharmacies and 39 private clinics operating in the district.

3.3.4 Private Sector Investment

Kaysone Phomvihane has three major markets, two small markets and 1,239 shops, which are being managed and operated by the private sector groups. There are two privately managed transport terminals in the town. One bus terminal serves passenger buses and transport facilities travelling through cross country border routes to Cambodia, Thailand and Vietnam. The other transport terminal serves commuters travelling within Savanakhet and neighbouring provinces. The private sector groups are also investing in food processing, agricultural farming and consumer products.

The Savannahket Chamber of Commerce and Industry (SCCI) is an organization of private business groups engaged in various business and industrial activities. Within the SCCI are subgroups that have investments in hotels, lodging houses and restaurant establishments, import and export of consumer products, construction materials and other small and medium scale industries. One member of the SCCI is engaged in solid waste haulage and disposal including the operation of the material recovery facility at the Kaysone Phomvihane dumpsite.

3.4 Eventual Existing plans for WWT

No study and no other relevant projects related to wastewater management have been made previously for the town. No project has been implemented to improve wastewater situation, flood control and wastewater management. Only two flab gates were installed for flood control on Houay Longkong and on Houay Khilamang, but none of these has been functioning. No public wastewater management and sewerage system were implemented.

3.5 Urban and environmental infrastructure

The increasing population in the town center is putting considerable pressure on existing urban infrastructure and support services. In Kaysone Phomvihane, urban



environmental infrastructure is inadequate to meet the current, as well as growing demand of the increasing population. This is particularly evident in the town center.

3.5.1 Water Supply System

The state-owned water supply enterprise, Provincial Nam Papa, operates and manages the water supply and sanitation system in Kaysone Phomvhane. Of the total district population of 118,748 in 2010, Nam Papa supplied potable water to about 75,000, representing 61% of the population. The area served with water covers the six village development clusters of the urban area within the town.

The existing water supply system was established in 1974 and completed in 1977 through financial assistance from the French government. The facilities of the water supply system include the installation of the water treatment plant with a capacity of 15,000 cubic meters per day. The total length of the main transmission and distribution pipelines is 54 km. The water treatment and supply facilities have deteriorated due to limited financial capacity and resources for operation and maintenance.

In 2003, a grant from Japan provided technical and financial assistance to Nam Papa for the rehabilitation of the water intake and water treatment plant facilities. As a result, the water supply system managed to retain its original daily capacity of 15,000 cubic meters. In its efforts to meet the water supply requirements of the increasing number of households in the town center and adjacent areas, Nam Papa executed in 2010 a Memorandum of Understanding (MOU) with a Malaysian private sector group for the expansion of the water supply system and facilities in order to provide an additional capacity of 7,000 cubic meters per day. According to the MOU, the Malaysian investor undertook a feasibility study to provide adequate water supply to the Kaysone Phomvihane district including the requirements of industries, business establishments and locators in the Savan-Seno Special Economic Zone.

3.5.2 Sanitation and Sewerage Treatment

The existing sewerage treatment system in the town involves individual treatment for households and business establishments through the use of pour-flush or dry latrines that are discharged to septic tanks and soak pits. In 2005, approximately 71% of households in Kaysone Phomvihane had access to sanitary toilet facilities. By 2010, this increased to 97%. Wastewater from other uses including ablutions, laundry, and food preparation are discharged directly to the storm water drains without any treatment. There are no installed grease or sediment traps for pre-treatment wastewater coming from either households or business establishments.Manufacturing industries in the SSEZ discharge wastewater directly to the drainage structures through simple treatment via storage tank. The inadequacies of effluent sewage pipes from septic tank have been the cause of sewage leakage,which result in pollution of soil and ground water levels.

In Kaysone Phomvihane, the coverage of septic tank systems is low. The existing septic tanks are poorly designed that result in the overflow of sewage, blocking the open drains with sludge and creating bad odours. At the existing dumping site which is about 12 kms from the town center, there is a space provided for dumping sludge collected from the households. In most cases, a private vacuum company collects the household sludge when the septic tank is full and dumps these into open farm lands or any designated vacant spaces that are convenient for them. There have been complaints aired by the local communities affected by the unsanitary environment.

The Provincial Nam Papa collects fees for wastewater from the households who are connected to the water supply system. The wastewater collection fees are included in the monthly water bills that are charged to the household users based on the water meter reading. Households are charged a flat monthly rate of LAK 2,000 for wastewater collection. Of the monthly collected fee, tNam Papa remits to UDAA, LAK 1,500 and retains LAK 500 as its collection management fee. In 2010, a total of 12,402 households were connected to the water supply. According to the Provincial Nam Papa and UDAA, the collection rate for



wastewater is only about 40%. UDAA acknowledged that the low collection rate is largely due to the poor wastewater management system in the urban areas.

3.5.3 Solid Waste Management

The solid waste management system in Kaysone Phomvihane involves the collection of garbage from residential areas, hauling it to the designated dumpsite. The open dumpsite was established in 1996 and covers an area of approximately 16 hectares (ha). Households pay 11,000 kip per month for garbage collection. Hotels, restaurants and other business establishments are responsible for taking their solid wastes to the dumpsite. Solid wastes are carried to the dumpsite by two garbage trucks where they are dumped into a hole and then spread out by a backhoe. When the hole is full, it is covered by soil or clay.

Of the 16 ha area, only 4 ha is being utilized for the current dumpsite.The UDAA is responsible for solid waste management including the operation and maintenance of the dumpsite. The service area of UDAA‟s solid waste management system covers more than 10,000 households mostly in the town center. With the increasing population, the UDAA is faced with the challenge of both expanding the landfill site and improving the collection system. The existing two garbage trucks are inadequate to serve the requirements of the current and growing population. Within the dumpsite, a private sector company manages a material recovery facility (MRF) where the solid wastes with economic value are segregated and bagged and then sold to business enterprises.

3.5.4 Flood Control and Drainage

The Provincial Department of Public Works and Trasport (PDPWT) is the government agency responsible for the improvement and maintenance of the drainage and flood control measures. The PDPWT coordinates closely with the UDAA in preparation of drainage and flood control plans, project proposals and investment programs.

The existing drainage system in the town center area consists of roadside drains and open channels where flood water flows through natural streams and creeks before finally discharging to the Mekong River. Flooding often occurs in the old town area during high tides on the Mekong River when flood waters cannot be drained. In the low-lying areas, flooding occurs for 2-3 days, adversely affecting the movement of people, goods and services.

The drainage network and flood mitigation system is an old system that was improved during 2000 - 2003 under the ADB-assisted Secondary Towns Development Project (covering Savannakhet and four other areas). The primary, secondary and tertiary drainage channels in the town area were rehabilitated, and the flap gates were installed as the outfall to the Mekong River. At present, there are three large discharge points from the town to the natural canals that eventually flow to the Mekong River. Two of these locations have flap gates to prevent water from the river to flow back to the urban area. These gates have never been operational due to mechanical defects. As a result, flooding occurs during heavy rains when the river is at high water level.

The drainage system for the northern part of the town was constructed under the Secondary Towns Project and it consists of concrete lined open trenches along the Visoukan road and drain direct to Mekong at Chomkeo stream outlet. This is the area where the new Savanxay market and the bus terminal are located. The drainage system cannot cope with flood of surface waters, and it requires considerable improvement to mitigate flooding which affects the roads and business establishments and drain the stagnant of waste liquid and solid around Savanxay Market.

3.5.5 Urban Roads

The PDPWT is also the agency responsible for the road network and transport planning in the Province of Savannakhet. In the town of Kaysone Phomvihane, the UDAA coordinates closely with the District Office of the Public Works and Transport (DOPWT) for the planning, operation and maintenance of urban roads.



The JICA study indicated a total road network of 192.5 km withintown. The main urban roads have a total length of 55 kms of paved roads and 10.5 km of unpaved roads. The minor paved roads in the interior urban areas have a total length of 46.6 kilometers and while the unpaved roads measure 77.4 kilometers. In addition, nearly 3 kms of access roads and footpaths were constructed under a Japanese grant between the intersection of National Road 9 and the Second Friendship Bridge. Most of the urban roads within old town are being repaired and maintained. However, due to inadequate drainage network, several of the urban interior roadsare in the state of deterioration and are annually damaged by flooding events during the rainy season.

3.6 Consultations and Surveys

A series of consultative meetings and field discussions were conducted in Kaysone Phomvihane and at the provincial level to generate the perception and views of the project stakeholders on the preparation and design of the Kaysone Phomvihane Wastewater Treatment subproject. In these sessions, the major topics that were discussed with the EA and local authorities in relation to the proposed subproject were:

i) determination of the priority drainage networks for improvement and rehabilitation;

ii) technical considerations on the design of the open storm water drains and sewage pipelines to be embedded in the storm drains;

iii) design considerations for the installation of the new wastewater treatments in three strategic locations;

iv) preliminary design features, layout and cross sections of the storm drains and sewage pipelines;

v) indicative cost estimates of civil works and related structures and facilities; vi) social, environmental and resettlement concerns and impact; and vii) operation and maintenance arrangements between PDPWT and UDAA.

As basis for planning and design consideration, the existing 1: 100,000 topographic map was used, including existing maps from the PDPWT and UDAA. Site visits and field investigation were carried out to validate the preliminary design and technical drawings. Technical discussions with the Engineers and officials of Provincial Government, PDPWT and UDAA including dialogues with key informants provided valuable data and relevant information on conditions of the drainage canals and sewage pipes including the proposed sites for the installation of the wastewater treatments.

References were taken from the technical documents and reports of the ADB-funded Secondary Towns Development Project, particularly those related to the construction of the open drainage canals at the northern, central and southern sides of the town. From these documents, the technical information of elevation and alignment of the drainage networks were derived and have served as useful basis for undertaking the preliminary design and technical drawings.

A site reconnaissance survey was undertaken in the three potential project sites for drainage structures and wastewater systems in Kaysone Phomvihane:

At the southern part of the town, open canals were constructed under the ADB Secondary Towns Development Project. The 2 km long canal was intended to drain the storm water during the rainy season. The canal structuresare still in good condition with only minor spots found to be damaged. The last 0.5 km section of Houay Longkong stream has no drainage structure and this section gets flooded when the water level at the Mekong River rises. There is no existing wastewater drainage system in the area. For Kaysone Phomvihane town,the topographical map with the scale of 1:5,000 was obtained as reference material. To complement the technical analysis, additional survey was undertaken using GPS to spot check existing canal alignment and the specific sites for the construction of drainage network for wastewater collection and disposal.



At the central drainage system around the Savanxay Market, drainage structures

were installed on the western side of the market and bus terminal with open concrete channel leading to the Chamkeo stream, and draining to the Mekong River. There are no drainage structures on the eastern side of the market and the wastewater generated from the market are drained on the roadsides.In the preparation of the subproject feasibility study, additional survey was undertaken using GPS for spot checking the alignments of the drainage structures to the Chomkeo stream and to the Mekong River.

In the northern portion of the town, open canals were constructed under the ADB

Secondary Towns Development Project. Presently, wastewater from households and business establishments are disposed to the open canals and drained to the natural stream and creeks without proper treatment. With the growing urban population and increasing number of commercial establishments, the open canals have become inadequate for wastewater collection and disposal. This causes contamination of the local environment, particularly during the rainy season when the sludge and effluents from wastewater overflow in the open canals.The sites for the improvement of the storm drain canals and the establishment of the wastewater treatment plants were validated and measured in terms of different elevation from the point where wastewater will be collected and treated. The sites for the installation of sewage pipelines along the existing storm drains and potential areas were also inspected.

3.7 Institutional Arrangements

In Kaysone Phomvihane, the urban sector development is the responsibility of the UDAA. It was created initially for the management and implementation of the ADB-assisted urban development and infrastructure project. This was part of the provision of the ADB loan to the Government of Lao PDR (Loan No. 1525) for the Secondary Towns Urban Development and the grant assistance (TA No. 2972) for support to UDAA. The UDAA has a status equivalent to a division within a provincial administration. It was established to be a financially independent authority, which is able to generate its own revenues. Under its mandate, it may use internally generated revenues for its urban infrastructure for urban development and administration.

The UDAA coordinates with PDPWT and DOPWTfor the preparation of development and investment programs for urban infrastructure, including institutional arrangements for the implementation of priority urban environment infrastructure. In the case of the Kaysone Phomvihane Wastewater Treatment subproject, the overall management responsibility will be lodged with the Project Management Unit (PMU) to be established by MPWT, which is the designated Executing Agency of the Project. A Project Implementation Team (PIT) will be organized, which will managed by UDAA in close collaboration with the DOPWT.

The UDAA is in charge of the management, operation and maintenance of the wastewater management system. It coordinates with the Provincial Nam Papa, which is in charge of collecting the wastewater fees. Of the LAK 2,000 monthly fee collected from the households, Provincial Nam Papa retains LAK 500 as its management fee and remits LAK 1,500 to UDAA to defray the expenses for the operation and maintenance of the wastewater management. However, the collection rate has been very low as most residents are passive in paying the wastewater fees because of what they perceive as inadequate services.

Given the limited operation and maintenance budget, UDAA coordinates with the Provincial Government of Savannahket and the PDPWT for supplementary funding support. UDAA gets its regular budget for operation and maintenance from the District Authority of the Kaysone Phomvihane. Currently, DOPWT and UDAA undertake joint activities for the



repair and maintenance of interior roads and drainage structures, and conduct meeting with the PDPWT and the Provincial Government of Savannahket.



4 POPULATION GROWTH & DEMAND FORECASTS

4.1 Design Horizons

The design horizon for wastewater from households and industry is 20 years, from 2015 to 2035. However, to comply with climate changes with respect to the storm water systems, the design of flood protection systems should be based on a 50 year period of return.

The design capacity requirement for the pipe line sewerage is based on the service areas and their assumption of the development and the provisional conceptual land use plan and population zoning and density. The carrying capacity of storm water drains, the sewerage pipelines and the wastewater treatment is designed to be effectively functional for a period of 20 years.

The design for drainage canal capacity and the pumping capacity is based on the hydrology and the catchment area to estimate run-off. The design of the last section canal on Houay Longkong, pumping discharge capacity and the existing box culverts shall be used in computing the flow, thus the “Rational Method“, in either the 10, 20 or 50 year rainfall frequency.

4.2 Population and Demand Forecasts

The 2010 population records for Kaysone Phomvihane accounted for 76,905 inhabitants and 12,252 households. As the capital town of Savannahket province, Kaysone Phomvihane has a relatively high population density of 75 persons per hectare as compared with the district wide population density of 17 persons. The concentration of the urban population is along the three main urban areas of the Kaysone Phomvihane, Santhiphap and FaNgum roads. The urban population is characterized by multi-strata economic classes with large proportion of immigrants from neighbouring countries such as Vietnam, Thailand and China.

The reported annual population growth rate of 2% and the increase in the traffic volumes are putting considerable pressure on the part of provincial and local authorities to meet the demand for improved and widened urban road networks within the town center. The population figure will dramatically change with the growing number of industry locators in the Special Economic Zone and its economic spill over effects on stimulating the growth of the business sector. By 2030, the town‟s population is expected to increase to129,136 inhabitants and the volume of traffic flow is anticipated to double in number. More than 80% of the town‟s urban population will benefit from the improvement and rehabilitation of the storm water drainage and sewage networks and installation of new wastewater treatments under the Kaysone Phomvihane Wastewater Treatment subproject.

The subproject will also contribute to the further increase in economic activities, with the anticipated growth in number of private sectors in commercial and business ventures due to improved access and excellent conditions of the major urban road networks.

Table 3: Population Projection 2015-2030, Kaysone Phomvihane

Source: Government of Lao PDR. Province of Savannakhet. Kaysone Phomvihane Socio-economic Profile, 2010

Kaysone Phomvihane

Annual

Growth Rate

2010 2015 2020 2025 2030 %

31 villages 76,905 95,950 93,747 116,963 129,136 2.0%



4.2.1 Migration Patterns

The 2005 Census recorded the 9,469 people moving out of Savannahket for a number of reasons including limited economic opportunities in the province. However, there was also immigration of about 5,500 people in response to the opening of the transport corridors. The JICA study projected increase in the population in both the district and town of Kaysone Phomvihane.This is due to the increasing number of business enterprises and locators being developed in Savannakhet‟s Agro-industrial Zone, outside of the town where the Savan-SENO Special Economic Zone is located.

Figure4. Population zoning and density for next decade of Kaysone Phomvihane




4.2.2 Population forecast for projected service areas

Wastewater generation within the service areas(drainage/catchment areas) has been determined on the basis of the studied land use and population within the urban boundaries shown on conceptual land use plan Figure 4.

Table 4: Population forecasted of projected services area

Source: Government of Lao PDR. Province of Savannakhet. Statistical Yearbook 2009

4.3 Demand-Supply gap analysis

The existing storm drainage system of the southern part of Kaysone Phomvihane was constructed mainly to drain the runoff from the catchment area. The system is in good condition and is functioning. Thus, there is a need of maintenance and monitoring the side drainages from households and factories and intersecting roads,so as not to cause an erosion of canal slopes and eventual damage to the main canal. The project will only improve the minor damages to the previous constructed standard.

During dry season, the drainage canalsmainly transport wastewater directly to the stream without any pre-treatment.Under this project,the generated wastewater shall be intercepted from the bottom of existing storm water drainage or combined sewers and conveyed to a wastewater treatment through the pipe line. The wastewater pipe line shall be installed at the bottom of canal. The size of pipe line and wastewater treatment was estimated for a 10 year-period for this subproject. However the wastewater or sewerage pipe of the sections embedded underground should reach for 20 years. The existing canal has been designed to carry storm water with the trapezoidal canal form. The size of the last section has a bottom width of 3.0m, the side slope 1:1.5 of about 2m in height. The canal has been operating for nearly ten years now. The high water level at the last section of the canal is being flooded back by water from Mekong river. The existing drainage canal needs to do reconstruction or modification. It will keep the canal to continue service as there is no additional diversion to the catchment area.Only minor changes inthe surface pavement and it will reach the run off faster.

The last section of drainage canal has a bottom width of 4.0m, side slope of 1:2, and is about 4.0m in height, with riprap erosion protection. The relevant parameter for the design considerations areslope stability, requirement of minimum and maximum flow velocities, need for a big volume of reservoir, and flood condition.

The drainage pump station for flood control is recommended for this project. The flood occurs at the same time of the year when the water level is high at Mekong and high run off on the catchment. The pumping capacity was determined from the estimation of 24 hour maximum precipitation (1975-2009) for station Savannakhet Province, 10 years return frequency.

The design of drainage around the Savanxay Market adopted the side drainage urban road which included pipes culverts D1,000mm, manholes, gutters and chamber, etc. The southern side drainage of Visukan road was constructed with concrete channel and

Services area Area (ha) Population projected Years Estimated growth rates 2010 2015 2020 2025 2030

Kaysone 31 villages are within the core corridor town

1,340 76,905 95,950 93,747 116,963 129,136 2.0%

Houay Longkong drainage system (southern part)

538 32,000 39,008 43,668 47,550 52,499 2.0%

Chomkeo Stream around Savanxay Market (Central)

81 7,177 7,923 8,748 9,659 10,664 2.0%

Houay Khilamang drainage system (northern part)

500 25,602 30,475 33,647 37,149 41,015 2.0%



inU-form. The wastewatersewage pipeline from the southern of Visukan road will be installed along with the new drainage structures around the Savanxay Market crossing the Chomkeo road. This will discharge the wastewater to the Chomkeo stream and will be drained to the Mekong River after treatment. The catchment area of the wastewater collection and treatment covers 81 ha with a projected population of 8,750 in year 2020. Due to the available land,a septic tank filter will be installed to serve as the wastewater treatment facility.

The design of the wastewater treatment facility in the northern side will take into consideration the increasing number of economic activities, caused by the growing number of commercial establishments and residential houses. The size of sewer pipelines that will be embedded underground will be designed for 20 years horizon. The design of the wastewater treatment facility will allow for an operational lifespan of more than 10 years. The catchment area of the wastewater treatment in this northern side covers 500 hectares with a projected population of 33,647 in year 2020.

Presently, Kaysone Phomvihane has severe problems associated with unsanitary environment caused by the inadequacy of essential urban infrastructure, wastewater collection and treatment system. The sewage is flowing openly in the canals in the inner town and being discharged without proper treatment. The threat of seasonal severe pollution of the local environment will adversely affect the socio-economic conditions and health situation in the town. Local residents, specifically the poor and other vulnerable groups, are exposed to health hazards associated with poor environmental sanitation, through water-borne illnesses, loss of income and economic opportunities. With continued growth of the urban population of the town, unsanitary environment condition will become severe that it will adversely impact the socio-economic condition of the urban center. Such a situation is putting considerable pressure on the part of the provincial and district local authorities to improve the drainage networks and sewage pipelines, and establish the appropriate wastewater treatment plants.

The installation of sewage pipelines and reconstruction of urban drainage system to intercept the storm water and bring it into the main drainage canal will have two outcomes. During the wet season, the system will adequately transport storm water and diluted wastewater away from the populated areas to Mekong River. In the dry season, the system will lead to the wastewater drains in closed sewage pipes to the treatment plants and then discharge after adequate treatment. This will have a substantial positive impact on the urban environment and health situation of the urban residents and will contribute making Kaysone Phomvihane an attractive and competitive town for increased trade and investments.



5 TECHNICAL SOLUTIONS

5.1 Standards, guidelines and formal requirements

The technical designs and parameters for the Kaysone Phomvihane Wastewater Treatment subproject will be based on national and international standards, guidelines and regulations. The technical solutions will draw lessons learned from the experience of the PDPWT and UDAA in undertaking urban infrastructure in Kaysone Phomvihane. This will be supplemented by the conduct of technical surveys and analysis of secondary and primary data and information.

5.1.1 National laws/regulations for Water environment:

a. National Strategy on Environment

The National Strategy on Environment and its action plan for the years 2006-2020 was prepared with the assistance of the Swedish International Development Agency (SIDA). This strategy has the following objectives: to implement measure for sustainable development, to secure sustainable use equitable access to water resource, to use land with securing ecosystem and promote environmental and social impact assessment.

b. Environmental Protection Law (EPL)

The basic environmental law of Lao PDR is the Environmental Protection Law (EPL),which was established in 1999. It stipulates the framework of environment management and the responsibilities of related organizations, of which central one is STEA (restructured to WREA in 2007). It specified necessary principles, rules and measures for managing, monitoring, restoring, and protecting the environment in order to protect public, natural resources and biodiversity, and to ensure the sustainable socio-economic development of Lao PDR.

c. Regulation on the wastewater discharge from industrial processing

factories

This is a regulation of the minister of Industry and Handicraft (it is presently the Ministry of Industry and Commerce) issued in 2005.

If a factory environmental inspector finds a factory discharge any wastewater or other waste into any public area whichhas harmful effects on ecology and people‟s health, living things or any properties, he/she will cancel certification of wastewater discharge from the factory and notify the factory‟s owner. The director of Industry Department of the Ministry or Province can suspend or terminate factories that violate this regulation until the improvement of wastewater treatment system complies with standards.

d. Water Supply Law

The Water Supply Law was approved by the National Assembly in November 2009. But almost all the stipulations in the Law are the water supply services. Sanitation and sewrage matters are planned to be stipulated by degrees which will be prepared from now on. As the law was approved, the revision work of Water Resources Law was started by WREA with the assistance of ADB. The final draft of the framework for the new water resources policy was already reported in May 2009.



e. Water Quality Standards

Existing water quality standards include those for drinking water, surface water, and underground water. In addition, detailed wastewater standard is set as one of the effluent standards in Lao PDR.

The revised1999 water quality standards for the environmental parameters in Lao PDR, covered not onlywater quality standards, but also air and noise quality. The National Consultation Workshop was held in April 2009 participated in by 170 representatives from different agencies and sector groups that deliberated on the water quality standards.Relevant to surface water standard, the national government agreed to follow the same standards adopted by the Mekong River Commission (MRC) for the GMS countries.

Authorized Surface Water Quality Standard is shown in the following tables. Since such standard has not been stipulated so far in Lao PDR, it is newly provided.

Table 5: Authorized Surface Water Quality Standard

6 No.

7 Substances

8 Symbol

9 Unit

10 Standard Value

11 Method of

Measuremen

t

1 Colour, Odour & Taste - - N -

2 Temperature t OC N‟ Themometer

3 Potential of Hydrogen pH - 5-9 Electronic pH Meter

4 Dissolved Okygen DO mg/l 6 Azide Modification

5 COD

COD ml/l 5 Potassium permanganate

6 BOD5

BOD5 mg/l 1,5 Azide Modification at 20 degree C,5 days

7 Total Coliform

Bacteria

Coliform Bacteria

MPN/100ml 5000 Multiple Tube Fermentation 8 Faecal Coliform Faecal

Coliform MPN/100ml 1000

9 Nitrate-Nitrogen

NO3-N mg/l <5.0 Cadmium Reduction

10 Ammonia-Nitrogen

NH3-N mg/l 0.2 Distillation Nesslerization



11 Phenols

C6H3-OH mg/l 0.005 Distillation Nesslerization

12 Copper Cu mg/l 0.1 Atomic Absorption Direct Aspiration

13 Nickel Ni mg/l 0.1

14 Manganese Mn mg/l 1.0

15 Zinc Zn mg/l 1.0

16 Cadmium Cd mg/l 0.005

17 Chromium, Hexavalent

Cr6+ mg/l 0.05

18 Lead Pb mg/l 0.05

19 Mercury

Hg mg/l 0.002 Atomic Absorption Cold Vapour

20 Arsenic

As mg/l 0.01 Atomic Absorption Direct Aspiration

21 Cyanide CN- mg/l 0.005 Pyridine-Barbituric

22 Alpha-Radioactive α Becquere l/l 0.1 Counting machine 23 Beta-Radioactive ß Becquere l/l 1.0

24 Total Organo chlorine - mg/l 0.05 Gas Chromatography

25 DDT C14H9Cl5 mg/l 1.0

26 Alpha-BHC αBHC mg/l 0.02

27 Dieldrin C12H8Cl6O mg/l 0.1

28 Aldrin - mg/l 0.1

29 Heptachlor and Heptachlor Epoxide

- mg/l 0.2

30 Endrin - mg/l None

Source: Government of Lao PDR. WREA. The Agreement of National Standards of Environment in Laos, 2009.

Table 6: Authorized Standards forWastewater Discharge in Urban Area in Lao PDR



Source: Government of Lao PDR. WREA.The Agreement on National Environment Standards in Laos, 2009.

These standards were discussed during the consultative meetings with the representatives of the MPWT, PDPWT and UDAA in relation to the technical design and parameters for the Kaysone Phomvihane Wastewater Treatment subproject. The representative of MPWT indicated that authorized standards for wastewater discharged were adapted in the Vientiane Wastewater Management study and that such standards will also be applicable to the Kaysone Phomvihane Wastewater Treatment subproject.



Table 7: Permissible Values for Wastewater Discharge in urban area in Lao PDR

Source: Government of Lao PDR. WREA. The Agreement on National Environment Standards in Laos,2009. A= Very large sources - to E= Very small sources - see next table



Table 8: Building/Wastewater Source Categorization

Source: Government of Lao PDR. Office of the Prime Minister. National Environmental Standards in Lao PDR. 2009.

11.1.1 International Guidelines and formal requirements

In the preparation of the Kaysone Phomvihane Wastewater Treatment subproject, the following guidelines and formal requirements were taken into consideration:

Principles of Design and Operations of Wastewater Treatment Pond Systems for Plant Operators, Engineers,and Managers, USEPA United State Environmental Protection Agency, August 2011.

Urban Drainage Design Manual, Hydraulic Engineering Circular No.22 Third Edition, U.S Department of Transportation, Federal Highway Administration, September 2009.

Sanitary Sewer Collection, Environmental and Engineering Services Department, the corporation of the City of London, Updated: December 2005.

Standard ATV A210E Principles for dimensioning, Construction and Operation of Wastewater Lagoons for Communal wastewater, October 1989, Germany.

11.1.2 Civil work Standards

Unless expressly stipulated in the Contract of Services, the provisions of the latest revised edition of relevant standards and codes in terms of works to be performed,

No Building Type Criteria Category

1 Suite (Apartment, Condominium)

<100 rooms

101-500 rooms

500 rooms<

D

C

B

2 Hotel, Guest House

<60 rooms

61-200 rooms

201 rooms<

D

C

B

3 Domitory

10-50 rooms

51-250 rooms 251

rooms<

C

D

B

4 Hospital, Clinic

No service

1-10 beds

30 beds<

C

B

A

5 Building for living (village), temple 5,000-10,000 m2

10,001 m2<

E

D

6Disco, Fitness center, Swimming

Pool, Sport center

1,000-5,000 m2

5,001 m2<

B

D

7School, Educational Institute,

College, University

5,000-25,000 m2

25,001 m2<

B

A

8

Office (Government, Private,

International, Private Company,

Theater

5,000-10,000 m2

10,001-55,000m2

55,001 m2<

C

B

A

9 Shopping Center, Super market 5,000-25,000 m2

25,001 m2 <

B

A

10 Market

500-1,000 m2

1,001-1,500m2

1,501-2,500m2

2,501 m2<

D

C

B

A

11 Restorant

< 100 m2

500-1,000 m2

1,001-1,500m2

1,501-2,500m2

2,501 m2<

E

D

C

B

A

12 Service Center (Motor bike, car)

500-1,000 m2

1,001-1,500m2

1,501-2,500m2

2,501 m2<

D

C

B

A

13 Transport Station, Airport

5,000-10,000 m2

10,001-55,000m2

55,001 m2<

C

B

A

14 Slaughter House in the Urban Area

500-1,000 m2

1,001-1,500m2

1,501-2,500m2

2,501 m2<

D

C

B

A

Source:

Building usage

The agreement on National Environmental Standards in Lao PDR,

December 7, 2009, Prime Minister Office and WREA in Lao PDR



materials and equipment to be used, will apply in undertaking civil works for the Kaysone Phomvihane Wastewater Treatment subproject.

Wherever the following acronyms are used, they shall have the following meanings:

ASTM - American Society of Testing and Materials AASHTO - American Association of State Highway & Transportation Officials AWWA - American Water Works Association BS - British Standards Institution ISO - International Organization for Standardization IEC - International Electrical Committee

11.2 Surveys and Technical ReferenceMaterials

11.2.1 Surveys and investigations carried out

The Kaysone Phomvihane Strategic Local Economic Development Plan prepared by the UDAA with the assistance of the PDPWT and the PPTA team provides secondary data and information on the socio-economic conditions and the infrastructure development situation. The number of population and their distribution on the land use map will be the main component for the subproject planning, study for determining of project capacity.

The PPTA had the opportunity to observe the floodingevent in Kaysone Phomvihane during the months of August and October 2011 and made analysis on the recorded flood level data from the UDAA and PDPWT. The valuable data and information served as among the essential reference in the preparation of the design for drainage networks and sewage pipelines and the establishment of wastewater treatment plants in the identified subproject sites..

In the preparation of the subproject feasibility study, the PPTA team referred to the topographical map scale of 1:5,000 with 1m interval contour line. At this scale, the team was able to determine the appropriate planning and alignment of the drainage networks and sewage pipelines and the proper position of the wastewater treatment facilities that would allow enough hydraulic head and water flowing to the intended direction.

The PPTA team engaged the services of a surveyor to determine the accurate position and elevation of the structures and facilities up to 10-15 cm through the aid of the GPS instrument.Additional measurements by GPS were carried out in the specific subproject sites and the results were matched with topographic map at a scale of 1:5,000.

For the southern part of drainage system, the measurement was taken along the existing alignment of storm drainage canals. This was the area planned for the construction of new drainage canal, wastewater treatment plant and culvert outlet for new drainage pumping house.The result of the measurement has shown that the elevation of the sides upper end of existing drainage canal at crossing road is around 135.15MSL, the top culvert crossing Phokadouath is about 131.5MSL, and the bottom of new drainage canal is about 129.0MSL. The designated site for the construction of wastewater treatment plant is about 130.5 MSL to 131.0MSL some higher (bottom stream is 126.50MSL to 127.75). The bottom of existing culvert is estimated to be about 124.00MSL. At this point, there is still water.

For the central drainage system around the Savanxay Market area, spot checks were made along the proposed drainage alignment and the outlet planned for construction of the wastewater interceptor and treatment plant of Chomkeo stream. The result of the measurement has shown that the elevation of the bottom of existing drainage is around 133.5-134.0 MSL.At this point, there will be no problem in draining down the wastewater from the market area.

The northern drainage system was also spot checkedand the results indicated that the proposed elevation of interceptor pipe/intake is 132.4MSL (top canal about 135.0MSL).



Measurement of the proposed area for construction of wastewater treatment plant is about 132.5 MSL (bottom stream is 130.00MSL).

Investigation for the supply of construction materials for the construction work of the subproject is an issue.There are local supplies available including cement, reinforcement bars, concrete aggregates from the river sand and gravel. The lateritic soil for embankment fill can be selected from the borrow area within some distance or the excavated soil can be selected as fill material. Crushed rock is unavailable if the project requires limestone rock. This will be imported from Khammouane province. If the project will consider sandstone rock, it can be canvassed from neighboring towns. The prices of the concrete pipes for drainage culverts from Pakse has been obtained from suppliers.They have competitive prices and the decision will also be based on the quality of their product.

The imported materials were investigated with the agencies in Kaysone and Vientiane for supplying geotextile and the DHPE pipes diameter from D100mm to 600mm supplied from Thailand and Vietnam. The price for final installation has been added 40% to the price of the supplier upon delivery at the site.

The project price estimated include the local and imported materials, transport, handling, labour, profits but is assumedto be without the import tax.

No sampling on wastewater quality control analysis has been available for Kaysone Phomvihane urban area. For baseline data of the project study, three sampleswere taken at three drainage systems and sent to Vientiane for analysis. Results of laboratory analysis are presented in Annex 1. It is concluded that the pollution content of the discharge is moderate to low.

11.2.2 Available material and maps

The UDAA and PDPWT have provided the Urban Environmental Infrastructures and road network map of Kaysone Phomvihane town as base reference for further assessment and analysis of the town‟s drainage networks and sewage pipelines including the key concerns associated with the improvement of the wastewater management and treatment.

For the study of the Kaysone Phomvihane drainage system, wastewater treatment plant and flood control are important to have a location‟s data, the terrain and map of the study areas. The subproject Feasibility Study is using a topographical map scale of 1:5,000 with 1m interval contour line covering Kaysone Phomvihane Urban area obtained from the National Topographical Department. However, the terrain of the subproject areas is flat.To ensure the subprojects planning of drainage systems and wastewater treatment plant have enough hydraulic head and water flowing to the intended direction, a surveyor was hired and the DGPS equipment was used with accuracy in position and elevation upto 10-15cm.

No data and drawing of the existing structures are available for this study. Exact dimensions of existing culverts or other structures to be rehabilitated and reconstructed will be measured for the details design phase.

11.3 Dimensioning - design criteria

11.3.1 Physical conditions

Rainfall

There is a meteorological station at the study area which observes daily rainfall. The station located at Savannakhet (Airport) Latitude:16° 33' 08" , North Longitude: 104 ° 45' 16" East, Altitude :144.099 m.

Table 9 shows the location of station, observation periods and the average meteorological data of the Savannakhet's meteorological gauging station. Figures 5 and 6 show the distribution of monthly rainfall and meteorological data observed for period of 34 years from 1975 to 2009 of Savannakhet meteorological gauging station.

Table 9: Basic Statistic of the Savannakhet's meteorological data



The meteorological station locating at Savannakhet Airport Latitude: 16° 33' 08" North Longitude : 104 ° 45' 16" East, Altitude : 144.099 m

Source: Government of Lao PDR. Province of Savannakhet. Meteorological Station. 2010.

Figure5. Distribution of Monthly Rainfall of Savannakhet Meteorological gauging Station


The hydrology observation flow of the Mekong at Kaysone Phomvihane has been recorded continuously since 1929 with little interruption. The maximum recorded flood estimated at 49,100 m3/s with the highest water level at about 138,66m above mean sea level(msl) that occurred in 1991. Based on the flood frequency analysis, the 1991 flood corresponds approximately to a 25 year-flood.

As to climate and meteorological data,Savannakhet has a tropical climate. South-westerly monsoon winds bring heavy precipitation from the middle of May to October over the lower Mekong region. From November to the middle of March, the northeast monsoon brings heavy precipitation but less often. During the rainy season the humidity is very high, recorded as high as 92% at Kaysone rain gauging station in November. This can result in isolated showers over small areas or under certain wind conditions, thunder showers over a larger area. The maximum annual rainfall in the project area has observed high precipitation relevant to the catchment area. The mean annual rainfall in the project area varies from 1,070 mm to about 1,982 mm a year. The hottest month of the year is usually April with temperatures of up to 32° C, whilst the coldest month is December with temperatures down to 17.1°C.

Figure 6: Meteorological Data Observation of Savannakhet Meteorological Gauging Station

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Total Mean

3.2 17.6 39.7 81.2 197.3 245.4 238.8 327.7 218.9 88.2 9.3 2.8 1470.2 122.5

Max rain fall 1975-2009 36.6 108.1 114.3 286 403.3 447.5 595.4 565.1 545.4 316.3 49.9 33.8 198.2 165.2

Min rain fall 1975-2009 0 0 0 4.9 43.1 83.3 67.4 104.6 43.4 0 0 0 1070.4 89.2

Aver. Evap 1975-2009 121 112.5 150.8 130.9 102.0 76.6 71.5 60.9 62.4 92.3 122.1 126.7 1219.1 102.4

Aver. Humidity1975-2009 69.4 69.0 67.0 69.1 76.1 78.8 77.5 83.7 81.9 77.1 73.5 70.4 893.5 74.4

Aver. Temper 1975-2009 21.4 24.1 25.6 27.7 28.4 27.8 27 27.3 27.3 25.9 23.6 21.6 306.7 25.6

Month

Average rain fall




Runoff analysis of short duration of high rainfall intensity

It is important to evaluate the capacity of drainage system the result of the runoff analysis of short duration of high rainfall intensity as shown in Figure 7:

Figure 7: Runoff Analysis of Short Duration High Rainfall Intensity


Storm Runoff Analysis

Aver. Evap 1975-2009

Aver. Humidity 1975-2009

Aver. Temper 1975-2009

Average monthly evaporation in mm

Average monthly temperatures in °C.

15 ' 30' 45' 60' 90' 120' 180'

Tr = 5 57.16 40.41 33.00 28.58 23.33 20.21 16.50

Tr =10 69.13 48.88 39.91 34.57 28.22 24.44 19.96

Tr =25 84.29 59.60 48.66 42.14 34.41 29.80 24.33

Tr = 50 95.53 67.55 55.15 47.76 39.00 33.77 27.58

Tr = 100 106.69 75.44 61.60 53.34 43.55 37.72 30.80

Rai

n M

ax 2

4 h

ou

rs

24 hours duration maximum rainfall at Savannakhet station analysis



In order to evaluate stormwater levels of drainage system in Houay Longkon area in Kaysone Phomvihane town, the runoff analysis was conducted by adoptinga rational formula which was more suitable for a small sub-catchment area.

To evaluate the design of last section canal on Houay Longkong, pumping discharge capacity and existing box culverts shall be used the “Rational Method“ to compute the water flow in either the 10, 20 or 50 year rainfall frequency. The requirement for adoption depends on the consequences of losses if the project is damaged or not operating.

The design of box and pipe culverts, drainage canal shall be computed by the water flow using the “Rational Method“ in either the 10, 20 or 50 year rainfall frequency. For the requirements given in the Road Standard, the capacity of box and pipe culverts, drainage canal shall be designed for a 10-year return of rainfall intensities, including an allowance for blockage of 20% of culvert area and for free surface non-pressurised flow and discharge velocities of not more than 2.5 m/s.

The “Rational Method” uses the following equation:

Q = 0.278 x C x A x i where: Q = peak flow in cubic metres per second (m3/s) C = runoff coefficient (1.0 for hilly terrain - slopes > 10 %, 0.5 for

rolling terrain - slopes 5 – 10 %, and 0.3 for flat terrain – slopes < 5 %)

i = rainfall intensity in millimetres per hour (mm/hour) for the duration corresponding to the time of concentration for each catchment area

A = catchment size in square kilometres (km2)

Rainfall intensities to be used for the design of culverts, drainage canal for various times of concentration are given from the data rainfall intensity analyses from Savannaket Meteorological gauging station records. The time of concentration for each catchment shall be the time used to select the applicable rainfall intensity. It shall be calculated using the formula given in the Lao Road Design Manual, as given below:

Tc = (0.87 x L3/H) 0.385

Where:

Tc = Time of concentration (minutes) L = Length of stream/river (km) H = Differential elevation along the stream (m)

11.3.2 Dimensioning criteria

Wastewater Management

Contributing areas in the Houay Longkong drainage system are concentrated in the central part of the town. To alleviate the pollution in the most populated town and minimize the effect of addition wastewater flow, the sewerage system developed under this project is the conceptual wastewater flow pattern proposed for the southern portion of Kaysone Town. The contributing area to the initial sewerage system improvements is, therefore, limited to its catchment area. All sewage directly drains to the open canal including intersecting storm drainages of intersection roads and households sewage. It is difficult and expensive to connect all household sewages and intersecting storm drainages to the possible established main sewerage pipe, therefore, the realistic solution is to intercept the sewage on the bottom storm drainages by the sections where intersecting road and take the sewage to the wastewater treatment plant through the pipe line. The pipe dimension will be increased to increase its catchment.



Low Flows Analysis

It is assumed that the domestic wastewater discharge from each sub-catchment, estimated by population, is considered one of major flow components in low flow since domestic wastewater is the dominant water source during dry seasons. Domestic wastewater discharge could be calculated using the following formula.

Di = 0.8pi x wc÷ (1,000)

Where, Di : domestic discharge (m3/d), pi: population in sub-catchment, wc: water consumption per day (l/person) here 180l.

Based on the below referenced water consumption figures and a return rate of 80% for Households/domestic and commercial population, the average total wastewater flow generation rates are summarized in Table 10: Biochemical oxygen demand (BOD5)

Under dry weather conditions, the generated wastewater will be intercepted from the existing storm water drainagethe sewers will convey to a wastewater treatment plant.

Table 10: Average Daily Wastewater Generation


11.4 Technical analysis - Options and feasibility assessment

11.4.1 Project Components

Based on technical evaluation and analysis, the following elements will comprise the components of Kaysone Phomvihane Wastewater Treatment subproject:

Improvementof the southern portion of Kaysone Phomvihane drainage system by constructing interceptor sewer and install pipe to convey wastewater to the treatment plant, construct the drainage channel of last section of Houay Longkong natural stream and build the wastewater treatment plant;

Construction of appropriate wastewater treatment plans;

Installation of drainage pumping station to mitigate flood situation at Houay Longkong drainage system;

Improvement of the central drainage system around the Savanxay Market area by constructing urban drainage and build the wastewater treatment plant applying the septic tank for wastewater treatment plant has considered in according to the land availability; and

Plan preparation for the construction of interceptor sewer to take care of the expanding industrial and commercial area, main wastewater pipe line to convey the wastewater to building up the wastewater treatment plant. This will be connected to a drainage network that drains to a 20 ha area adjacent to the northern Savanxay Market.

Year

Average daily waste water generation, rate (m

3/d)

Average organic loading, rate Kg BOD5/d)

Service Population(persons)

Southern Central Northern Southern Central Northern Southern Central Northern

2005 4608 936 3600 1,468 238 1,147 32000 6500 25000

2010 5088 1033 3975 1,621 329 1,266 35331 7177 27602

2015 5617 1141 4388 1,789 363 1,398 39008 7923 30475

2020 6202 1260 4845 1,976 401 1,544 43068 8748 33647

2025 6847 1391 5349 2,181 443 1,704 47550 9659 37149

2030 7560 1536 5906 2,408 489 1,882 52499 10664 41015



11.4.2 Options and feasibility assessment - Southern portion of Houay Longkong Stream.

For the improvement of the southern portion of Kaysone Phomvihane, the drainage system was envisioned with various options as below:

Sewage interceptor

Option 1. For the intercepting of wastewater from the area, a DHPE pipe will be used that is fixed at the bottom open drainage canal and install interceptors at every intersecting roads 10 numbers. For maintenance and cleaning control, concrete boxes for every 50m will be installed. The wastewater pipe will increase to the downstream ward, the pipe shall be secured in concrete embedding. For the last section after crossing the Phokadouath road, the wastewater pipe shallbe installedand connected to the newly constructed drainage canal to the wastewater treatment plant. The wastewater pipe will install a manhole for every 40m for the maintenance and cleaning purpose. This option1 is cheap and can practically be implemented to fit the existing situation since drainage open canal is already existing.

Figure 8: Typical overflow interceptor sewer




Option 2. Construct separately a wastewater drainage conduit in parallel with the existing drainage canal.The wastewater drainage conduit shall be installed on one side of the canal at an elevation lower than the storm drainage of the intersecting roads. For every intersecting road, the entering storm drainages have to accomodate expensive road crossing and four interceptors from the side drainages of each intersecting roads, causing inconvenience during the construction. Moreover, it will be expensive to arrange for connecting the households‟ wastewater pipes to the main wastewater pipe line, which today drains directly into canal. It will be too expensive an effort to inter-connect the sewerage system from both sides of drainage canal to the proposed separate wastewater drainage conduit by option 2.

Conclusion: Option 1 will be considered for the wastewater pipes, installing interceptors at every intersecting road. Maintenance and cleaning the concrete boxes every 50m will be arranged. This option is easy to perform and it is environmentally and economically considerable.



Figure 9: Manhole for maintenance of the sewerage pipe with 50m spacing





Drainage canal

For the construction of the drainage channel of last section of Houay Longkong natural stream, there are two options:

Option 1.The drainage canal after the box culvert under the Phokadouath road will be constructed with a width 4 m, side slopes 1:2 and 4m height. The bottom of Houay Longkong natural stream varies from 128.5MSL down to 127.00MSL. The bottom slab of outlet culvert is estimated to be about 124.00 MSL. The bottom of the new constructed canal will be set up at the upper end of the new canal to join with the bottom of the box culvert under road Phokadouath, which is about 129.00MSL, with the bottom slope (at gradient i=0.002). Therefore, at the end of the canal would be 128.00 MSL. If the ending of new canal will have a different level of elevation, the erosion, protection and scouring protection will be appropriate arranged. The canal bed will be excavated and some will be filled. The natural soil is sensitive to deformation and slope stability, the erosion protection would be suitable by loose riprap of crushed rock sizes 50mm to 300mm with a minimum thickness of 500mm, between crushed rock and soil so the geotextile should be used.

Option 2. The drainage canal to beconstructedall lined open canal following through Houay Longkong stream with the typical drainage canal used in Vientiane urban development and management project.For calculation the canal will be constructed with bottom width 4 m, side slopes 1:1.5 and 4m height. The bottom of the Houay

Figure 10: Storm drainage with the sewerage pipe



Longkong stream varies from 128.5MSL down to 127.00MSL within the canal section, therefore, the canal bedding will need cut and filling. The natural soil is sensitive to deformation and slope stability, with the steep slope design not favourable. The bottom with the reinforced concrete slab and concrete tiles for side slope protection will be expensive to repair in case of any deformation. The construction cost is about 30% more expensive than Option 1.

Figure 11: New drainage canalfollowing the Houay Longkong stream


Conclusion: Option 1 will be considered for the drainage canal with erosion protection, suitable with loose riprap of crushed rock sizes 50mm to 300mm with minimum thickness 500mm. This is ceasy to construct, easy to fix if there‟s any deformation, environmental friendly, and economically considerable. Wastewater treatment

For the construction of the wastewater treatment plant, there are two options:

Option 1. Construct Aerated Wastewater Treatment Plant forearthen impoundment in which mechanical mixing introduces air for BOD removal and suspend solids. Performance depends on aeration. Three cell systems are recommended. Agitation must be sufficient to suspend all solids. Detention time: 1.5 to more than 3days. The design for BOD removal is based on first- order kinetics and the complete mix hydraulics model. An aerated pond system would have supplemental air sources to provide dissolved oxygen, this is usually accomplished with surface mechanical aerators and mixers, or by various forms of diffusers supplied with compressed air



from mechanical blowers or compressors as shown in the Figure. For equal sized ponds, the aerated pond would provide the best treatment due to the mechanical addition of oxygen. For a given organic loading,it would require the least amount of land area.

The land proposed for the wastewater treatment plant is empty. No construction structures has been built on this area due to floods occurring during wet season. Pond is on excavation. The intake/interceptor has an elevation of about 129.00MSL, but the area where proposed wastewater treatment pond is about 130.0 MSL. The top dike would be at elevation of 132.00MSL to avoid potential flooding. Pumping the wastewater from the preliminary wastewater treatment ponds up to the Aerated Wastewater Ponds(Lagoons).

Figure 12: Typical Aerated Wastewater Treatment Plant

Source: GMS Corridor Towns Development Project. (TA7644-REG)

Figure 13: Typical Aerated Wastewater Treatment Plant


Option 2.An anaerobic pond is a deep impoundment, essentially free of DO. The biochemical processes take place in deep basins, and such ponds are often used as preliminary treatment systems. Anaerobic ponds are not aerated, heated or mixed.

http://en.wikipedia.org/wiki/File:Surface-Aerated_Basin

http://en.wikipedia.org/wiki/File:Surface-Aerated_Basin



They require a very substantial area that is not available. The following figure illustrates the system.

Figure 14: Treatment system with anaerobic and sedimentation ponds


Conclusion:Aerated ponds discussed in Option 1 require less land. They are usually designed with a shorter retention time. They have been used to treat raw, screened or primarily settled municipal wastewater, as well as higher strength biodegradable industrial wastewater. The process is reliable, relatively easy to operate and cost effective. The advantages include reliable BOD5 removal; significant nitrification of NH3possible with sufficient mean cell resident time; treatment of influent with higher BOD5 in less space; and reduced potential for unpleasant odors.

Stormwater pumping

For the construction of the drainage pump station,there is only 1 option:

Option 1. During the wet season, the existing drainage system and flood control are not functioning. The water level at Mekong and Houay Longkong goes up level. Flooding is normal during peak run-off in August. It requires lowerwater level on the inland side andit is the only way to construct drainage pump station and sliding gates by extending the existing culvert boxes. This will require large water flows to be pumped and will result in higher pump installation and operation costs. If storage is used to reduce peak flow rates, a routing procedure must be used to design the system. The routing procedure integrates three independent elements to determine the required pump rate: an inflow hydrograph, a stage-storage relationship and a stage-discharge relationship.

The well-know pump technology on the bearing bracket is constructed in accordance with best practice standard and completes the performance range up to max.1800 m3/hr. A lot of flowing objects can be found on the drainage canal. This causes a problem on the pump. It is recommended that screens be used to prevent large objects from entering the system that possibly damage the pumps. Larger debris may be screened either at the surface or inside the wet well/storage system. In the wet-pit station, the pumps are submerged in a wet well or sump with the motors and the controls located overhead. With this design, the storm water is pumped vertically through a riser pipe. The motor is commonly connected to the pump by a long drive shaft located in the center of the riser pipe (see Figure 9 for a typical layout). Another

Receiving tank

Anaerobic

organic pond

Optional: wetland

Sedimentation

pond

Sewage from

collection system

Receiving recipient



type of wet-pit design involves the use of submersible pumps. The submersible pump commonly requires less maintenance and less horsepower because a long drive shaft is not required. Submersible pumps also allow for convenient maintenance in wet-pit stations because of easy pump removal. Submersible pumps are now available in large sizes and should be considered for use in all station designs. Rail systems are available which allow removal of pumps without entering the wet well.

Figure 15: Typical stop gate and drainage pump station


Conclusion: No other option can be seen to show the problem of flood mitigation for this drainage system.

The Houay Longkong outlet today found no indication of erosion development from a normal natural flooding. Protectingthe pump station and providing aesthetic appearance areto be considered on this project.



11.4.3 Options and feasibility assessment - Central drainage system around the Savanxay Market area

Wastewater treatment

To improve the wastewater generating from Savanxay Market and bus terminal areas, including the southern catchment Soukhavadi, Samosone Phokadouath proposes the following options:

Option 1. With the main objective of wastewater treatment generating from this area before releasing to the the Mekong river and in the consideration of budget under the project implementation, the town will need to adopt the most suitable and fittingoption. On this central drainage system subproject, no work to improve the drainage channel on the southern side of Visoukan road is needed except to intercept the wastewater from this drainage after crossing the Chomkeo road to the wastewater treatment plant. The drainage around the market area will construct a total of 1,000m.The drainage will adopt urban drainage structures (pipes culverts, manholes, gutters and chamber, etc.) with top cover by base course materials and grassing to improve the environment. The northeast drainage of the market will be connected to the southern part with the same standard as urban drainage.Wastewater from the market area will be interconnected to the urban drainage and conveyed to the wastewater treatment plant. The wastewater from the market area will be collected through gutters and chambers then connected to pipes culverts with HDPE.The wastewater is conveyed to the wastewater treatment plant at Chomkeo stream outlet. The existing culvert crossing Chomkeo road from both sides of Visoukan road, during the low flow weather, the wastewater from these Visoukan road side drainages will be intercepted to waste water treatment plant constructed in kind of a septic tank. To adopt this type of treatment plant is the only option.Available land belongs to the government.

Implementing the improvement of drainage system around the Savanxay Market and constructing a wastewater treatment plant at the end of drainage system are respondes to the requirement of National Strategy on Environment for the year 2020 and its action plan for the years 2006-2020.Its objectives are to realize environmental management, to implement measure for sustainable development, to secure sustainable use and equitable access to water resource and to use land with securing ecosystem.

Option 2. The drainage system will be constructed, similar to option 1, but the wastewater plant will be constructed alongside the drainage line and Visoukan road. This option is too complicated and expensive to arrange. The wastewater from the southern Visoukan roadside drainage is too deep.

Conclusion: Option 1 is relatively easy to construct, economically considerable, environmental friendly, and makes use of the land available.

11.4.4 Options and feasibility assessment - Northern portion of Kaysone Phomvihane drainage system

The development of the northern drainage system is not critically polluted.The increasing number of domestic households, commercial establishments, small factories and industries, mechanical workshops and vehicle washing and services shops that make the town expand will cause the wastewater going to the drainage system to increase. Since the urban drainage system has not been established, wastewater from households currently remains stagnant within the community area. The drainage and wastewater of the community are worsening and the soil environment is getting polluted. To improvethe northern portion of the drainage system, it is considered to construct the main drainage pipe



to convey wastewater to the treatment plant at downstream of Houay Khilamang. The wastewater during the dry weather condition shall be intercepted at the end point of existing drainage canal. The drainage pipe will start from this point and was measured at an elevation intake/interceptor pipe of 132.4MSL (top canal slope about 135.0MSL). Measurement at the proposed area for construction of wastewater treatment plant about is 132.5 MSL (bottom stream is 130.00MSL).

In addition to the northern drainage system, an urban drainage of 1,130m long (pipes culverts, manholes, gutters and chamber etc.) for area adjacent to the northern side of Savanxay Market drain to Houay Khilamang is to be constructed. During dry season, the wastewater will be transmitted to treatment plant through a pipe line by arranging a sewer to intercept the wastewater.

Figure 16: Typical Interceptor Sewer Concept in Northern system


The wastewater pipe shall be installed underground along the left bank of Houay Khilamang stream to convey wastewater from the northern service area to the wastewater treatment plant. The wastewater pipe adopted diameter of D400mm, 0.75km long, which is estimated to secure for 20 years up to Year 2030 with a population of 41,015 inhabitants. Connected to the drainage line, a man-hole for every 40m will be installed for the maintenance and cleaning purpose. For the drainage canal, sewerage connection pipes



with D100mm of HDPE for every 30m will be installed for future connection to households. The elevation at the end of wastewater drainage (outlet to the wastewater treatment plant) is estimated =132.5-L*i=132.5-700m*0.0015=131.45m. There is difference of elevations between the intake connecting to the wastewater sources and the elevation of the area proposed for the wastewater treatment plant. Pump and excavation for wastewater treatment plant (Aerated Wastewater Ponds). This is the only alternative for wastewater treatment that is relatively cheap and practically easy to implement to fit the natural condition.

For this drainage system, it has considered the flood control mitigation. The observation of high flood in August-September 2011 and the consultant‟s assessment reported that the high flood was observed to be 133.00 MSL.The value of construction works to the Houay Khilamang drainage outlet structure to function estimatesof capital investment about $0.5M, plus costs for O&M.

11.5 Conceptual engineering solutions and design

11.5.1 Engineering design - wastewater pipeline layout and longitudinal profile

The proposed route of the wastewater pipe line is shown on the following figures, and the longitudinal profile is shown in annex 2 together with the detailed layout and design analysis. The wastewater pipe profile has been established, taking into consideration the following factors:

Interceptor sewer: the wastewater pipe line is mandatory to fix at the bottom of existing lined open canal, with the slope at a gradient of about 0.003125. The interceptor sewer will receive wastewater from bottom canal into manhole at every intersecting roads and the maintenance manholes will be arranged at every 50m.

Self-cleansing: the wastewater pipe line will receive surface water runoff, which will tend to contain larger quantities of grit than sanitary wastewater, and must be designed to be self-cleansing throughout its service life especially in the years when flow rates are lower. The sewers have been designed to suspend sand particles having a bigger diameter can be suspended in the manholes either will clean up during the high water or manually.

Sulfide Generation: the wastewater pipe line is designed to maintain flow velocities of about 0.6 to 0.9 m/s to help to minimize excessive sulfide production.

Hydraulic Capacity: Sewer hydraulic capacity is sufficient to meet projected requirements throughout the service life of the pipe material. The capacity of wastewater pipe line is designed for 20 years.



Figure 17: Overall Plan and Layout of Kaysone Phomvihane drainage and wastewater treatment system




Figure 18: Layout - Southern wastewater and drainage system




11.5.1 Design data for pipelines and canals

The following tables present the design data for the pipelines and canals.



Location: Southern drainage system, Between the Phokadouath road and downward to WWTP

Type Circular Pipe

Diameter, mm 400

Length of the pipe, m 40 specing between menholes

Item Symbol Unit Case Remark

Qave

Flow Q m3/d 7560 Q=0.8pi x wc ÷ (1,000)

Flow q m3/s 0.0875 q=0.8pi x wc ÷ (1,000)*86400

Diameter D m 0.40

Flow area A m2 0.1256 A=3.14*D 2̂/4

wet perimeter length P m 1.256 P=3.14*D(in full flow)

Radius depth R m 0.1000 R=A/P=D/4

Velocity V m/s 0.6966 V=q/A

Length L m 40

Gradient i 1/1000 0.0005 Manning formula i=(n2*V2)/r (̂4/3)

Fliction loss hf m 0.0189 hf =i*L

Velocity head V 2̂/2g m 0.0049

hs =k*V2/2g; k=0.5 at entrance 1.0 at exit.

K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90

deg.bend

Minor loss hs m 0.002

Total loss h m 0.021 h=hf+hs

Location: Southern drainage system,between the canal junnction to Phokadouath road

Type Circular Pipe

Diameter, mm 400

Length of the pipe, m 50 spacing between menholes


Qave

Flow Q m3/d 7173 Q=0.8pi x wc ÷ (1,000)

Flow q m3/s 0.0830 q=0.8pi x wc ÷ (1,000)*86400

Diameter D m 0.40

Flow area A m2 0.1256 A=3.14*D 2̂/4




Length L m 50





K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90

deg.bend





Location: Southern drainage system, between the canal junction and upward

Type Circular Pipe

Diameter, mm 300



Qave

Flow Q m3/d 2952 Q=0.8pi x wc÷ (1,000)

Flow q m3/s 0.0342 q=0.8pi x wc ÷ (1,000)*86400

Diameter D M 0.30

Flow area A m2 0.07065 A=3.14*D^2/4

wet perimeter length P M 0.942 P=3.14*D(in full flow)

Radius depth R M 0.0750 R=A/P=D/4


Length L M 50

Gradient i 1/1000 0.0004 Manning formula i=(n2*V2)/r^(4/3)

Fliction loss hf M 0.0196 hf =i*L

Velocity head V^2/2g M 0.0119 hs =k*V2/2g; k=0.5 at entrance 1.0 at exit. K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90 deg.bend

Minor loss hs M

0.005

Total loss h M 0.024

h=hf+hs

Note: the diameter of pipe line is on the big size but the area also high populated

Location: Northern wastewater pipe line

Type Circular Pipe

Diameter, mm 400



Qave

Flow Q m3/d 5906 Q=0.8pi x wc÷ (1,000)

Flow q m3/s 0.0684 q=0.8pi x wc ÷ (1,000)*86400

Diameter D M 0.40

Flow area A m2 0.1256 A=3.14*D^2/4

wet perimeter length P M 1.256 P=3.14*D(in full flow)

Radius depth R M 0.1000 R=A/P=D/4


Length L M 50

Gradient i 1/1000 0.0004 Manning formula i=(n2*V2)/r^(4/3)

Fliction loss hf M 0.0220 hf =i*L

Velocity head V^2/2g M 0.0134 hs =k*V2/2g; k=0.5 at entrance 1.0 at exit. K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90 deg.bend

Minor loss hs M

0.005

Total loss h M 0.027

h=hf+hs




11.5.2 Conceptual design - new section of southern stormwater drainage canal, layout and longitudinal profile

The proposed new drainage canal after the box culvert under the Phokadouath road will be constructed with bottom width of 4m, side slopes 1:2 and 4m in height. The bottom of Houay Longkong natural stream varies from 128.5MSL down to 127.00MSL. Therefore, the bottom of the newly constructed canal is set up so that the upper end will join with the bottom of the box culvert of about 129.00MSL, with the bottom slope (at gradient i=0.002), then at the end of canal would be 128.00 MSL.The canal bed will need excavation and filling. The natural soil is sensitive to deformation and slope stability, for the erosion protection would be suitable by loose riprap of crushed rock sizes 50mm to 300mm with minimum thickness 500mm between crushed rock and soil the geotextile shall be used.

The design of longitudinal of drainage canal with bottom slope (at gradient i=0.002), for flushing sediments at the last period of rainy season.

Table 11: Runoff calculation and test of canal capacity with Rational Method

note: The Concept of the design for new canal section: the dimensioning of the canal cross section has been calculated with rational method, that also has considered the results of the analysis of short duration of high rainfall intensity from the Figure 6: rainfall frequency Tr=10 years of return with 60 minutes duration, the intensity of 34.566 mm/hr is applied.

Source Government of Lao PDR. Province of Savannakhet. Kaysone Phomvihane Rainfall Frequency. 2010.

The design cross section of drainage canal with bottom canal width 4m and the side slope of 1:2 have the following reasons: (i) to meet the discharge capacity of canal during the peak runoff, (ii) to comply with the requirement of slope stability, and (iii) to have a volume of reservoir to absorb the peak flow rates for a routine procedure of pump station

Runoff calculation and test of canal capacity with Rational Method

A=5.9Km2

C=0.5

i=234/24 9.75

Q=0.278 x C x A x i 7.996 m3

/S

Q= Peak flow in cubic metres per second (m3/s)

A= Catchment size in square Kilometres (Km2)

Tc=(0.87 x L3/H)

0.385

B

Tc=Time of concentration (minutes)

L=Length of stream/river (Km)

1 h=3m

H=Differential elevation along the stream (m) m=2 θ=º

L=4.1Km b=4

H=28m

Rational Method

Kaysone Town at Savannakhet Province

Rainfall Frequency 10 year(s) A =(b+m*h)*h A= 30.00

DRAINAGE SYSTEM DESIGN

Waterwa

y No.Station Area L H Slope (%) C Tc Intensity Q (m3/s) Max

Velocity

Flow

Area

km2 km m min mm/hr

1

Southern

drainage

system H.

Longkong

5.900 4.10 28 1% 0.50 80.4 34.566 28.348 1.500 18.899 0.9

Internal

Pipe

Diameter

. (m)

Trapezoid

canal

(V=m/s)

C= Runoff coefficient (1.0 for hilly terrain - slopes >10%,

0.5 for rolling terrain - slopes 5 - 10% and 0.3 for flat

terrain - slope<5%

I = Rainfall intensity in millimetres per hour (mm/hour) for

the duration corresponding to the time of concentration for

each catchment area



operation. The routing procedure integrates three independent elements to determine the required pump rate; an inflow hydrograph, a stage-storage relationship and a stage-discharge relationship.

11.5.3 Design considerations and analysis for proposed wastewater treatment ponds in the southern and northern systems.

Aerated wastewater lagoons are large volume wastewater treatment systems and can be designed to match nature.The following recommendations apply for the treatment of mainly domestic wastewater or comparable commercial wastewater.

In aerated wastewater lagoons, oxygen is introduced using mechanical aeration installations. Through this the 'large area requirement, as is necessary with nonaerated wastewater lagoons, is reduced. They are fed with raw wastewater or mechanically pretreated wastewater and serve for biological treatment. For aeration, in general, aerators specially designed for lagoons are employed; at the same time they effect a circulation. Dimensioning criteria for satisfactorily thorough mixing are either the BOD5 volumetric loading or the BOD5 solids loading. Their employment for storm water treatment is, as for nonaerated lagoons.

For the dimensioning of aerated wastewater lagoon, a BOD5 volumetric loading of BR< 25 g/(m3. d) is to be applied. If measurement is carried out according to area loading

then the equation:

BA = BR·h

applies for normal water depths h = 1.5-3.5 m. The hydraulic retention time with dry weather must be at least two (2)days.

As OC load OB≥1.5 kg/kg and, for the circulation according to the system employed

and the hydraulic characteristic of the lagoon, a power per unit volume of reactor WR = 1 - 3 W/m3 are to applied. It is sensible to divide the total volume into two series connected units. The secondary treatment zone or a downstream non-aerated lagoon is also to be provided with at least one day‟s hydraulic retention time. With the above given dimensioning values the nitrification is small. If it is required, aerated wastewater lagoons with fixed bed installations, eg. biological filters, biological contactors or integrated growth surfaces can be combined together.

The wastewater lagoons are to be matched to the local conditions and, in shape, to the aeration equipment employed.

Secondary sedimentation lagoons serve for the separation of the deposit able substances contained in wastewater and for the digestion of the deposited sludge. The bottom of the lagoon should have a slope to a low point from which to pump out the sludge.

For the design the following are to be observed:

Volumetric loading BR < 25 g/(m3.d) Solids loading g/(m2.d) BA = BR·h As OC load OB ≥1.5 kg/kg

power per unit volume of reactor WR = 1 - 3 W/m3

Hydraulic retention time with dry weather tR ≥1 d Hydraulic retention time secondary sedimentation tR ≥2 d

Aerated Lagoon BOD5 Removal Rate(%) tempt >20C 65% Inclined embankment/excavated pond slopes ≥1:3 Length to width (on the surface) ≥3:1 Normal water depths h ≥1.5-3.5m (2.5m) Freeboard ≈ 0.3-0.6 m (0.6m)

Apart from the regular control of the operation and servicing of the mechanical installations only the normal cleaning and maintenance tasks such as, for instance, the



skimming of floating substances, cleaning of the inflows and outflows, repair of damage to the retaining walls, are to be carried out. According to the aeration system there are, for the clearance of sludge, intervals from four to ten years. Sludge production should be set at 0.3 I/(I·d).

The soil properties foundation at the location proposed for the Aerated wastewater lagoons are dense clay with low permeability values and don‟t require sealing measure. However, the bottom of wastewater lagoons require riprap protection with the crushed rock 50-300 mm, minimum of riprap thickness is 500mm, under riprap the geotextile would be necessary. The riprap protection on the bottom is for for cleaning up/removal of solid sediment.

The ideal configuration of a pond designed on the basis of complete mix hydraulics is a circular or square pond. However, even though partial mix ponds are designed using the complete mix model, it is recommended that the cells be configured with a length-to-width ratio of 3:1 or 4:1.This is because it is recognized that the hydraulic flow pattern in partial mix systems more closely resembles the plug flow condition.

In Annex 3, the detailed design analysis and calculations are presented.

11.5.4 Design and Engineering solutions of the southern storm water drainage system and flood control mitigation with drainage pump station

Storm water pump stations are necessary to remove storm water from flood area that cannot be drained by gravity. Because of high costs and the potential problems associated with pump stations, their use is recommended only where other systems are not feasible. When operation and maintenance costs are capitalized, a considerable expenditure can be justified for a gravity system. If this is the case, there is no other system that can replace the proposed drainage pump station.

Typical pump station design procedures seen in the literature do not represent most highway storm water pump station situations. Many storm water management plans limit the post development discharge to that which existed prior to the development. In order to meet this requirement, it is often necessary to provide storage in the system. Traditional pump design procedures have not considered this storage volume and are thus oriented toward only wet well volumes. These designs are required to pump higher rates with limited storage volumes and thus start-stop and cycling relationships are very critical and can consume considerabledesign effort.

The mass inflow curve procedure which was not discussed in this document is commonly used when significant storage is provided outside of the wet well. The plotting of the performance curve on the mass inflow diagram gives the designer a good graphical tool for determining storage requirements. The procedure also makes it easy to visualize pump start/stop and run times. In the event that a pump failure should occur, the designer can also evaluate the storage requirement and thus the flooding or inundation that could occur.

Design Considerations

Pump station design presents the designer with a challenge to provide a cost-effective drainage system that meets the needs of the project. There is a long procedure of considerations involved in their design. Below is a listing of some of them:

o Wet-pit vs. dry-pit o Type of pumps o Number and capacity of pumps o Motor vs. engine drive o Peak flow vs. storage o Force main vs. gravity o Above grade vs. below grade o Monitoring systems o Backup systems o Maintenance requirements



To assure cost-effectiveness, the designer should assess each choice and develop economic comparisons of alternatives on the basis of annual cost. However, some general recommendations can be made which will help minimize the design effort and the cost of these expensive drainage facilities. These recommendations are discussed in the following pages.

Location

Economic and design considerations dictate that pump stations be located at the outlet of existing drainage culvert, the design of pump house will connect to the existing structure. It is recommended that the details design shall carefully measure the existing structures and the extending design of culvert and pump station should comply and connected to the existing. Any results from the soil survey of pump house station design should be taken in account.

It is assumed that construction of the pump house station is on a separate location from the existing location and will double the works for instance the inlet conduit, flab and sliding gates and to cut of traffic during the construction. Economic and practicality would be considerable to extend the existing culvert structure.

Hydrology

Because of flood areasare paddy field and village, pump stations will serve the convenience of the population and other commercial establishments.The wastewater treatment plant is designed to accommodate a 10-year storm. It is trading between the design to prevent of the extent of flooding which causing inconvenience with the associated risk and excessive investment.

The design should consider storage, in addition to that which exists in the wet well, at pump station site. For most flood control pump stations, the high discharges associated with the inflow hydrograph occur over a relatively short time. Additional storage, skillfully designed, may greatly reduce the peak pumping rate required. An economic analysis can be used to determine the optimum combination of storage and pumping capacity. Because of the nature of the sites where the inconvenience and losses related pump stations are located, it is usually necessary to locate storage well below normal ground level.

The design will require large flows to be pumped and will result in higher pump installation and operation costs. If storage is used to reduce peak flow rates, a routine procedure must be used to design the system. The routing procedure integrates three independent elements to determine the required pump rate; an inflow hydrograph, a stage-storage relationship and a stage-discharge relationship.

Collection Systems

Storm drains leading to the pumping station are designed through the existing convert and the pump sump is on top of culvert to minimize depth and associated construction cost. To avoid siltation problems in the collection system, a minimum grade that produces a velocity of 1 m/s in the pipe while flowing full was projected and at the front of the culvert is a relatively big reservoir with almost low velocity. Minimum cover or local head requirements should govern the depth of the uppermost inlets.

The high water level on August 2011 was recorded approximately 132.5MSL about 1.5m below the top road, on both side of the road the water levels were the same. To lowering water level inland only by pumping and keep the water level inland side down to 129.0MSL. The area proposed for construction of wastewater treatment has an elevation of 130.5 to 131.5MSL to be kept dry, most of the time the storm inflow will drain by gravity flow.

The pump station will start operation only when water level at Mekong is higher than 127-128.0MSL, otherwise the inflow will drain by gravity flow through the existing culvert. The pump station is expected to operate for some year.

The new drainage canal should preferably terminate at upstream of possible area for creating a natural reservoir. The reservoir can absorb some excessive inflow and the



sedimentation can settle in the reservoir, the sediments will be flushed out at the period ending of rainy season. During the construction stage,a budget was allocated for landscaping and excavation of natural reservoir. This is to avoid siltation problems in small reservoir, a minimum grade of 2% should be used.

It is recommended that screens in front of culvert and at pump sump shall be used to prevent large objects from entering the system and possibly damaging the pumps. Larger debris may be screened either at the surface or inside the wet pit pump sump system. The level of maintenance require a lot of time.Pump station could be in operation for one month per year. For the dry season, the water level at the Mekong is lower than 127-128.0MSL and will not require pumping.

Pump station type

As it has been recommended on previous section 4.8.1, the type of the pump station is wet-pit station. In the wet-pit station, the pumps are submerged in a wet well or sump with the motors and the controls located overhead. With this design, the storm water is pumped vertically through a riser pipe. The motor is commonly connected to the pump by a long drive shaft located in the center of the riser pipe (see Figure 9-1 for a typical layout). Another type of wet-pit design involves the use of submersible pumps. The submersible pump commonly requires less maintenance and less horsepower because a long drive shaft is not required.

Submersible pumps also allow for convenient maintenance in wet-pit stations because of easy pump removal. Submersible pumps are now available in large sizes and should be considered for use in station designs. Rail systems are available which allow removal of pumps without entering the wet well.

Submergence is the depth of water above the pump inlet necessary to prevent cavitation and vortexing. It varies significantly with pump type and speed and atmospheric pressure. This dimension is provided by the pump manufacturer and is determined by laboratory testing. A very important part of submergence is the required net positive suction head (NPSH) because it governs cavitations. Net positive suction head is the minimum pressure under which fluid will enter the eye of the impeller. The available NPSH should be calculated and compared to the manufacturer's requirement. Additional submergence may be required at higher elevations. As a general rule, radial flow pumps require the least submergence while axial flow pumps require the most.

Trash Racks and Grit Chambers

Trash racks should be provided at the entrance to the wet well if large debris is anticipated. For storm water pumping stations, simple steel bar screens are adequate. Usually, the bar screens are inclined with bar spacing approximately 38 mm (1.5 in). Constructing the screens in modules facilitate removal for maintenance. If the screen is relatively small, an emergency overflow should be provided to protect against clogging and subsequent surcharging of the collection system. Screening large debris at surface inlets may be very effective in minimizing the need for trash racks.

Natural storage volume

Construction of drainage system and flood control is associated with the storage capacity of the pump intake, during the construction of drainage canal, landscaping the area and improving the natural reservoir in front of pump intake to serve as absorbing capacity when the rainfall intensity is high, the result from the calculation of runoff to stream and analysis by Rational Method for the system the inflow Q=28.3 m3/s and estimated volume of intake reservoir included canal body, natural ponds to absorb the runoff V=99,750m3, and the estimate time to fill up reservoir with the high rainfall intensity t =>99,750 m3/28,3 m3/s=3,525 s or 1hr, the reservoir will fill up in about one hour and the pump capacity will empty the reservoir in 27hrs, in reality the reservoir will rise gradually, while the pump will also be lowering down the water level before the run off arrive. Qpump= 2x0.5 m3/s =3.600m3/hr.



11.5.5 Design and Engineering solutions on the drainage improvement of the central area around Savanxay Market and bus terminal.

A storm drain is the portion of the roadside drainage system that receives surface water through inlets and conveys the water through conduits to an outfall. It is composed of different lengths and sizes of pipe or conduit connected by appurtenant structures. A section of conduit connecting one inlet or appurtenant structure to another. The storm drain conduit is most often a circular pipe, Appurtenant structures include inlet structures, man holes, junction chambers, and other miscellaneous structures.

The design consideration for this subproject of the drainage improvement for the central area around Savanxay Market is based on the urban drainage regulation for the roads construction. The design has adopted typical design ofroadside drainage system which applies for Kaysone road subprojects. The size of circular pipe drainage line with 1m diameter, and for every 30m provide with a access holes (manholes) the surface water or wastewater in the dry weather condition is catched from the catch basin, gutters and chamber, wastewater pipe from the building, etc. of the roads or market area and connecting to the pipe culvert by the DHPE pipe connector with diameter of D160 mm or D100mm. The designs of the catch basin, gutters and chamber the various typical drawings from the urban drainage manual can be applied. The gradient of the pipe culvert shall be set up according to the urban drainage standard. The access holes shall be covered with the concrete, the drainage route shall be covered with suitable soil, compacting base courses material, grassing possible for parking or other public use.

The wastewater shall be transmited though the pipe culvert to the wastewater treatment plant installing at the left bank Chomkeo stream outlet. The wastewater treatment plant a kind of septic tank which is normal used in big building, schools, with a series cells as the land available to accommodate the treatment plant. The wastewater will intercept by overflow interceptor sewer at the culvert outlet and distribute to the treatment plant through concrete cutter and plastic pipes to each cell.The wastewater will go through two settling tank then though filters before release to the creek again. The erosion protection around the treatment plant shall be arranged with the riprap and grouted riprap. The wastewater treatment plant is expected to flood by the high level of Mekong.It will be cleaned up from time to time by vacuum tank. For monitoring of wastewater treatment capability,it is recommended to have sampling and analysis of wastewater before and after the treatment plant.

11.6 Civil and structural Design Criteria and basis

11.6.1 Codes and Standards

The following design criteria indicate the main data which are used for the structural design and calculations of the civil works. The design codes used are indicated as well as additional specific criteria.

The Improvement of Drainage Structures and Installation of Wastewater Treatment Plantat Kaysone Phomvihane comprise lining of sewer‟s pipe line to the bottom of existing canal, underground with access holes, construction of drainage canal and wastewater treatment ponds(lagoons) with a slope erosion protection by riprap, drainage pump station and various concrete structures for culverts structures.

11.6.2 Requirements for Earth works:

Only approved materials shall be used in the construction of embankments and backfills.

Grading Requirements



Materials for structural backfill/free drainage backfill in embankments shall consist of gravel, crushed gravel, crushed rock, natural sands, or combinations thereof. Granular materials that will produce a dense, well compacted backfill shall be used. Backfill materials in subgrade layers, sub-base and base courses shall meet the requirements stipulated in the relevant Sections of these Specifications and are shown in Annex 4.

11.6.3 Requirements for civil/construction works

Details to be applied for this are presented in Annex 6.

11.6.4 Drainage and Protection Strengthening Works

Requirements for Finished Products

Pipe ends shall be perpendicular to the walls and the longitudinal axis of the pipe. The inner and outer surface of the pipes shall be even and smooth. The whole pipe shall be free from fractures, cracks, honeycombing, open texture, spalls and surface roughness. The permissible variations in dimensions shall be as specified in AASHTO M 170 M, unless otherwise permitted by the engineer.

Wall thickness more than that required by the Drawings shall not be a cause for rejection. Pipes having local variations in wall thickness exceeding those specified in AASHTO M 170M shall be accepted, when the three-edge bearing strength and minimum steel cover requirements are met.

Loose Riprap

Unless otherwise shown on the Drawings, riprap stones shall be of size 300 - 500 mm, with a bedding of stone size 50 - 100 mm, and placed on a filter fabric.

Riprap shall be made of approved sound, angular quarried rock or angular blocks from the riverbed. Each block shall be placed individually commencing with the larger blocks placed in contact with each other and all voids filled with carefully selected blocks so as to produce a neat surface of interlocking blocks. Laying of riprap shall commence at the downstream end of the area to be protected and shall proceed against the direction of flow.

Grouted Riprap

Grouted riprap shall be made of stones of size 100 - 200 mm placed on firm excavated and trimmed ground which is covered by a filter fabric.

Filter Fabrics

Filter fabrics shall be durable non-woven geotextiles or synthetic fibres unaffected by soil acidity, soil alkalinity and bacteria. The fabric shall be made by an approved, reputable manufacturer and shall have a mass and strength at least equal to the following criteria:



Table 12: Specific specification requirement for geotextiles

Mass g/m

2

Wide Strip Tensile Strength kN/m

Mullen Burst Strength kPa

Under Drainage Material Under Gabions, Gabion Mattresses or Grouted Rip-Rap Under Rip-Rap

180 250 300

Mean 12/12 Mean 18/18 Mean 21/21

2160 3040 4200

Source:Government of Lao PDR. Province of Savannakhet. District of Kaysone Phomvihane. Bank erosion protection in Pakadan and Wat Muangkao, September 2005

11.6.5 Revegetation

Revegetation of disturbed (excavated) areas is a requirement of the EMP. Revegetation is used to stabilize areas and protect areas against erosion. Almost all excavated areas will require revegetation. The contractor shall revegate disturbed areas for landscaping and erosion protection of slopes and other areas as shown on the drawings, to meet EMP requirements or as instructed by the engineer.

Revegetation may be carried out by seeding, sodding or turfing. Revegetation is carried out only after the area has been re-topsoiled to a depth of 100 mm and fertilizer has been mixed in.

The revegetated areas shall be kept moist by sprinkling water as long as needed to obtain a good and strong vegetation cover. This must normally be done until the areas have achieved an established ground cover of 98%. For turfed areas cover may be assessed only after the area has been established by this method for 1 month.

11.6.6 Electro Mechanical Design

The wastewater pump stations will preferably be located at the end of wastewater pipe line and close to site along the east side boundary of WWTP to maximize isolation distances and minimize the potential for noise and odor environmental impacts.

Allocated site area will provide space for future expansion. Water supply to the pump station for fire-fighting, wash down, cleaning and flushing will be from the WWTP effluent process water supply system. The source of electricity supply from EdL 22 kV transmission line passing near by the sites.

11.6.7 System Hydraulics

Capacity

The capacity of the pump stations shall be equal or greater than the peak hourly design flow. In addition to establishing the peak design flow, it is also necessary to review minimum flows and determine how the station will operate under low flow conditions.

Pumps and Wetwell

The pump station will employ constant single or multiple constant speed pump sets with capacities selected for optimum operation under dry weather and wet weather flow conditions over the full range of system operating characteristics. The sequence of pump operation will be controllable to ensure uniform pump operation duration and wear of critical parts. Pumps will be provided with mechanical seals. An ample supply of spare parts, lubricants and other maintenance materials will be delivered with the pumping and related equipment. The number of pumps selected will allow the station to provide the peak design



flow with the largest capacity pump out of order. The dry well will be provided with a vacant pump set bay for the future installation of a pump set for augmentation of pump station capacity. The number of the pumps shall correlate to the wetwell size and prevent excessively short periods between pump starts. Pumps shall be of the non-clog type and be capable of passing a 100 mm diameter sphere.

Twin interconnectable wetwells will be provided. Wetwells will be designed to provide acceptable pump intake conditions, adequate volume to prevent excessive pump cycling, and sufficient depth for pump control while minimizing solids deposition. Wetwells and pump selection will be designed to minimize solids buildup such as grit, grease and other floatables and to facilitate solids removal.

Clogging Protection

Coarse bar screens will be required upstream of the pump station wetwell to protect the pumps from clogging. The screening chamber shall be mechanically ventilated and readily accessible for manual clearing of screens and removal of screenings. The screening chamber shall be integral with the wetwell and designed to the same ventilation, odor control, and hazardous area standards.

11.6.8 Odor and Noise Control

The design of both the pump station and the interceptor sewer will incorporate planning and construction techniques that consider odor and noise-producing conditions and solutions. The physical layout of the pump station will allow for a variety of accessory systems to be applied that meet whatever odor concern may be indicated. The expected waste load and associated chemical and or unusual physical characteristics, as well as the detention time and hydraulic characteristics of the interceptor sewer, screening area and wetwell should be considered. Specific odor control facilities will be identified in detailed design.

The most significant sources of noise will be emergency generators which produce mechanical intake air or exhaust stack noise. A variety of sound insulation schemes will be investigated in detailed design to reduce the effects of noise from these sources and the optimum grade of silencing will be recommended to meet occupational and neighborhood environmental standards.

11.6.9 Special Design Details

Electrical Design Codes of Practice

Electrical design for the pump station shall conform to international and national codes and standards including the US National Electrical Code (NEC), and US National Electrical Safety Code (ANSI). Particular attention will be given during detailed design to classifying the various enclosed spaces to ensure adequate ventilation, and using explosion-proof electrical equipment where required.

Instrumentation

Instrumentation will include, at a minimum, pump run times, pressure gauges, and voltage/ ampere meters for the motors.

Alarms

Alarms will include:

• high wetwell water level • low wetwell water level • power failure • pump failure • engine generator failure



• fire alarm • pump station intrusion.

Lighting

Adequate lighting will be provided in all equipment areas to allow for repair and maintenance during daylight and non-daylight hours.

Water Supply

Potable and flushing and wash-down water will be available from the WWTP potable and process water supply system.

Equipment Removal and Replacement

Pump station design shall provide accessibility for loading and offloading for equipment removal and replacement. Access provided will include doors, vaults, and roof access Panels for all major equipment items including:

• pumps and motors • electrical panels • valves • engine generators.

Permanent monorails and hoists will be provided with a lift rating at least equal to the largest piece of equipment.



12 COST ESTIMATES

12.1 Subproject Investment costs

12.1.1 Market Rates and Prices

The cost estimates of the project are based on recent level of the rates, prices and exchange rates. Current market prices of construction materials, equipment and skilled/ unskilled labour rates were obtained from local and international commercial establishments, local contractors and previous tendered prices. Based on these rates and prices, the price for each construction activity was developed. The following considerations were taken into account:

costs for procurement of pipes, fittings and equipment is in foreign currency, construction work has both foreign and local currency components and based on the prices provided by local suppliers and agencies;

rates and prices were compared with other similar project in Laos neighboring countries.

The estimates include civil and electrical/mechanical work to construct the Kaysone improvement drainage systems, wastewater treatments and drainage pump station for flood control subproject facilities. The wastewater treatment includes the distribution pumps stations with chambers, Aerated lagoons, Secondary Sedimentation Lagoons, sludge beds, maturation ponds, administration building and ancillary facilities. The estimates include excavation cost, crushed rock suppliers, aggregates for concrete works, blinding concrete, reinforced concrete, reinforcement, formwork, backfill, compaction, sewers and piping, overflow inceptors and drain piping and access road.



12.1.2 Cost Analysis

Table 13: Cost analysis for the Kaysone Phomvihane Wastewater Treatment Subproject.


The assumption of costs analysis for respective subproject

Amount

(US$)

Percent

(%)

Amount

(US$)

Percent

(%)

Amount

(US$)

Percent

(%)

Amount

(US$)

Percent

(%)

Amount

(US$)

Percent

(%)

I

1.1

Lining a sewerage pipes 2.5km to the bottom of open

storm drainage canal intercept/collect sewage and

transport to the wastewater treatment

Sum 439,885 40,000 9 65,983 15 333,902 76 - - 439,885 100

1.2Wastewater treatment plant with surface aerated

basins equipped with electric motorSum 1,029,230 310,000 30 154,385 15 564,845 55 - - 1,029,230 100

1.3Construct new open canal 0. 5km follow the Houay

Longkong stream with erosion protection by rip-rapSum 385,687 115,700 30 46,300 12 223,687 58 - - 385,687 100

1.4Construction of pump house with Installation of

hydrolic pumpsSum 747,000 358,560 48 67,000 9 321,440 43 - - 747,000 100

Total 2,601,802 824,260 32 333,668 13 1,443,874 55 - - 2,601,802 100

II

2.1Reconstruct a drainage structures around Savanxay

Market Sum 537,180 107,000 20 53,718 10 349,000 65 27,462 5 537,180 100

2.2Wastewater treatment plant with series of septic

tanksSum 161,699 21,000 13 27,489 17 113,210 70 - - 161,699 100

Total 698,879 128,000 18 81,207 12 462,210 66 27,462 4 698,879 100

III

3.1

Lining a main sewerage pipes 0.75km following/

parallel the Houay Khilamang to the proposed

wastewater treatment plant

Sum 351,230 80,460 23 37,400 11 218,370 62 15,000 4 351,230 100

3.2 Reconstruct an urban drainage northern side of

Phongnotha Rd connecting to H. Khilamang Sum 413,740 103,435 25 58,000 14 220,000 53 32,305 8 413,740 100

3.3Wastewater treatment plant with surface aerated

basin equipped with electric motorSum 914,589 274,377 30 110,000 12 530,212 58 - - 914,589 100

Total 1,679,559 458,272 27 205,400 12 968,582 58 47,305 3 1,679,559

Total Cost and Percentage Identify 4,980,240 1,410,532 28 620,275 12 2,874,666 58 74,767 2 4,980,240 100

Southern Houay Longkong drainage system subsite

Central drainage system around the Savanxay Market-Chomkeo Stream subsite

Northern Houay Khilamang drainage system subsite

Cost of R. E.

Fac

Total CostCost of Equip

S/No.

Cost of Laybors Cost of Materials

Description of Works Unit Quantity



12.1.3 Estimated Bill of Quantities and project cost estimates

The unit rates and prices quoted in the Bill of Quantities shall include Constructional Plant, equipment, machinery, mobilization, demobilization, appliances, labour, supervision, materials, installation, fittings, fixtures, fabrication, erection, making good defects, maintenance, insurances, site and general overhead charges, profit, freight charges, royalties, import license, fees and levies together with all general risks, liabilities and obligations set forth or implied in the Contract. The unit rates and prices quoted in the Bill of Quantities (BoQ) shall exclude all custom duties and taxes involved in the import of Contractor's plant and equipment, spare parts, goods and materials etc. required for the execution of the works.

The Bill of Quantities are indicative and for feasibility study purposes, they are to be refined on the details engineering designstage. The cost estimates of the project are based on estimated BoQ and on recent level of the rates, prices and exchange rates. Current market prices of construction materials, equipment and skilled/ unskilled labour rates were obtained from local and international commercial establishments, local contractors and previous tendered prices. Based on these rates and prices, the price for each construction activity was developed and presented on the tables bellows:



Table 14: Costs estimate for Southern Houay Longkong drainage System sub-site

GMS Corridor Towns Development Project-Urban Environmental Infrastructure

Kaysone Phomvihane Wastewater Treatment Subproject

Costs estimate for Southern Houay Longkong drainage system Sub-site

Item

No.Description Unit

Estimated

Quantity

Unit price

USDTotal

a b c d e f = (e*d)

BILL No. 1 - GENERAL ITEMS

2.1 Remove the damaged slope section, rehabitate to the existing

form with the material approved by engineer for 2km (incl.

supply and laying of geotextile filter fabric, filling materials and

concrete tiles)

m2 1,200 15.00 18000.00

18,000

3.1 HDPE first 1,300m of 300 mm diameter including the concrete

embedding (upper canal's junction)lin. m 1,300 80 104,000

3.2HDPE the section below the canal's junction 1200m length of

400 mm diameter including the concrete embeddinglin. m 1,200 136 163,200

3.3 Consruct of interceptors sewer on the bottom canal with

chamber boxes as indicated sketch average costs for every

intersecting roads and/or 250m distant

set 15 2,000 30,000

3.4Manholes for maintenance and cleaning every 50m spacing set 28 400 11,200

3.5 Structural excavation of the drainage trenches, along side of

new darainage canal to WWTP about 450mm3 2,300 6.25 14,375

3.6 Structural back fill for the wastewater pipe, along side of new

darainage canal to WWTP about 450mm3 1,900 6.50 12,350

3.7 Provide reinforced concrete manhole complete with cover and

frame (as per drawing ) for pipe line diameters of 400mm:No. 12 430 5,160

3.8 HDPE200 mm diameter connection to main drainage from the

overflow interceptors sewer, siphones and etc., where

applicable

lin.m 250 45 11,250

3.9 HDPE 160 mm diameter connection to collection system lin. m 200 23 4,600

3.10 Embankment fill from selected excavated soil access road

along the wastewater pipe line route where requiring

accessible service road

m3 8,000 4.50 36,000

3.11 Base coarse or surface covering for service road and along the

existing canalm3 3,500 8.50 29,750

421,885

4.1Clearing and grubbing remove top soil to stock pilling for latter

usem2 8,000 0.65 5,200.00

4.2Excavation unsuitable soil to landscping around wastewater

treatment plantm3 1,100 2.25 2,475.00

4.3Common excavation to embankment fill around the wastewater


4.4Common excavation to lanscaping fill around the wastewater


Bill No. 4 - Wastewater treatment plant with surface aerated basin equipped with electric motor

Page Total ( Carried forward to summary )


Bill No. 2 - Improvement of existing lined open canal where damaged

Bill No. 3 - Lining a sewerage pipes 2.5km to the bottom of open storm drainage canal

intercept/collect sewage and transport to the wastewater treatment plant



4.5Construction of embankment fill/dike from the wastewater

treatment pond excavationm3 15,000 2.86 42,900.00

4.6

Construction of embankment fill dike from the borrow materials

and access roads around the wastewater treatment plant and

natural pond

m3 11,000 4.11 45,210.00

4.7 Base coarse for surface covering m3 1,800 12.80 23,040.00

4.8 Local grassing for errosion protection m2 3,750 1.50 5,625.00

4.9

Concrete works including lean concrete, slab, walls, box

culvert and other associated structures, including all

formwork not specified items

4.9.1 Concrete 10Mpa m3 35.00 130.00 4,550.0

4.9.2 Concrete 25Mpa m3 130.00 180.00 23,400.0

4.9.3 Reinforcement steel bars for concrete structures SD40 t 14.00 700.00 9,800.0

4.10 Outlet and inlet structures with regulating gates and etc set 1 23,000 23,000.0

4.11 Stone rip-rap works

4.11.1 Loose rip-rap on embankment slopes for erosion protection size

50-300mm, min thick 500mmm3 6,900 30.00 207,000

4.11.2 Supply and laying of geotextile 3.3KN/50mm under rip-rap

slope protectionm2 13,500 3.00 40,500

4.11.3 Loose rip-rap on the bottom of WWTP pond size 50-300mm,

min thick 500mmm3 8,100 30.00 243,000

4.11.4 Supply and lying of geotextile 3.3KN/50mm under rip-rap for the

bottom of WWTPm2 15,300 3.00 45,900

4.11.5 Construction of scour checks of grouted rip-rap m3 120 136.00 16,320

4.12 Provide a water pond with the wet vegetation for natural

wastewater filterLS 1 20,000.00 20,000

4.13 Electric power connection and lighting installation contract LS 1.00 36,000 36,000

4.14 Provide sewage pump with pump house structure, to lift the

wastewater from the preliminary (sedimmenttation pond) to the

Aerated Wastewater Ponds

LS 1.00 30,000 30,000

4.15 Purchase electric motor with propeller and slinger-ring on

vertical shaft for aeratorLS 1.00 45,000 45,000

4.16 Purchase of sludge pumps LS 1 12,000 12,000

4.17 Boundary fencing with barbed wire ml 850.00 21 17,850

4.18 Tree planting and green area LS 1.00 17,000 17,000

4.19 Simple Administrative building m2 240.00 230.00 55,200.00

1,029,230

5.1 Demolition and clearance

5.1.1 Clearing and grubbing and remove topsoil to spoil area sqm 11,500 0.65 7,475

5.1.2 Demolition and removal of other structures LS 1 10,000.00 10,000

5.1.3 Arrangement for stream diversion during the construction LS 1 6,000.00 6,000

5.2 General Structural excavation

5.2.1 Excavation of unsuitable materials cum 1,200 2.25 2,700

5.2.2 Common excavation to embankment fill and landscaping

around the drainage canalcum 13,000 1.80 23,400

5.2.3 Structural excavation for trenches cum 400 6.25 2,500

5.3 Embankment fill works and access roads

5.3.1 Construct embankment from excavated materials cum 8,500 2.86 24,310

5.3.2 Construct embankment from borrow materials cum 7,723 4.11 31,742

5.3.4 Base coarse for surface covering cum 2,500 12.80 32,000

Local grassing for surface erosion protection cum 6,000 1.50 9,000

Bill No. 5 Construct new open canal 0. 5km follow the Houay Longkong stream with erosion

protection by rip-rap





5.4

Reinforcement concrete works- including lean concrete,

slab, walls and other associated structures and including

all formwork

5.4.1 Lean concrete apply where applicable 10Mpa cum 30.00 130.00 3,900

5.4.2 Mix concrete 25Mpa apply where indicated by the engineer cum 70.00 190.00 13,300

5.4.3 Reinforcement steel bars SD40 for concrete structures t 10.00 700.00 7,000

5.5 STONE RIP RAP

5.5.1

Loose rip-rap for slopes erosion protection of open canal last

section of Houay Lonkong crushed rock 50-300mm Min thick

500mm

cum 5,500 30.00 165,000

5.5.2 Supply and lying of geotextile for canal sqm 10,800 3.00 32,400

5.5.3 Constr. of scour checks, drop structures by grouted rip-rap cum 110 136.00 14,960

Page Total ( Carried forward to summary ) 385,687

6 Bill No. 6 - Construction of pump house with Installation of hydrolic pumps

6.1 Installation of Pump 1800 m3/hour & Control panel set 2 120,000 240,000

6.2 Construction of Pump house (Dimension 8x8m) m2 64 500 32,000

6.3 Electricity installation - Connection

6.3.1 Transformer 250 KVA with control panel & Control board set 1.00 15,000.0 15,000.00

6.3.2 Concrete electric pole 12 m high pce 2.00 200.00 400.00

6.3.3 Electric cable from source to transformer, dia 4 x 95 m 200.00 25.00 5,000.00

6.3.3 Electric equipment with cable NYY 4 x 70, L=30m set 1.00 2,800.00 2,800.00

6.4

Reconstruction/extension of existing convert including

lean concrete, foundation, slab, walls and other

associated structures and incl. all formwork

6.4.1 Concrete 10Mpa m3 15.00 100.00 1,500.0

6.4.2 Concrete 25Mpa m3 190.00 180.00 34,200.0

6.4.3 Reinforcement steel for concrete structures SD40 t 24.00 700.00 16,800.0

6.4.4 Steel profiles t 10.00 700.00 7,000.0

6.4.5 Sliding gates with mechanical lifting winch set 2 27,000 54,000.0

6.4.6 Flab gates set 2 14,000 28,000

6.4.7 Preparation for erosion protection the Houay Longkong outlet sum 1 10,000 10,000

6.4.8Rip-rap for erosion protection around and outlet to Mekong for

about 140m- D50-300mm and D400-600mmcum 8,470 30.00 254,100

6.4.9 Supply and laying of geotextile for general sqm 15,400 3.00 46,200

Page Total ( Carried forward to summary ) 747,000.00

Total Cost for Construction of Package A Bill No.2-Bill No.6 2,601,802

Sub-total Direct Cost(I) 2,601,802

II Indirect costs

Detailed engineering design 5% 130,090

Construction supervision 3% 78,054

Physical Contingency 10% 260,180

Price Contingency 15% 390,270

Sub-total in direct cost(II) 858,595

Grant total I and II 3,460,396



Table 15: Costs estimate for Central drainage system around the Savanxay Market sub-site



2.4.7DHPE200 mm diameter connection to gulleys,

catch basins, manholes, culverts, and outfallslin. m 457 40 18,280

2.4.8 RC Chamber for sullages Connection No. 163 50 8,150

2.5

Reinfoercement concrete works provisional

item-including lean concrete, slab, walls and

other associated structures, including all

formwork and labor

2.5.1 Lean Concrete 10Mpa cum 15.00 80.00 1,200

2.5.2Concrete class 20Mpa will be applied where

requirecum 120.00 160.00 19,200

2.5.3 Reinfoercement steel bars SD40 for concrete t 13.00 700.00 9,100

2.5.4 Provide geotextile for general use m2 900.0 3.00 2,700

537,180


3.1.1 Clearing and grubbing and remove topsoil to

spoil areasqm 500 0.65 325

3.1.2 Demolition and removal of other structures and

existing drainage canal to spoil areaLS 1 4,000.00 4,000

3.1.3 Arrangement for diversion of existing sewage

during the constructionLS 1 1,000.00 1,000

3.1.4 Removal of underground abstruction if any

(include water supply and reinstallation)LS 1 2,000.00 2,000


3.2.1 Excavation of unsuitable materials to spoil area cum 280 4.25 1,190

3.2.2 Strutural excavation for trenches to stock pilling

for latter usecum 1,600 6.25 10,000

3.3 Back fill and embedding works

3.3.1 Compacted road base coarse material

underseptic tanks 0.4cm thickcum 210 17.00 3,570

3.3.2 Back fill with materials from borrow area cum 251 8.50 2,134

3.3.3Base coarse for surface covering the area for

accessiblecum 550 12.80 7,040

3.3.4 Local grassing for surface erosion protection cum 400 1.50 600

3.4

3.4.1 Lean concrete 10MPa cum 34 100.00 3,400

3.4.2 Reforced conrete for bottom, top slabs, wall and

etc., associated with septic thans 25MPacum 270 220.00 59,400

3.4.3 Reinforcement steel bars SD40 for concrete

structures and steel wire t 28 700.00 19,600

3.4.4 Rip-rap errosion protection size 400-600mm cum 640.00 30 19,200

3.4.5 Grouted rip-rap for errosion protection outlet cum 140.00 136 19,040

3.4.6 HDPE 200 mm diameter connection

interceptors sewer and paeces tankslin. m 120 45 5,400

Bill No. 3 - Wastewater treatment plant with series of septic tanks


Construct of series wastewater treatment plants kind of septic tanks as the land

available Reinfoercement concrete works- including lean concrete, slab, walls and

other associated structures and formwork inclusive




3.4.7 HDPE 70-100 mm diameter for various connection in systemlin. m 100 13 1,300

3.4.8 Miscellaneous (broken brick, washed gravel, charcoal)sum 1 2,500 2,500

3.4.9 Construct an overflow interceptors sewer sum 1 1,300.00 1,300

Page Total ( Carried forward to summary ) 161,699

Total Cost for Construction of Package B Bill No.2-Bill No.3 698,878.50

Sub-total Direct Cost(I) 698,878.50

II Indirect costs






Grant total I and II 929,508



Table 16: Costs estimate for Northern Houay Khilamang drainage system sub-site





4.1.1 Clearing and grubbing and remove topsoil to spoil area sqm 5,000 0.65 3,250

4.1.2

Demolition and removal of other structures and existing

drainage canal to spoil area as (underground pits, chambers,

cesspools, and similar facilities include water supply and

reinstallation)

ml 1,130 25.00 28,250

4.1.3 Arrangement for diversion of existing sewage during the

constructionLS 1 4,000.00 4,000


4.2.1 Excavation of unsuitable materials to spoil area cum 800 4.25 3,400

4.2.2 Strutural excavation for trenches to stock pilling for latter use cum 2,700 6.25 16,875

4.3 Back fill and embedding works

4.3.1Compacted road base coarse material and sand under

drainage pipe 15cm thickcum 520 17.00 8,840

4.3.2 Back fill with materials from borrow area or sand filling cum 3,750 8.50 31,875

4.3.3 Base coarse for surface covering cum 1,250 12.80 16,000

4.3.4 Local grassing for surface erosion protection cum 5,000 1.50 7,500

4.4 Drainage installation

4.4.1

Pipes drainage (Type-B),1000 mm diameter below ground

surface with average depth 2-2.5m: bedding, Lean concrete,

Joint but not incl. earth works

lin. m 1,130 163 184,190

4.4.2

Pipes Culvert (Type-A),1000 mm diameter below Road

Crossing (4 spots) with excavation, bedding, Lean concrete,

Joint and Back filling

lin. m 44 185 8,140

4.4.3

Provide reinforced concrete manhole complete with cover and

frame (As per drawing )for pipe diameters up to and including

1000mm, with spacing 30m

No. 38 495 18,810

4.4.4

Provide reinforced concrete T manhole complete with cover

and frame (As per drawing ) for pipe diameters up to and

including 1000mm:

No. 3 460 1,380

4.4.5Provide catch basin complete with frame and grating (as per

Drawing)No. 34 425 14,450

4.4.6 DHPE 100 mm diameter connection to collection system lin. m 360 18 6,480

4.4.7 DHPE200 mm diameter connection to gulleys, catch basins, lin. m 340 40 13,600

4.4.8 RC Chamber for sullages Connection No. 102 50 5,100

4.4.9

Intercepter sewer structure at the end of urban drainage

culvert(storm drainage) and arrange for connecting to the

main wastewater pipe line

No. 1 4,000 4,000

4.5

4.5.1 Lean Concrete 10Mpa cum 15.00 80.00 1,200

4.5.2 Concrete class 20Mpa will be applied where require cum 120.00 160.00 19,200

4.5.3 Reinfoercement steel bars SD40 for concrete structures t 15.00 700.00 10,500

4.5.4 Provide geotextile for general use m2 900.0 3.00 2,700

4.5.5 Outlet/drop structure at the outlet of drainage pipe LS 1 4,000.00 4,000

413,740

Bill No. 4 - Reconstruct an urban drainage northern side of Phongnotha Rd connecting to H.

Khilamang (Pipes Culverts, Manholes, Gutters and Chamber etc.)


Reinfoercement concrete works provisional item-including lean concrete, slab, walls and other

associated structures, including all formwork and labor




5.1 Clearing and grubbing remove top soil to stock pilling for

latter usem2 20,000 0.65 13,000.00

5.2 Excavation unsuitable soil to landscping around wastewater


5.3 Common excavation to embankment fill around the

wastewater treatment plantm3 16,000 1.80 28,800.00

5.4 Common excavation to lanscping fill around the wastewater


5.5 Construction of embankment fill/dike from the wastewater

treatment pond excavationm3 14,500 2.86 41,470.00

5.6 Construction of embankment fill dike from the borrow

materials and access roads around the wastewater

treatment plant and natural pond

m3 4,400 4.11 18,084.00

5.7 Base coarse for surface covering m3 1,600 12.80 20,480.00

5.8 Local grassing for errosion protection m2 3,750 1.50 5,625.00

5.9

Concrete works including lean concrete, slab, walls

and other associated structures and including all

formwork

5.9.1 Concrete 10Mpa m3 30.00 130.00 3,900.0

5.9.2 Concrete 25Mpa m3 120.00 180.00 21,600.0

5.9.3 Reinforcement steel bars for concrete structures SD40 t 14.00 700.00 9,800.0

5.10 Outlet and inlet structures with regulating gates and etc set 1 16,000 16,000.0

5.11 Stone rip-rap works

5.11.1 Loose rip-rap on embankment slopes for erosion protection

crushed rock 50-300mm, min thick 500mmm3 6,500 30.00 195,000

5.11.2 Supply and lying of geotextile 3.3KN/50mm for emb.slopes m2 10,300 3.00 30,900

5.11.3 Construction of scour checks of grouted rip-rap m3 170 136.00 23,120

5.11.4 Loose rip-rap on bottom of WWTP, crushed rock 50-300mm,

min thick of 500mmm3 6,500 30.00 195,000

5.11.5 Supply and lying of geotextile 3.3KN/50mm m2 11,500 3.00 34,500

5.12Construct a water pond with the sellected natural vegetation

wastewater filterLS 1 28,000.00 28,000

5.13 Electric power connection and installation, lightings contract LS 1 40,000 40,000

5.13

Provide sewage pump with pump house structure, to lift the

wastewater from the preliminary/sedimmenttation pond to the

Aerated Wastewater treatment ponds

LS 1 30,000 30,000

5.14 Purchase electric motor with propeller and slinger-ring on

vertical shaft for aeratorLS 1 45,000 45,000

5.15 Purchase of sludge pumps LS 1 12,000 12,000

5.16 Area fencing with barbed wire ml 860.00 21 18,060

5.17 Tree planting and green area LS 1.00 16,000 16,000

5.18 Simple Administrative building m2 240.00 230.00 55,200.00

914,589.0

Total Cost for Construction of Package C Bill No.2-Bill No.4 1,679,559

Sub-total Direct Cost(I) 1,679,559

II Indirect costs






Grant total I and II 2,233,813

Bill No. 5 - Wastewater treatment plant with surface aerated basin equipped with electric motor




The total investment cost of the wastewater treatment subproject amounts to $4.94 million, representing the direct cost for the civil works for drainage canals, sewerage pipelines and the WWTP. In addition, $1.65 million in indirect costs, adding up to a total of $ 6.62 million.

12.2 Operational and maintenance costs

12.2.1 Operations and Maintenance manuals

The contractor and his suppliers shall be required to provide an Operations and Maintenance Manual covering the following topics:

• detailed descriptions of all operating processes • detailed data for all equipment, components and systems • pump and system head curves showing the design operating points incl.

drainage pumps for flood control • startup and shutdown procedures • analysis of critical safety issues • inventory of critical components, including name plate data for pumps, motors,

and the like • description of the maintenance management system and process including

preventive • and predictive maintenance • risk analysis • contingency plan, including redundancy considerations • list of affected agencies and utilities, local contractors, and vendors including

after hour contacts • staff training plan.

12.2.2 Operational and maintenance costs estimates

After the completion of the Kaysone Phomvihane Wastewater Treatments subproject,it is proposed to establish the O&M unit under UDAA that will be responsible for the management of the system and to maintain its normal operational procedure. The O&M budget and cost estimates are shown in Table 17.



Table 17 : Costs estimates for operational and maintenance wastewater management system.

Source:GMS Corridor Towns Development Project. (TA 7644-REG)

item Description Unit QuantityUnit price,

US$

total (US$),

per yearRemarks

1

Operational costs for the truck with the

complete maintenance tools for the drainage

system and wastewater management

purchased by the project

Per-

month12 100 1200

Capital value

truck with tools

40000$, 5 years

has included in

investment cap.

2

Hiring Vacuums Cleaner Truck with Pump

when needed for maintenance and cleaning,

otherwise hiring for regular manternance 10

days an month, 70$*10days

Per-

month12 700 8400

rate 60$/day fuel

included

3Electricity for Aeratation WWTPs, 3W/cum,

10,756 cum/day equivalent 40kWh per month

kwh/per

month12.00 25 300.00

5$ per according

to guide line

4

Staff salaries: 1 foreman, 1 mechanic, 1

electric, 4 skill labors and 3 administrative, 12

security guards, 2 grass cutting

per month 12 6,390 76,680.00

5Electric bills for lighting, various use in normal

operation, adm. Office, pumps, workshop

Per-

month12 700 8,400.00

6

Electricity for drainage pump, about 28days

a year in August-September, 120KW*2units

*24h=>5760kWh a day

Per-day 30 552.96 16588.8

Assume only 4

weeks a year

floods

7 Others spare parts and consumale 11,156.8810% of the sum

of all above cost

8 Contingency 17,274.00

total 140,000



7 PROJECT MANAGEMENT

12.1 Subproject implementation

The Project Management Unit (PMU) which will be established in the Province of Savannkhet‟s Provincial Department of Public Works and Transport (PDPWT) will ensure that the implementation of all civil works and construction activities related to the Kaysone Phomvihane Wastewater Treatment subproject strictly comply with relevant national and local issuances and regulations during the course of subproject implementation. The PMU through the Project Implementation Team (PIT) will regularly monitor the compliance of the subproject implementation in relation to ADB guidelines and agreed work plans and schedule of activities.

The implementation of the Kaysone Phomvihane Wastewater Treatment subproject will be undertaken during the project period of 6 years, from 2013 to 2018. Detailed engineering design and construction supervision will be carried out during 2013. Civil works and construction activities are expected to commence during 2015.

The WWT subproject implementation arrangements will involve three phases as follows:

a) Detailed Engineering Design comprising:

• preparation of designs and drawings • engineering surveys and geotechnical investigation • preparation of tender specifications and technical documentation • preparation of tender commercial documentation • preparation of prequalification documentation • preparation of design and other specified reports.

b) Procurement and bidding procedures:

• assistance with advertising and prequalification of bidders • assistance with invitations to tender • assistance during the tender period • assistance during negotiation and award of contracts.

c) Construction Supervision

• co-ordination of project works • overall works project management • administration and supervision of construction, commissioning and hand over of

the completed works to the owner • preparation of completion report.

The PMU shall ensure that the implementation of these activities are carried out in a cost effective and time efficient manner.

12.2 Implementation Schedule

The overall construction implementation program is shown in Figure 19 and comprises the overall design, tendering and construction program for the Kaysone Phomvihane Wastewater Treatment project contract.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84

Construction civil works

8

9

3

4

5

6

Test run

Erection/installation of

equipment

10

11

7

Procurement of

equipment

Construction supervision

PMS concultancy. PQ

and Selection of DED

and construction

supervision consultants

Additional surveys

Detailed engineering

design incl. tender

documents

Loan agreement process

Prequalification and

Tendering process

1

2017 2018

Loan Efficiency2

2012 2013 2014 20162015

Testing & Commissioning

Figure 19: overall implementation schedules




12.3 Procurement arrangements and packages

The procurement of works, goods and services for the Kaysone Phomvihane Wastewater Treatment subproject will be undertaken in compliance with the national procedures and in accordance with ADB procurement guidelines. Given the nature of the subproject, the procurement arrangements will involve 2 contract packages; one for consulting services for detailed engineering design (DED) and construction supervision and another for civil works. The procurement for DED will be done through quality and cost-based system (QCBS) while it will be international competitive bidding (ICB) for civil works.

Table18. Procurement Method for Kaysone Phomvihane Wastewater Treatment

No. Contract Package Cost estimate

(USD) Procure method

Estimated duration (month)

1 Contract 1 – DED and Construction supervision 398,419.00 QCBs 50

2 Contract 2 – Civil works for construction of drainage networks and sewage pipelines and establishment of 3 wastewater treatment facilities

4,980,239.00

ICB

42

Source: GMS Corridor Towns Development Project (TA 7644-REG)

12.4 Monitoring requirements and arrangements

The monitoring of the civil works and construction activities shall be undertaken by the PMU based on the approved work plan and schedules. The PMU will adapt the Project Performance Monitoring System (PPMS) to track and validate the physical and financial progress of subproject implementation including the status reports submitted by the contractor. Regular monitoring of subproject implementation will be complemented by site visits and ocular inspection, field discussions and key informants interviews.

The PMU will coordinate the monitoring activities with the Project Implementation Team in Kaysone Phomvihane and with the District Authority on the conduct of joint inspection and field validation during the course of subproject implementation. The PMU will prepare and submit regular progress reports to the implementing agency, the PDPWT in Savannahket and to the Executing Agency which is the MPWT. Regular progress reports will also be transmitted to the Provincial Government of Savannahket.

After physical completion of the civil works and construction activities, the monitoring of the road and drainage conditions including the status of related facilities will be handed over by the PMU to the PDPWT. Regular field inspection will be jointly undertaken by the District Office of PWT and UDAA and regular progress reports will be submitted to PDPWT and the Provincial Government of Savannahket.

Operational monitoring

Strictly follow the operational and maintenance manual formulated after the project completion by the contractor or suppliers for each structure and equipment;

Monitoring of maintenance routines and check lists;

Frequent monitoring and maintenance of transport system clogging (with litter, branches, earth);

Frequent analysing and reporting and adjustment in workloads etc.;



Control the performance of each unit and the responsibility for every section;

Overall inspection, checking of workable conditions for the system and plants, especially during the wet season to avoid any part of the system out of services;

Control of the reserve of spare parts, resources for immediately action if any part of system broken down;

Worked out the mechanism and control how to have payment for the system being services; and

Carry out routine test of functioning the electrical control boxes of pumping station. Environmental monitoring Wastewater collection, transport and disposal

Undertake visual observations and reporting on conditions of released wastewater of each Wastewater Treatment (through random visits);

Taking control and monitoring samples and making lab analysis;

Wastewater Treatment

Visual control of surround water pollution and seepage from the wastewater treatment lagoon;

Monitoring of proper maintenance electrical equipment pumps

Strict control system to avoid transmission pipe line out of services




Table 19: Indicative Composition of the PMU Management and Staff

Position Number Status Remarks

PMU Project Director 1 Designated

By MPWT

Project Coordinator 1 Designated

By MPWT

Urban Road/Civil Engineer 1 Designated

By PDPWT

Flood Control and Drainage 1 Designated

By PDPWT

Social and Environment Officers 2 Designated

By PDPWT

Urban Development Planner 1 Designated

By PDPWT

Administrative and Finance Officers 2 Designated and/or hire

By PDPWT

Administrative Support Staff 2

Designated and/or hire By PDPWT

12.4.2 Arrangements for Subproject Implementation

In Kaysone Phomvihane, the PMU will organize the Project Implementation Team (PIT) responsible for overseeing the day-to-day coordination of subproject implementation. The PITshall be manned by technical and administrative staff from the District Office of Public Works and Transport and the UDAA of Kaysone Phomvihane.

The specific role and responsibilities of the PIT will be as follows:

i) Conduct briefings and orientation programs on the Kaysone Phomvihane Wastewater Treatment subproject for Project stakeholders,

ii) Coordinate the work plans and program of activities of the PMS consultants,

iii) Monitor the progress of civil works and construction activities through field validation and site inspection,

iv) Coordinate the implementation of social and environmental safeguards and resettlement plans including capacity development program activities in the corridor town.

v) Prepare and submit regular physical progress reports to the PMU.

vi) Coordinate the active involvement of provincial and local agencies and institutions to ensure broad participation in Project related activities and to further enhance the sense of ownership.

vii) Conduct follow through consultation meetings and trainings/workshops with Project stakeholders and participating government agencies and private sector groups on critical issues and concerns related to subproject implementation.

The PITshall be headed by a Project Coordinator designated by the Implementing Agency in close consultation with the PMU. The Project Coordinator shall be designated on the basis of technical qualifications and experience relevant to the CTDP. The members of



the PIT will also designate technical and administrative staff from the District Office of PWT and UDAA. Aside from the designated personnel, the PIT may recruit administrative support staff to assist the Project Coordinator on finance and administrative matters. The PIT will be assisted by the PMS Consultants in undertaking the capacity building programs in Kaysone Phomvihane.

During the course of subproject implementation, the PIT will closely coordinate with participating agencies and institutions to ensure proper complementation of coordination and monitoring activities. Regular consultative meetings shall be organized by the PIT with Project Stakeholders to discuss the status of subproject implementation, issues and concerns arising during the course of project operation, courses of remedial actions and delineation of roles and responsibilities to ensure achievement of the project objectives. The PIT will also hold regular dialogues and meetings on matters related to capacity building needs assessment, conduct of training programs and monitoring of the impact of capacity building interventions at the local level.

The funding requirements for operation and management of the PMU and the PITshall be sourced out from the budgetary allocation of the IA and fund contributions from the Provincial Government of Savannahket and the District Authority of Kaysone Phomvihane.



Table 20: Composition of the PIT Management and Staff, Kaysone Phomvihane

Position Number Status Remarks

PIT Manager 1 Designated By PMU Director

Project Coordinator 1 Designated By Municipal PWT/UDAA

Civil Engineer/Wastewater Engineer

1 Designated By Municipal PWT

Project Monitoring Officer 1 Designated By Municipal PWT/UDAA

Social and Environment Officer 1 Designated By Municipal PWT

Administrative and Finance Officers

2 Designated By Municipal PWT/UDAA

Administrative Support Staff 2 Designated and/or hire

By Municipal PWT


The organization and management structure of the PMU and PIT in Kaysone Phomvihane is presented in the following figure.



Figure 19: Structure of Subproject Implementation and Management Source: GMS Corridor Towns Development Project. (TA 7644-REG)

Project Management Unit (PMU)

(Project Director)

MPWT (Executing Agency)

PDPWT

(Implementing Agency)

DOPWT

(Field Implementing Unit)

Project Implementation Team (PIT)

Head of PIT

(Project Coordinator)

contractors, suppliers,

service providers

Project Management

Support

Consultant

Kaysone Phomvihane

District, UDAA

(Field Implementing Unit)

Project Coordinator for

Technical Services

Administration Support Staff

Social -Environmental

Safeguards Staff

Project Monitoring and

Evaluation Group

Technical Services

Section Financial and

Administration Section

Road/Highway Engineer

Drainages Structure Engineer

Disbursement Officer

Finance Officer

Procurement and Contract Management Office

Administration Staff

Civil Engineer

Social and Environment Safeguards Officers



In order to ensure effective management and operation, the PMU and PITshall be provided with necessary office equipment and facilities. The list of office equipment shall be developed by the PMU in consultation with the PMS consultant.

a. Subproject consultation with Stakeholders

The PMU and PIT will jointly conduct regular consultation meetings and workshops on public awareness program for the Kaysone Phomvihane Wastewater Treatment subproject with District Authority and village cluster committees. During the subproject implementation, consultation meetings are to be conducted with provincial, district line agencies to discuss the project status and to address implementation concerns including the capacity building programs. Coordination arrangements will be undertaken with the Provincial Government of Savannahket and the District Authority of Kaysone Phomvihane in the preparation and implementation of the budgetary plans for subproject operation and maintenance to ensure long term sustainability of the Kaysone Phomvihane Wastewater subproject.

b. Institutional capacity building

As an integral component of institutional strengthening, selected personnel and staff from the PDPWT, DOPWT and from District Authority of Kaysone Phomvihane will be provided capacity building assistance through their participation in workshops, seminars and training programs on strategic local economic development and investment planning, subproject feasibility study preparation and capacity development planning. The PMU and PIT staff will be provided technical assistance and advisory services in subproject implementation and management through a series of on-the-job training programs, group dynamic sessions and technical workshops. The PMS consultant in close coordination with the PMU will develop a district-wide wastewater management plan drawing lessons and experience from the implementation of the Kaysone Phomvihane Wastewater Treatment subproject and through the consultation and participation approach that has been adapted by the Project.

8.1.3 Subproject Operation and Maintenance Arrangements

During the course of Kaysone Phomvihane subproject implementation, the PMU will coordinate with the PDPWT and the UDAA of Kaysone Phomvihane the requirements and procedures for proper operation and maintenance (O&M) arrangements. These arrangementsshall be based on the Subproject Operation and Maintenance Manual that will be prepared by the PMS Consultants. A series of workshop seminars and on-the-job training sessions on O&M shall be conducted by the PMU and the PMS Consultants for the technical and administrative personnel of the PDPWT and the UDAA. These capacity building interventions will commence prior to the completion of the civil works and construction activities and is intended to prepare the PDPWT and UDAA for the turn-over of the O&M arrangements for the Kaysone Phomvihane Wastewater Treatment subproject.

The PMS consultant will also conduct a series of workshops and follow-through activities on the preparation of the operation and maintenance plan which will include the required activities and the specific roles and responsibilities for continuing operation and maintenance of the subproject. The plan also includes the indicative cost and the sources of funds for the operation and maintenance activities.

The PMS consultant will develop a maintenance program that optimizes the subproject costs and maximizes the use of equipment in a time efficient manner. For a maintenance program to be effective, selected technical and administrative staff of PDPWT, DOPWT and UDAA shall be mentored on general understanding of the relationship between their operating plans and priorities, the skill level of operating and maintenance personnel and types of equipment and materials for proper operation of the equipment. The PMS will conduct hands-on training sessions to ensure the implementation of a well planned



maintenance program that will result in the long term sustainability of the Kaysone Phomvihane Wastewater subproject.

Figure 20: Kaysone WastewaterSubproject Operation and Maintenance Arrangements


Upon completion of the civil works and construction activities, the PMU will hand over the Kaysone Phomvihane Wastewater Treatment subproject to PDPWT which will undertake the regular for operation and maintenance activities in close coordination with UDAA .The PDPWT will also allocate the necessary O&M budget which will be complemented by fund contribution from the UDAA. The hand over will include the Subproject Operation and Maintenance Manual and the Operation and Maintenance Plan developed by the PMU with the technical assistance of the PMS Consultant.

As the designated implementing agency, the PDPWT will include the Kaysone Phomvihane Wastewater subproject under its regular monitoring programs and progress reporting system. The subproject will be part of the field validation and site inspection visits to be undertaken by monitoring officers from the MPWT on a regular basis.The PMU and PIT will jointly undertake public awareness and social marketing programs that are intended to inform the general public of the Kaysone Phomvihane Wastewater Subproject and encourage broad base participation in monitoring the progress of subproject implementation.

The budgetary requirements for the operation and maintenance of the subproject will be included in the national budget allocation to the PDPWT and the provincial budget allocation to the District Office of PWT. The Provincial Government of Savannahket and the District Authority of Kaysone Phomvihane will provide counterpart contribution for capacity building and training programs related to subproject implementation, operation and maintenance.

Project Management

Unit (PMU)

Project

Implementation Support

Consultant

Project Implementation Team (PIT)

Head of PIT

Contractors, Suppliers, Service

Providers

Savannakhet

DPWT

Savannakhet

Provincial

Governor

PWT

District

Office

Kaysone Phomvihane District,

UDAA



8.2 Financial Feasibility

Financial feasibility determines the return on investment of the subproject, financial capacity of the entity to implement the subproject, cost recovery options and affordability of user fees and charges to beneficiaries.

8.2.1 Financial Evaluation Approach

This section presents an evaluation of the financial viability of implementing the proposed wastewater treatment plant for the town of Kaysone Phomvihane under CTDP. The approach to the financial analysis follows the guidelines for the financial analysis of projects described in ADB‟s Financial Management and Analysis of Project (2005). Two basic indicators for the financial viability of the wastewater treatment plant subproject have been identified. These are the following:

Financial Internal Rate of Return (FIRR). It is the discount rate at which the net revenues generated by the project are equal to zero. A project is considered financially viable if the computed FIRR is at least equal to the weighted average cost of capital (WACC) that is used in financing the development of the proposed water supply subproject.

Tariff affordability. Minimum fee or charge should be within the affordability of the average monthly income of the low income group.

8.2.2 Cost Analysis

The Kaysone PhomvihaneWastewater Treatment Subproject will involve the improvement of existing storm water drains, construction of sewerage interceptor pipelines and the installation of new wastewater treatment plants in 3 separate areas. It includes the following major components: civil works for the improvement of existing storm water drainage networks along the river streams in the northern, central and southern portion of the town center; installation of sewage interceptor pipelines at the bottom of the storm water drains; extension of sewage interceptor pipelines to the site of the wastewater treatment plant; installation of drainage pumps as flood control measures; and establishment of 3 new wastewater treatment plants in the northern, central and southern locations.

The basic investment cost of the proposed subproject and the operating and maintenance costs are prepared on an annual basis for the purpose of the financial analysis. These costs are estimated in 2011 prices. Increases in costs due to inflation rates are covered through a provision of price contingencies for the capital costs and relevant inflation factor for O&M costs.

Development Costs.The total development cost for the subproject is approximately $7.93 million. This is based on the cost presented in the technical study with total direct cost of $6.12 million for the three sites. Costs for detailed engineering design, construction supervision and physical contingency were added. An additional price contingency was likewise added to allow for the timing of implementation, both for local and foreign cost components.

The project is scheduled to start implementation by the beginning of 2014 and is targeted to be completed by 2018, such that full operation of the project will be by 2019. Acquisition of land required for the project and conduct of detailed engineering design, however, has to be done in the first semester of 2014 prior to construction works.

Financing Scheme. The subproject will be financed through lending from Asian Development Fund (ADF). ADF loan will finance $6.18 million or 78% of the total subproject. The government will finance the remaining cost which is composed of resettlement and taxes for the components. The investment and financing plan is shown in Table 21.



Table 21:Total Investment and Financing Plan ($million)

Total Fund Source

Cost ADF Government

Direct Costs

Southern 1.78 1.62 0.16

Central 1.98 1.80 0.18

Northern 1.22 1.11 0.11

Resettlement 1.14 0.00 1.14

Subtotal 6.12 4.53 1.59

Indirect Costs

Detailed Engineering Design 0.25 0.23 0.02

Construction Supervision 0.15 0.14 0.01

Physical Contingency 0.50 0.45 0.05

Price Contingency 0.92 0.83 0.08

Subtotal 1.81 1.65 0.16

Total Costs 7.93 6.18 1.76

78% 22%


Operating and Maintenance Costs.

Without the Project O&M. For the computation of subproject viability, incremental costs as a result of the subproject are used in the evaluation. Projections for both the “without project” and “with project” situation are usually done to derive the incremental costs. However, since there is currently minimal or no O&M, it is assumed to be zero for the purpose of financial evaluation. Thus, the analysis considers the subproject as an entirely new facility.

With the Project O&M. Operating and maintenance costs were derived from the technical study. It includes the repair and maintenance of the structures, wastewater pipeline network, and wastewater treatment plant including the pump stations. From the technical study, annual O&M expense is estimated to be about $0.14 million annually.

8.2.3 Revenue Forecasts

Revenue is estimated from the wastewater fee that can possibly be collected from the beneficiaries. Estimates of annual revenues are based on the total estimated volume of wastewater that will be treated and the corresponding fee for each unit, say LAK per cubic meter of wastewater.

Existing Fee. (Without the Project). Significantly, the UDAA is collecting wastewater fee even if there is no efficient system in place. Households connected to the water system are collected a fee of LAK 2,000 per household per month. There is no information however on



how many households are paying the fee on a timely manner. It is assumed that unless a good system is put in place, the government cannot collect any fee related to this subproject.

Proposed Fee. (With the Project).The base assumption for the proposed fee is based on the computed average incremental financial cost (AIFC) of $15 per m3. The cost per family per month is $2.70. The proposed fee is expected to cover fully the investment and operations and maintenance costs. However, partial cost recovery is a more realistic assumption given the fact that people‟s affordability to pay is way below this amount.

Strategies in fee collection maybe employed to ensure a more equitable fee structure. Some level of cross-subsidy maybe implemented wherein the business sector would pay a higher rate as compared to the residential connections. Another strategy is to implement partial recovery with the government providing subsidy on its initial years of operation and aiming for full recovery in the later years.

Detailed computation of fee is presented in the following table:

Table 22:Cost Recovery Schemes

Partial Cost Recovery Full Cost

Investment O&M Recovery

AIFC ($) 0.060 0.090 0.150

Wastewater generation (lpcd) 120.000 120.000 120.000

Cost per person per day ($) 0.008 0.010 0.018

Cost per family per day ($) 0.040 0.050 0.09

Cost per family per month ($) 1.130 1.570 2.700


8.2.3 Project Viability

Financial Internal Rate of Return (FIRR). One of the more accepted financial viability indicators for development projects is the FIRR. A subproject is considered financially viable if the resulting FIRR of the proposed subproject is higher than the weighted average cost of capital (WACC) that was used in financing the subproject. An FIRR higher than the WACC implies that the incremental net revenues generated by the project will be enough to recover the implementation and operating costs.

On the basis of the financing mix and the loan interest of 1.5% and the assumed cost of equity of 2%, the WACC is computed to be about 1.49%. Table 23 shows the computation of the WACC.



Table 23:Computation of Weighted Cost of Capital (WACC)

Financing Component

ADF Govt Total

A. Amount (Php'000) 6.18 1.76 7.93

B. Weighing

77.8% 22.2% 100.0%

C. Nominal cost

1.5% 2.0% D. Tax Rate

10.0% 0.0% E. Tax-adjusted nominal cost

1.4% 2.0% F. Inflation rate

G. Real cost

1.4% 2.0% H. Weighted component of WACC

1.1% 0.4% 1.5%

Weighted Average Cost of Capital (Real) 1.49% Source: GMS Corridor Towns Development Project. (TA 7644-REG)

Result of financial evaluation shows that the subproject is viable with an FIRR of 4.29% and NPV of $2.97 million. Sensitivity analyses are likewise conducted to determine the effects of adverse changes on a project such as delay in operation, revenues not realized as expected or increase in capital and O & M costs. The scenarios evaluated and the summary results of the analyses are presented in Table 24. The results show that the subproject is viable under the five scenarios evaluated.

Table 24: Result of Financial Internal Rate of Return and Net Present Value


Year Project Incremental Revenues Net Sensitivity Analysis

Cost O&M Cost Flows Cost (+10%) Ben (-10%) Cost (+10%) Revenues

Ben (-10%) Delayed by

One Year

2013 0.25 - - (0.25) -0.27 -0.25 -0.27 -0.25

2014 1.69 - - (1.69) -1.86 -1.69 -1.86 -1.69

2015 2.03 - - (2.03) -2.23 -2.03 -2.23 -2.03

2016 2.03 - (2.03) -2.23 -2.03 -2.23 -2.03

2017 1.02 (1.02) -1.12 -1.02 -1.12 -1.02

2018 - 0.14 0.63 0.49 0.48 0.43 0.42 -0.14

2019 - 0.14 0.64 0.50 0.49 0.44 0.43 0.49

2020 - 0.14 0.66 0.52 0.50 0.45 0.44 0.50

2021 - 0.14 0.67 0.53 0.52 0.46 0.45 0.52

2022 - 0.14 0.68 0.54 0.53 0.48 0.46 0.53

2023 - 0.14 0.70 0.56 0.54 0.49 0.47 0.54

2024 - 0.14 0.71 0.57 0.56 0.50 0.49 0.56

2025 - 0.14 0.73 0.59 0.57 0.51 0.50 0.57

2026 - 0.14 0.74 0.60 0.59 0.53 0.51 0.59

2027 1.41 0.14 0.76 (0.79) -0.95 -0.87 -1.02 -0.81

2028 - 0.14 0.77 0.63 0.62 0.55 0.54 0.62

2029 - 0.14 0.79 0.65 0.63 0.57 0.55 0.63

2030 - 0.14 0.80 0.66 0.65 0.58 0.57 0.65

2031 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2032 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2033 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2034 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2035 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2036 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2037 1.41 0.14 0.80 (0.75) -0.90 -0.83 -0.98 -0.75

2038 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2039 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2040 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2041 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

2042 - 0.14 0.80 0.66 0.65 0.58 0.57 0.66

Total 9.84

Financial Internal Rate of Return 4.29% 3.14% 3.01% 1.85% 3.53%

Net Present Value 2.97 1.82 1.52 0.37 2.25



8.2.4 Affordability of wastewater Rates

A major consideration in the development of any service fee schedule is the ability of target beneficiaries to pay for their monthly bill. It is a standing policy of ADB and other foreign funding institutions that the minimum charge for water supply for residential beneficiaries should not exceed 5% of the family income of the low income group among families connected to the system. This maybe considered for municipal utilities as a whole, and wastewater alone should not exceed 1.5-2% of the family income of the low income group.

For this study, classification of households according to socio-economic status was done based on the result of the socio-economic survey conducted as part of this study. Per capita thresholds such that those that fall below the poverty threshold are categorized as poor and conversely, those above the threshold level are considered non-poor. To be able to evaluate the affordability of the proposed wastewater fee to the low income group, the estimated 2011 income level was adjusted to 2016 level by assuming an annual increase of 5% per annum.

Based on the socio-economic survey results, the current average monthly income is LAK 2,980,194 for the average income household group while for the low income household, it is LAK 1,287,317. These are projected to increase in 2018 to LAK 4,335,226 and LAK 1,872,633, respectively. Using the affordability criteria, the average monthly bill (average charge) of LAK 21,649which equivalent to $2.70. This is equivalent to only 1.16% of the estimated monthly income of poor families when the Kaysone Wastewater Treatment subproject starts full operation in 2018.6. In all subsequent years, the minimum monthly bill a little over 1% of the estimated monthly incomeof the family in the low income group. Hence, the proposed level of wastewater fee which should not exceed 5% is deemed affordable to the low income or poor families. Table 25 shows the detailed annual estimates of the affordability analysis.

Table 25: Analysis of Wastewater Fee Affordability


8.3 Economic Feasibility

8.3.1 Methodology

An economic evaluation of the proposed subproject is done to determine its economic viability. The economic evaluation follows the methodology of determining the economic viability of an investment by computing the following indicators: economic internal rate of return (EIRR), benefit-cost ratio (BCR) and the net present value (NPV).

The basic approach is to determine the economic benefits accruing from the investment and associated economic costs over the entire life of the subproject, finding the discount rate that would equalize the benefits and costs or discounting the net economic benefits by an assumed economic opportunity cost of capital (EOCC). An EIRR greater than the EOCC, or a BCR of greater than 1.0, or a positive NPV, indicate that the investment is economically viable.

Affordability Analysis 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Household Income (LAK/ household/month)

Average Income Household 2,980,194 3,144,104 3,317,030 3,499,467 3,691,937 3,894,994 4,109,219 4,335,226 4,573,663 4,825,215

Low Income Household 1,287,317 1,358,119 1,432,816 1,511,621 1,594,760 1,682,471 1,775,007 1,872,633 1,975,628 2,084,287

Average waste bill per HH 21,649 21,649 21,649

% of monthly income

Average Income Household 0.50% 0.47% 0.45%

Low Income Household 1.16% 1.10% 1.04%



The EIRR is computed using a discount rate of 12%, which is the assumed economic opportunity cost of capital (EOCC). Economic benefits and costs are estimated over the economic life of the new investments which is expected to be about 30 years. The analysis follows the procedures and guidelines in the ADB Guidelines for the Economic Analysis of Projects (1997) and the Framework for the Economic and Financial Appraisal of Urban Development Projects (1994).

8.3.2 Economic Costs

Economic costs were derived from the financial estimates of the capital investments and the operating and maintenance costs of the subproject, net of all duties and taxes, and converted using appropriate price conversion factors. Traded and non-traded components of both investment and O&M costs were estimated. The price conversion factors used, as estimated by ADB and used in all infrastructure investment projects, are as follows: (i) a shadow exchange rate factor of 1.1 for tradable costs, (ii) a shadow wage rate factor for unskilled labor of 0.75 and a shadow price factor for skilled labor of 1.0.

Other assumptions used in computing for the economic costs are as follows:



Table 26: Economic Cost Assumptions

Foreign Exchange Rate $1.00 = LAK 4,127

Physical Contingency 10% of direct cost

Detailed Engineering Design 5% of direct cost

Construction Supervision 3% of direct cost

Foreign Cost Component – Civil Works 60%

Foreign Cost Component – Equipment 90%

Implementation Schedule Detailed engineering design – year 1 Resettlement - year 1 Civil works - year 2-5


Using the above assumptions, the total economic cost of the proposed subproject is about $6.673 million from the financial cost of $7.016 million. Details of the economic cost computation are shown in the following table:

Table 27: Summary of Economic Costs ($ million)


8.3.3 Economic Benefits

The basic assumption is that the subproject will lead to a better wastewater management system, including improved wastewater collection infrastructure, establishment of wastewater treatment and disposal facility. The system is expected to:

a) Reduce the sanitary and health risks at collection, treatment and disposal of wastewater;

b) Improve environmental conditions; and

c) Reduce unsanitary disposal of untreated wastewater.

The above will in turn lead to other benefits that add to the project‟s socio-economic desirability, such as the following:

Financial Costs Financial Costs Excluding Tax Total

Exclude Unskilled Labor Skilled Labour Local Material Foreign Costs a/

Economic

Total Taxes & Duties Percent Total Percent Total Percent Total Percent Total Costs

Land Acquisition/Resettlement 1.140 1.140 0% - 0% - 0% - 0% - 1.140

Civil Works

Southern 1.778 1.600 12% 0.192 18% 0.288 10% 0.160 60% 0.960 1.648

Central 0.571 0.514 12% 0.062 18% 0.093 10% 0.051 60% 0.308 0.529

Northern 1.221 1.099 12% 0.132 18% 0.198 10% 0.110 60% 0.659 1.132

Equipment

Pumps 1.410 1.269 0% - 5% 0.063 5% 0.063 90% 1.142 1.383

Diesel Generator - - 0% - 5% - 5% - 90% - -

Total Base Costs 6.120 5.508 0.386 0.642 0.385 3.070 5.833

Physical Contingency 0.498 0.448 0% - 0% - 62% 0.278 38% 0.170 0.465

Design 0.249 0.224 0% - 55% 0.123 0% - 45% 0.101 0.234

Supervision 0.149 0.134 0% - 55% 0.074 0% - 45% 0.061 0.141

Total Initial Capital (Project) 7.016 6.315 0.386 0.839 0.663 3.402 6.673



a) Decreased cost of health care;

b) Decreased illness and deaths brought about by better sanitation;

c) Benefits of decreased pollution/damage of land and water bodies;

d) Increase in land value;

e) Improved waste management, which results in improved environment; and

f) Job creation during construction and operation of the new landfill and other facilities.

In order to value the above-mentioned benefits, the direct beneficiaries‟ willingness to pay may be used as proxy indicator of the total perceived benefits that the beneficiaries will derive from the project. The willingness to pay information was to be derived from the result of the socio-economic survey undertaken under this project. However, because there was a problem with the generated information, the assumption was based on informants‟ interviews where it was assumed that the people‟s willingness to pay is equivalent to the current fee of LAK 2,000 per household per month.

Other quantified benefits used in the evaluation are the increase in land value in areas directly benefitted by the subproject and health cost savings that the people will derive from improved environmental sanitation. The quantified benefits are based on the following assumptions:

Table 28:Economic Benefit Assumptions

Land Appreciation Unit Value

Minimum residential land price LAKmn/sqm 0.321

Incremental % % 5%

Expected land price after infrastructure improvement LAKmn/sqm 0.337

Land Appreciation LAK/m2 16,036

Land Appreciation $/m2 2.00

Area of land appreciated m2 6,714,000

Total land appreciation $ million 13.428

Health Savings Unit Value

Average person per household Person 5

Per household monthly income (survey) LAK/month 2,980,194

Health expenditure as % of income 1%

Health saving percentage due to project 20%

Health bill per capita LAK/yr 14,901

Health saving per person per year LAK 7,152

Health saving per person per year USD 0.9


8.3.4 Results of Evaluation

Based on the quantifiable benefits and assumptions discussed above, the economic feasibility of the subproject was determined by computing the economic internal rate of return (EIRR) and net present value (NPV). Sensitivity tests were carried out to determine the impact of changes in key input variables on the viability of the investments. As shown in



Table 9, the economic viability of the proposed subproject is positive which means that the economic benefits are sufficient to justify the economic costs of the project. The base case and the sensitivity analyses undertaken have EIRRs above the EOCC, BCRs are above 1.0 and NPVs at 12% are positive.

Table 29: Summary Result of Economic Evaluation

Base Sensitivity Analysis

Case Cost

(+10%) Ben (-10%) Cost (+10%) Revenues


One Year

Economic Internal Rate of Return 27.07% 22.65% 22.17% 17.56% 18.91%

Benefit Cost Ratio 1.78 1.62 1.60 1.46 1.78

Net Present Value 1.95 1.41 1.21 0.67 1.15 Source: GMS Corridor Towns Development Project. (TA 7644-REG)

8.3.5 Distribution of Net Economic Benefits

The subproject has clear and specific target beneficiaries. It includes the urban residential and commercial areas. With a total area of 11.19 square kilometers planned as coverage of the proposed wastewater system, it would cover a total of 16,000 households by year 2018. At an average household size of 5 members, the magnitude of beneficiaries of this component ia about 80,000 people. In Kaysone Phomvihane, the poverty threshold in 2011 was LAK 779,420/household/month. For the low income group, average monthly income per household is LAK 1,247,318. The results of the socio-economic survey confirmed that about 23% of households are considered below the poverty threshold while 50.3% are considered in the low income group.

Analysis of gainers and losers shows the households to be the biggest gainers (69.7%) while commercial/business establishments are expected to gain about 28.9% of the total net benefits. The labor sector, through participation in the construction works and operation will gain 5.8% of the net economic benefits. On the other hand, the government will lose by 4.5% as a result of the differential cost of foreign exchange as indicated by SERF. The poverty impact ratio (PIR) for the investments is estimated at 26%.

Table 30: Computation of Poverty Impact Ratio

City Business

Residents Sector Labor Government Total

Gains and losses 8.52 3.50 0.87 (0.68) 12.21

Distribution (%) 69.8% 28.7% 7.1% -5.5% Proportion of poor 0.23 0.23 0.50 - Benefits to poor 1.96 0.81 0.43 - 3.20

Poverty impact ratio (PIR)

26%


Details of the economic evaluation are shown in the following table:

Table 31:Result of Economic Evaluation




8.4 Environmental Aspects

8.4.1 Preliminary Identification of environmental impacts and mitigation

measures

The Wastewater Treatment Subproject is done in the urban area of Kaysone Phomvihane. All the alignments for drainage and pipes already have canals, which will be improved. The site for the Wastewater Treatment Plant (WWTP) is a newly acquired land. This land is cleared and has previously been developed. This means that no vulnerable ecosystems are disrupted by this project, as the entire implementation will be in an urban setting.

During the project construction, impact will concern land holders and the immediate surroundings in terms of dust, exhaust and noise. The impacts on individual ownership are significant, and the LAR issue on the site of the treatment plant must be mitigated. Apart from this, the adverse impacts will be very low if the construction takes place in dry season. During the project operation, noise from water pumps and odour from wastewater treatment ponds would impose impacts on surrounding areas but these are unlikely to be very significant.

During operation, the discharge from the new wastewater treatment plant must be monitored closely in order to ensure that the quality of the discharge meets the relevant laws and standards.

The social impacts which should be given special attention on mitigation are:

Year Project Incremental Project Net Sensitivity Analysis

Cost O&M Cost Benefits Flows Cost (+10%) Ben (-10%) Cost (+10%) Revenues


One Year

2013 0.23 - - (0.23) -0.26 -0.23 -0.26 -0.23

2014 1.61 - - (1.61) -1.77 -1.61 -1.77 -1.61

2015 1.93 (1.93) -2.12 -1.93 -2.12 -1.93

2016 1.93 - (1.93) -2.12 -1.93 -2.12 -1.93

2017 0.97 (0.97) -1.06 -0.97 -1.06 -0.97

2018 - 0.12 13.55 13.42 13.41 12.07 12.06 -0.12

2019 - 0.12 0.12 (0.00) -0.01 -0.01 -0.03 13.42

2020 - 0.12 0.12 0.00 -0.01 -0.01 -0.02 0.00

2021 - 0.12 0.13 0.00 -0.01 -0.01 -0.02 0.00

2022 - 0.12 0.13 0.01 -0.01 -0.01 -0.02 0.00

2023 - 0.12 0.13 0.01 0.00 -0.01 -0.02 0.01

2024 - 0.12 0.13 0.01 0.00 0.00 -0.02 0.01

2025 - 0.12 0.14 0.01 0.00 0.00 -0.01 0.01

2026 - 0.12 0.14 0.02 0.00 0.00 -0.01 0.01

2027 1.38 0.12 0.14 (1.36) -1.52 -1.38 -1.53 -1.37

2028 - 0.12 0.15 0.02 0.01 0.01 -0.01 0.02

2029 - 0.12 0.15 0.02 0.01 0.01 0.00 0.02

2030 - 0.12 0.15 0.03 0.02 0.01 0.00 0.02

2031 - 0.12 0.15 0.03 0.02 0.02 0.00 0.03

2032 - 0.12 0.16 0.03 0.02 0.02 0.01 0.03

2033 - 0.12 0.16 0.04 0.02 0.02 0.01 0.03

2034 - 0.12 0.16 0.04 0.03 0.02 0.01 0.04

2035 - 0.12 0.17 0.04 0.03 0.03 0.01 0.04

2036 - 0.12 0.17 0.05 0.03 0.03 0.02 0.04

2037 1.38 0.12 0.17 (1.33) -1.48 -1.35 -1.50 -1.34

2038 - 0.12 0.18 0.05 0.04 0.04 0.02 0.05

2039 - 0.12 0.18 0.06 0.04 0.04 0.03 0.05

2040 - 0.12 0.18 0.06 0.05 0.04 0.03 0.06

2041 - 0.12 0.19 0.06 0.05 0.05 0.03 0.06

2042 (1.99) 0.12 0.19 2.06 2.24 2.04 2.22 2.05

Total 7.45

EIRR 27.07% 22.65% 22.17% 17.56% 18.91%

BCR 1.78 1.62 1.60 1.46 1.78

NPV (@ 15%) 1.95 1.41 1.21 0.67 1.15



- Acquisition of land which must be subjected to a Resettlement Plan according to the guidelines of ADB.

During construction the EA and the contractor should continuously mitigate potential additional impacts. The construction can change the usual access roads for some people temporarily, and nuisances from noise and dust will occur. Information about this should be provided with enough time for the population to prepare for the situation.

Overall, the potential adverse environmental impacts that are associated with construction and operation of the proposed sub-project will be (i) temporary, (ii) mostly of low, with very few of medium significance and (iii) localized. These can be mitigated to acceptable levels through good engineering design and compliance with the recommended monitoring and management measures and procedures of the proposed EMP.

The Initial Environmental Examination has considered the preliminary project design, the baseline environmental conditions, possible impacts and mitigation measures and institutional arrangements to implement the same. Based on the findings of the IEE, the subproject is assigned a Category “B” under ADB classification. No detailed EIA needs to be undertaken to comply with the environmental policies of the ADB and the Government of Lao PDR.

The project is categorized as Environment category “B”, confirmed by the IEE. The proposed sub-projects are not expected to cause irreversible adverse environment impacts and these will be mitigated by adequate EMPs. An initial environmental examination (IEE) was prepared for each Project town. The IEEs, including the environment management plans (EMP) are based on Lao PDR‟s laws and regulations and ADB‟s Safeguards Policy Statement of 2009. The IEEs indicate that no specific environmental mitigations are necessary beyond adoption of best practice in the construction phase

.

8.4.2 Preliminary Environmental management and monitoring priorities

Environmental mitigation and management issues concerning the sub-project arise mostly in the construction phase. Mitigation should thus be centred around the need to ensure that the contractor acts in an environmentally responsible way. Therefore, an EMP should form part of the contract for construction. The EMP will specify the approach to construction site preparation and operation including pollution control and waste management. Penalties for non-compliance with the EMP must be drawn up by the PMU/PIT. Transgression from the specifications in the EMP may incur a fine or other penalty (to be specified in the Works Contract) unless rectified immediately.

The IEE contains the framework for an EMP which should be further developed during the Detailed Design phase. In the context of the project, the EA and civil works Contractor should commit to respect the following principles during the whole period of the construction activities:

• To manage construction activities with diligence and with the awareness that an important objective is to protect the environment and to minimize construction impacts, by employing the best control mechanisms, procedures and processes within the limits of their economic feasibility.

• To comply with GoL, and donor requirements and to provide self-monitoring to ensure compliance.

• To respect internationally recognized good practices in the fields of concern. • To provide effective environmental briefing to construction staff. • To ensure adherence to the EMP throughout the construction stage. • To efficiently implement measures outlined in this EMP and submit to regular

monitoring and auditing.



All contractual and legal obligations relating to the EMP should apply to both the civil Contractor and their Sub-Contractors. It should be the responsibility of the Contractor to provide adequate resources to ensure effective implementation and control of the EMP. Each Sub-Contractor should be responsible to its respective Contractor for compliance with the measures presented in the EMP. The Contractor and their Sub-Contractors should ensure that all project staff are briefed and procedures are understood and followed.

The EA will designate an Environmental Officer (EO) in the PMU and PIT while the contractor will nominate an environmental site officer (ESO).

The EO will be responsible for monitoring, reviewing and verifying compliance with the EMP by the Contractor. In addition, the EO will ensure that mitigation and compensation measures developed in the EMP at detailed engineeringdesign stage are implemented where applicable.

The ESO will be the contractor‟s focal point for all environmental matters and will be routinely on-site for the duration of the construction works. ESO will be appropriately briefed by the PMU. The ESO carries out regular inspections of the contractor‟s activities in relation to environmental issues, and provides day-to-day advice to Contractor about environmental issues.

In the operational phase, the discharge from the WWTP will be the major item to monitor and manage. If this is done in combination with best practice operational rules for the plant then impacts during the operational phase will be minimal.

8.5 Social Aspects

8.5.1 Description of direct and indirect beneficiaries

The Kaysone Phomvihane Wastewater Treatment subproject will directly benefit 80 % of the 2010 population which is equivalent to 61,524 inhabitants. At the 2 % annual population growth rate, the projected number of direct beneficiaries will be 91,200 by 2030. These beneficiaries include the women and children and poor households

Under this subproject, the primary stakeholders are the households and commercial enterprises (including market stall holders) who currently live along the open channels that convey combined wastewater and run-off and will benefit from improvement in health (reduced WBIs and missed work and school days) and their immediate urban environment.

This subproject will also contribute to addressing flooding issues along with the road improvement subproject. Secondary beneficiaries are the wider town population who will benefit in similar ways, for example health benefits and an improved urban environment (reduced potential for flies and disease vectors).

8.5.2 Result of socio-economic baseline survey and public consultations

As integral activity of Poverty and Social Assessment (PSA), ahousehold survey was designed to collect information from potential beneficiaries of the urban infrastructure under the Project. The survey was conducted in selected villages to represent the wider areas where the village leader was asked to identify poor areas and households so they could also be included in the survey. The survey form comprised six sections covering general information about the head of household; household demographics and housing; income and expenditure; access to and use of urban infrastructure, services and facilities, willingness to pay for new and improved services; and participation in community decision making and development.



To gather more detailed information, including thoughts and perceptions about the Project, consultations and focus group discussions (FGDs) with beneficiary villages were conducted alongside the survey of 200 randomly selected households in four villages. There were 1,205 people who participated in the survey that include 595 males and 610 females.

The survey results indicated that a third of households is headed by a woman; the largest proportion being captured in Sok village (half of the sample) and the smallest proportion (18%) being in Nakae village. The survey revealed that more than three quarters of heads of household (77%) are aged between 31 and 60 years old; with 56% being aged between 46 and 60 years old. A very small proportion (3%) of households heads are relatively young household heads (20 to 30 years old), 16% are aged between 61 and 75, and a small proportion (5%) are older than 75 years. The survey captured a large proportion of households with older household heads, with 14% aged 76 years or older.

Income and livelihood

The current livelihood engagement of the beneficiary households involve (a) agriculture including (i) rice and vegetable cultivation; (ii) cash crop production; and, (iii) livestock and poultry raising; (b) engaging in seasonal or casual livelihood activities such as daily labor to farming households during the planting or harvesting season, street vending, or waste picking; (c) employment for regular wages or salary; and, (d) other cash generating activities such as market trading or operating small household business or enterprise.

Many households have multiple income streams, regular or waged income is earned by 62% of households (smallest proportion of households located in Nalao (54%) and 70% of households the largest proportion in Thahae) and more than a third (36%) of households earn income from casual or daily labor. Sale of agricultural goods (crops or livestock) produced by the household contributes to income of households in Nakae (2%) and Ban Sok (16%) while 16% of households overall derive income from sale of other goods (food, rice alcohol and handicrafts), ranging from 6% in Ban Sok to 24% of households in Nalao. Income from non-wage sources such as remittances, pensions or rent represents a small proportion of household income and is earned by 3% of households.

Sanitation and Disposal

Most households (98%) in the survey sample usea flush/pour latrine, 1% use a bucket emptied elsewhere, and another 1% use either a public toilet or “open” toilet (stream, forest or field) and 10% described the toilet as “other”. All households in the 3rd and 4th income groups use flush/pour latrines compared with 92% of poor households. It is only poor households that use a bucket (5%) or an “open” toilet (2%).

All households in the highest income group and 98% of households in the 3rd income group compared with 85% of poor households own the toilet their household uses. For the poor households not owning the toilet they use, they either make use of a public toilet or use the toilet belonging to a friend or neighbour.

A large proportion of households (89%) stated the latrine they used was connected to a septic tank; 91% of households in the highest income group compared with 83% of poor households. For those households with septic tanks 10% are connected to a soakage pit and 3% discharge to the yard or garden or field, the largest proportion of households discharge to a public drain (41%) or canal (39%).

The main reason given by 73% of households for not connecting to a septic tank was that they did not know what one was, 2% of poor households (compared with none of the households in the other income groups) stated the cost of connecting was too high and they could not afford it.

To try and get a handle on coverage by sewerage, households were asked where the wastewater (excluding toilet water) generated by their household discharged to. Some 9% of households stated it discharged directly to the yard, garden or onto the road, two-thirds of households stated it discharged to a public drain or canal, 4% stated it discharged to a field, and for the remainder of households discharges of wastewater were poured into the toilet, or



to stream or river. A larger proportion or poor households (21%) compared with 2% of households in the highest income group discharge wastewater to the yard or garden and conversely a larger proportion of households in the high income group (a third) discharge to a canal compared with no poor households.

Nine households recorded members becoming ill with WBIs from open sewers with four males and five females becoming ill; four of these households were in the lowest income group (the poor). Sick days included 11 missed work days for the adults and seven missed school days for the children. The average cost of treatment was 214,000 kip, poor households paid 242,500 kip as the average cost of treatment and households in the highest income group paid 100,000 kip as the average cost of treatment.

12.4.3 Gender assessment

During the FGDs, women‟s group discussed problems facing poor families. Women in poor households had limited abilities in terms of education, skills and access to regular or reasonably well-paid employment. Oftentimes, they cannot provide basic needs for their households (food and clothing). Also noted was the homelessness of many poor families and those who live in very small houses and huts without proper facilities such as running water, latrines, and electricity. The houses and huts are located by the sides of streams or drainage channels where women and children suffer from illness during rainy season due to flooding. It was commented that many poor households are headed by widows who have to manage and earn money for the household family.

Gender Issues

The women considered the main challenges and issues facing the town in terms of development included; low household incomes; insufficient employment opportunities (especially for poor households) even students who graduate with qualifications cannot get jobs. Most people lack the skills or experience for the jobs that are available. There is also the increasing social problem associated with crime (burglaries) and drug use. The other concerns of women include: lack of funds for trading; lack of regulated micro-finance facilities offering low interest loans and increasing household debt due to informal credit traders (high interest charged by “loan sharks”);lack of regulated micro-finance facilities offering low interest loans and increasing household debt due to informal credit traders (high interest charged by “loan sharks”);insufficient market supply of vegetables; inadequate infrastructure especially roads, poor rubbish collection creating nuisance (flies and rats) and creating poor village environments; the lack of sufficient drainage and poor maintenance leading to blocked drains and pipes and flooding. Women complained about access difficulties to health facilities which do not have adequate services and equipment.

Mitigation Measures

The consultation process and focus group discussions with the women‟s group in Kaysone Phomvihane generated adequate information on the mitigation measures to address the gender related concerns and issues. Such measures form part of the gender strategies that are incorporated in the Gender Action Plan (GAP). The GAP measures are intended to achieve the following:

i. Increasing awareness of gender issues for beneficiary communitiesin respect of

urban development and to integrate gender targets and gender-disaggregated monitoring and evaluation tools in development plans, programs and projects

implemented by the EA in the urban development sector;

ii. Increasing women‟s participation in key decision-making and implementing structures of the Project, resettlement committees, village development committees,



iii. Active participation in the planning, design and implementation of urban infrastructure to ensure that provision of services are responsive to women‟s needs;

iv. Provision of opportunities for women to participate in training and awareness raising programs and increase up-take of training aimed at improving women‟s skills and marketability in the urban job market and to target women and the poor for construction-related employment;

v. Ensuring that information, education and communication (IEC) programs implemented under the Project properly target women and girls; and

vi. Increasing the participation by, and awareness of, women in communicable disease control and prevention in subproject areas.

Under the Project, the GAP will involve four essential components; 1) empowerment for women in urban community development through gender awareness and sensitization training programs for Project staff and community based training in subproject villages, 2) construction phase employment targeting 50% participation rate of women and poor in construction and civil works activities, 3) HIV and trafficking awareness and prevention involving contractor awareness training, community-based awareness, control and prevention activities and campaigns programs on gender sensitivities, and 4) road safety campaign involving girls as well as boys in school awareness campaign programs.

Subproject Impact on Gender

When discussing the Kaysone Phomvihane Wastewater Treatment, the women noted that this subproject would generally improve health conditions, particularly for those people living along the sides of streams and open canals which convey wastewater, effluent and storm-water run-off. The women‟s groupobserved that the sewers get blocked with rubbish because the solid waste collection service is not frequent enough. In the rainy season wastewater backs up and floods the low-lying areas adjacent to the Mekong River. As a result, the houses below the road get flooded and children suffer illness from water-borne illness (WBI) because the flood waters which contain sewage and effluents take a long time to recede. Stagnating pools of water are breeding grounds for mosquitoes.

The women‟s groups anticipate general environmental improvements with this subprojectsince with a clean environment, exposure to various illnesses including dengue fever will considerably reduce. Some women foresee environment concerns in terms of dust and noise pollution during construction and the removal of their vending stalls located across the drains during installation of new pipes. They however acknowledged that once the drainage canals and sewage pipes are installed, women could go back and rebuild their stalls The women wondered if it would be possible to ensure that construction vehicles only used certain routes. Based on their observations in previous construction works in their area, the roads were damaged by construction trucks since there were no alternate road that was constructed for the trucks and heavy vehicles.

The Kaysone Phomvihane Wastewater Treatment subproject will provide benefits to women at both an individual and household level. Improved wastewater treatment through upgrading of drainage network and sewage pipelines will mitigate contamination of the local environment and exposure to water-based illnesses (WBIs) from over-flow of drains which often carry run-off and wastewater. Women can benefit through avoiding the clean-up post-flood activities which normally take a lot of time of women from other doing other productive endeavors. This also reduces women‟s exposure to WBIs and the time they need to spend to care for sick household members.

The Project is classified as effective gender mainstreaming (EGM) which means that while Project outcomes may not be direct equality or empowerment for women, the Project will still be likely to provide benefits to women. The gender strategy in the GAP includes many opportunities to be built into the project design to ensure delivery of tangible benefits to women by improving access to urban environment infrastructure such as



8.5.4 Safeguards Assessment

The main social impacts during operation are as follows:

There will be no particular social concern but the growth of population and business investment can lead to health risk from sexual issue including HIV/AIDS and drug use which is already an issued in many villages. However, this can be prevented through local ordinances and regulatory measures to be issued by the District Authority of Kaysone Phomvihane.

Anticipated positive impacts are new livelihood opportunities from trading and other services.

The main social impacts during construction are as follows:

There will be no particular social concern during construction, although some minor impacts would relate to dust, noise and vibration are possible. Impacts on individuals‟ properties are reported but not significant. Unless satisfactory compensation are provided to affected households whose properties such as land, there will be expected arguments during the project construction.

Anticipated positive impacts are job opportunities for skilled and unskilled labourers as well as increase of trade and commercial opportunities brought about by influx of construction workers.

Land Acquisition and Resettlement

The land to be acquired for the subproject includes two sites of 2.7 ha for the northern and southern WWTPs and an area of 500 m2 for the septic tanks and pond for the central system. The central system will require 100 m2 of residential land to be acquired from each of five households adjacent to the stream. The sites proposed for northern and southern sites are within two large land-holdings that are used by members of the owners‟ families and others for gardening and growing vegetables (mostly lettuce and herbs and in the dry season and rice in the wet season).

LAR Impact

There will be permanent impacts on 70 m2 of small wooden stalls constructed over the drain opposite the Savanxai Market, these are being operated by five households. The impacts on 16 other stalls and kiosks constructed over the drains are temporary in that they will be removed during the works and replaced following completion of the works. These stalls are makeshift and include a table with an umbrella or shade blanket attached to poles and are often taken down each evening, they are easy to uplift and replace and are therefore not considered to be permanent effects.

In an area adjacent to Kilimang stream a small group of houses have constructed small buildings behind their houses on the bank of the stream. The ancillary houses structures (three outdoor kitchens and one latrine) belonging to four households will be removed by the works required along one of the existing channels for the northern system. Some 42 trees will also be removed including banana, coconut and bamboo.

There will be livelihood impacts created by the subproject works with the removal of the stalls and kiosks. Of the stalls affected none are registered businesses and are operated by the owners themselves i.e. they do not employ additional people. The shops/businesses operate 6-7 days per week and will be compensated for income based on the average earnings/income for 1.5 months. The 21 stall owners are also entitled to livelihood restoration and transition support equivalent to the value of the poverty line (240,000 kip per AP per household) for the construction period (1.5 months). The 12 AHs growing vegetables on land they use but do not own for the two WWTP sites will be compensated at the value of



loss of one season of crop based on the average reported annual income (two seasons of crop). In addition, at the southern WWTP site an area of 0.32 ha used for rice cultivation will be lost and is compensated based on the market value for rice pro-rated at yield (kg) per ha.

The subproject, although affecting a relatively small number of AHs traverses three villages as shown in the Table below.

Table 32: Affected Households by System Location and Village

Village Location of

system

Sex of HH Head Total no. of AHs Female Male

Houameuang Northern 0 10 10

Phonxai Central 1 19 20

Saphantai Southern 0 9 9

Total 1 38 39

Source: GMS Corridor Towns Development Project. (TA 7644-REG) Inventory of Losses Survey January 2012.

The subproject will affect 39 households.Three of the AH are headed by women. The total number of APs is 161 (78 males and 83 females).

Consultation and Participationduring Resettlement Plan Preparation

Consultative meetings and focus group discussions have been undertaken for the environmental and social impact assessments and on the resettlement plan (RP) as essential component activities for the preparation of the Kasyone Phomvihane Wastewater Treatment subproject feasibility study. The purpose of these events have been to; (i) introduce the Project and the subprojects to the beneficiaries in local communities participating in the Project (ii) identify impacts, receive feedback and identify measures to mitigate the impacts and risks; (iii) disclose the eligibility and entitlements for compensation under the Project; and (iv) record the response of beneficiary communities of the Project and its anticipated impacts.

The inventory of losses (IOL) survey has been conducted in a participatory manner, with the head of the household and spouse of the household head assisting in identification of affected assets and other IR impacts.

A total of 30 affected households (AHs) and stakeholders actively participated during the consultative meetings which included the presence of the village chiefs, the two land owners of the WWTP sites, the owners of the residential land required for the central system ponds, the users of the land (vegetable growers), owners of structures along Kilamang Stream, and stall-holders that will temporarily affected during construction works along the drains.

The main issues and concerns raised can be summarized as follows:

In general the Ahs support the subproject because the existing drainage system is old and damaged, drains are full of solid waste and very little clearing or maintenance work is done. In a number of sections the drains overflow onto surrounding land, in other areas the open drains create bad smells. The drainage system needs to be upgraded;

The AHs in the Kilamang Stream area voiced concerns about the stability of the bank during the works, their houses and other structures are constructed very close to the edge of the bank;

One of the owners of a WWTP site noted that improving the drainage would reduce the flooding of the land, each year the land is flooded and lower-land being submerged for up to three months. The land-holding is substantial in size



and by improving the drainage and constructing an access road to the WWTP site this would potentially enable the remaining land to be subdivided and sold as residential lots;

The existing drainage channel has a 2 m wide designated reserve and upgrading and lining the channel will not create any impacts on the adjacent land;

The issues raised by AHs in the vicinity of the Savanxai market noted that the area is very crowded and the road is narrow and people have constructed their small shops over the drains in a number of locations. They are aware the effects will be temporary and they can replace their stalls after the works have been completed. The entitlement for compensation is understood and is acceptable; and

Compensation must be paid to the affected persons at the current market rates, this has been discussed on an initial basis and will need to be confirmed in agreement with the AHs during the DMS and updating of the RP.

Cost of Land Acquisition and Resettlement

The costs for compensating lost assets (land, structures and trees) is US$1.021 million (8.17 billion Kip), livelihood restoration and support measures for vulnerable households come to US$15,936 (127 million kip) with a 10% contingency and 10% for administration charges the total estimate for the subproject is US$1.255 million (10.062 billion kip), as shown in Table 9.4.2. A detailed breakdown is provided in Table 9.4.6.

Summary of LAR Costs for Kaysone Phomvihane Wastewater Treatment Subproject

Summary Cost estimate

US$ Kip (000)

Land 1,018,000 8,144,000

Structures 2,440 19,520

Trees 1,140 9,120

Livelihood restoration + allowances 15,936 127,488

Contingency 103,948 831,581

Administration charges (implementation) costs 114,342 914,739

Total subproject estimate 1,255,806 10,062,128

Ethnic Group

Based on the household survey data in Kaysone Phomvihane, the Lao-tai ethnic groups account for 98% of the local population. The household survey confirms that in Kaysone Phomvihane, the majority of the beneficiaries are Lao with small numbers of Phoutai (1.5%) and other ethnic groups (recent Vietnamese and Chinese migrants) accounting for 0.5%. During the PSA survey, consultations with non-Lao ethnic groups were undertaken through meetings and focus group discussions (FGDs). The consultations undertaken indicated the following:

The people see themselves first and foremost as Lao, they hold Lao citizenship and communicate through Lao language in different facets of society such as marketing, business activities, political activities, and participation in village/district administration;



They have inter-married with other ethnic groups including Vietnamese;

The different ethnic groups live together in mixed communities, there is a high level of social/cultural homogeneity in the town;

There are no special agencies or government offices established in the towns to work with non-Lao people because the non-Lao do not exhibit differences which make them any more vulnerable or in need of special assistance than the Lao;

Amongst the different ethnic groups there is high support for the subprojects that seek to improve, upgrade and rehabilitate urban infrastructure as key and important facilities for community access to services and employment opportunities. Consultations have ascertained broad community support for the subproject; and

There is also both the willingness and capacity to participate in design, implementation, and monitoring of the investments. People commented on the benefits and positive impacts anticipated to result from subprojects, and have stated there are no constraints on the ability of people to participate in project benefits as a result of ethnicity or culture.

In recognition of the safeguards measures, the Projectwill not involve any activities or investments that will:

Provide for or allow commercial development of cultural resources or indigenous knowledge under the project;

Provide for or allow commercial development of natural resources that would impact the livelihoods or cultural, ceremonial or spiritual use of land that would impact the identity or community;

Provide for or allow restrictions in use of, or access to, protected areas and natural resources; or

Require displacement from traditional or customary lands.

There are no IP settlements or ancestral grounds located in the proximate distance to the Kaysone Phomvihane Wastewater Treatment Subproject. In effect, the subproject will not produce adverse impact such as disruption of traditions or rituals and displacements of IP resources and traditional livelihood activities. The Project will not adversely impact on, and is designed in such a way that it will respect the identity, dignity, human rights, livelihood systems and culture of the non-Lao ethnic groups in Kaysone Phomvihane. Any negative impacts on non-Lao will be the same as for Lao ethnic group, and these will be mitigated through implementation of the GAP, EMP and RP. The beneficiary communities are supportive of the subproject, and can see clear and direct benefits fromit. The assessment confirms the categorization of the Project is „C‟ which does not require preparation of an IP plan.

9 CONCLUSION

The Kaysone Phomvihane Wastewater Treatments subproject is recommended for investment support under the CTDP given the following consideration:



a. Technical elements – the installation of wastewater pipe line with the sewerage interceptors at the bottom of existing storm drainage canal and constructing the new wastewater piping to the Wastewater Treatment, and the installation of a new Wastewater Treatment and drainage pump station for flood control at southern Houay Longkong drainage system is a technically sound proposition. The improvement of urban drainage installation of the wastewater treatment around the Savanxay Market is easy to perform. Also, the construction of urban drainage system for a storm drainage system to northern Houay Khilamang drainage system with the sewerage interceptors for dry condition and installation of wastewater pipe line after the interceptors sewer to the new Wastewater Treatment is technically sound proposition.

b. Social dimension – the subproject will directly benefit 80 % of the 2010 population which is equivalent to 61,524 inhabitants. At the 2 % annual population growth rate, the projected number of direct beneficiaries will be 91,200 by 2030. These beneficiaries include the women and children and poor households. Under this subproject, the primary stakeholders are the households and commercial enterprises (including market stall holders) who currently live along the open channels that convey combined wastewater and run-off and will benefit from improvement in health (reduced WBIs and missed work and school days) and their immediate urban environment. The subproject will benefit the majority of the poor households who are vulnerable to the health related problems due to the poor environment conditions. It will improve the well-being and health of women and children with the reduction of water-borne illness and communicable diseases. It will also improve the participation of women in local decision making and will provide economic opportunities for women for gainful employment.

c. Environmental consideration – the subproject will mitigate contamination of the local environment and reduce health risks of the urban population. The subproject is assigned as Category B, which means that potential environmental impacts of project components are relatively minor. An initial environment examination (IEE) has been prepared for this subproject which indicates that no specific environmental mitigations are necessary beyond the adoption of best practice in the construction phase.

d. Institutional arrangements – a Project Management Unit (PMU) will be established to oversee the management and implementation of the subproject. At the corridor town level, the Project Implementing Unit (PIT) will be created to manage the day-to-day implementation of the subproject. The PIT will be managed by the Municipality Office of the Public Works and Transport. Both the PMU and PIT will closely coordinate with the Municipality Government of Kaysone Phomvihane District for the operation and maintenance arrangement for the subproject. After completion of the Wastewater Treatments starts operation, the wastewater quality shall be monitored regularly. The first year is assumed to be a period of tuning the process and analyses of inlet/outlet water and effluent should be reported 2 times per month. Further on, one report per month should be performed. The Wastewater Management Unit (WWMU) within the UDAA will be responsible for monitoring and reporting.

e. Economic and financial analysis – the subproject direct cost of three subsites amounts to $4.94million. The results of the economic and financial analysis indicate that the Subproject has and FIRR of 3.69% and NPV of $2.33 million; EIRR of 28.29% and NPV of $2.98 million; and poverty impact ratio of 26%.

f. Climate change impact adaptation - the subproject supports climate resilience in Kaysone Phomvihane Wastewater Treatment through the improvement of storm



drainage canals and the installation of sewerage pipes, flood control pump station that would reduce adverse impact of perennial flooding and contamination of the local environment.



APPENDICES

Appendix 1: Results of Lab Analysis of Wastewater Discharging

Appendix 2:Longitude Sections and Design Analysis for the Southern Wastewater System

Appendix 3: Wastewater Treatment Ponds – Design, Criteria, Analysis and Calculations Appendix 4: Requirements – Materials Appendix 5: Requirements for Aggregates Appendix 6: Requirements for Civil/Construction Works Appendix 7: Drawings

108 Appendix 2


Table A1: Results of Lab Analysis of Wastewater Discharging

Note: The samples taken at the time end of wet season, sample No.1 from southern drainage system Houay Longkong; sample No.2-central drainage system Savanxay Market-Chomkeo stream and sample No.3- northern drainage system Houay Khilamang.

Appendix 1 109


Layouts, Longitude Sections and Design Analysis for the Southern Wastewater System

Plans and longitutional profiles of sections alignment wastewater pipe line southern drainage system

110 Appendix 2


Table A2: Preliminary Design Test Calculation of Wastewater Pipe Line

Location: Southern drainage system, Between the Phokadouath road and downward to WWTP

Type Circular Pipe

Diameter, mm 400

Length of the pipe, m 40 specing between menholes


Qave

Flow Q m3/d 7560 Q=0.8pi x wc ÷ (1,000)

Flow q m3/s 0.0875 q=0.8pi x wc ÷ (1,000)*86400

Diameter D m 0.40

Flow area A m2 0.1256 A=3.14*D 2̂/4




Length L m 40





K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90

deg.bend



Location: Southern drainage system,between the canal junnction to Phokadouath road

Type Circular Pipe

Diameter, mm 400



Qave

Flow Q m3/d 7173 Q=0.8pi x wc ÷ (1,000)

Flow q m3/s 0.0830 q=0.8pi x wc ÷ (1,000)*86400

Diameter D m 0.40

Flow area A m2 0.1256 A=3.14*D 2̂/4




Length L m 50





K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90

deg.bend



Appendix 2 111


Location: Southern drainage system, between the canal junction and upward

Type Circular Pipe

Diameter, mm 300



Qave

Flow Q m3/d 2952 Q=0.8pi x wc÷ (1,000)

Flow q m3/s 0.0342 q=0.8pi x wc ÷ (1,000)*86400

Diameter D m 0.30

Flow area A m2 0.07065 A=3.14*D^2/4




Length L m 50

Gradient i 1/1000 0.0004 Manning formula i=(n2*V

2)/r^(4/3)


Velocity head V^2/2g m 0.0119 hs =k*V

2/2g; k=0.5 at entrance 1.0 at exit.

K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90 deg.bend



Note: the diameter of pipe line is on the big size but the area also high populated

Location: Northern wastewater pipe line

Type Circular Pipe

Diameter, mm 400



Qave

Flow Q m3/d 5906 Q=0.8pi x wc÷ (1,000)

Flow q m3/s 0.0684 q=0.8pi x wc ÷ (1,000)*86400

Diameter D m 0.40

Flow area A m2 0.1256 A=3.14*D^2/4




Length L m 50

Gradient i 1/1000 0.0004 Manning formula i=(n2*V

2)/r^(4/3)


Velocity head V^2/2g m 0.0134 hs =k*V

2/2g; k=0.5 at entrance 1.0 at exit.

K=1.5; k=0.13*2 at 45 deg. 0.20*2 at 90 deg.bend



112 Appendix 3


Wastewater Treatment Ponds - Design Criteria, Analysis and Calculations

Total volume = V = [LW + (L – 2sd)(W – 2sd) + 4(L – sd)(W – sd)]d/6 = Southern Aerated lagoon V=>(84*28+(84-2*3*2.5)*(28-2*3*2.5)+4*(84-3*2.5)*(28-3*2.5))*2/6= 3,174.0 m3 =>1.270 sqm (one of 2 cells of total 6,200 m3 /2,481sqm) Southern secondary sedimentation lagoon V=>(100*34+(100-2*3*2.5)*(34-2*3*2.5)+4*(100-3*2.5)*(34-3*2.5))*2.5/6 =6,175.0 m3 =>2,470 sqm (one of 2 cells of total 12,401 m3 /4,961sqm) Northern Aerated lagoon V=>(75*25+(75-2*3*2.5)*(25-2*3*2.5)+4*(75-3*2.5)*(25-3*2.5))*2/6 =m3 => 2,400.0 m3 =>960 sqm (one of 2 cells of total 4,554.0m3 /1,822sqm) Northern secondary sedimentation lagoon V=>(97.5*32.5+(97.5-2*3*2.5)*(32.5-2*3*2.5)+4*(97.5-3*2.5)*(32.5-3*2.5))*2/6= 4,538.0 m3 =>1,815 sqm (one of 2 cells of total 9,109 m3 /3,644sqm) Where: V = volume of pond or cell, m3

L = length of pond or cell at water surface, mC W = width of pond or cell at water surface, m s = slope factor (e.g., with 3:1 slope, s = 3) d = depth of pond, 1.5-3.3m (2.0m)

Appendix 3 113


Summary of dimensioning calculation of Aerated ponds wastewater treatment southern system

Flow

Population of the service area at year 2020 43068 Equivalent @180l/person.d

Per capita consumption 180l/person.day

Total average flow 6202 m3/d

Infiltration 0 m3/d 0 %


Organic load

Per capita BOD load 45.88 g/person.day

Domestic load 1976 kg/day

Industrial load 0 kg/day

Total BOD load 1976 kg/day

Average monthly mean ambient temperature 25.6 BC

Lowest monthly mean ambient temperature 23.7 BC

Partial Mix Aerated Lagoons

Volumetric loading rate 0.25 g BOD/day/m3

(between 0.1 to 0.4kg BOD/day/m3

depending on lowest average

temperature. 0.1 when temp.<14 C

and 0.4 when temp.>27 C)

Volume of ponds 6202 m3

Hydraulic retention time with dry weather tR 1 days

Adopted depth of ponds 2.50 m

Area of ponds at mid depth 2,481 m2

Number of ponds 2

Area of each ponds at mid depth 1,240 m2

Length to width aspect ratio 3 to 1

Pond side slope 1 to 3

Pond width at mid depth 28 m 20.5

Pond length at mid depth 84 m 76.5

Pond width at top water level 35.5 m 41.5

Pond length at top water level 91.5 m 97.5

Adopt BOD removal from Table above 65 %

BOD load in effluent 1550.4 kg/day

114 Appendix 3


Summary of dimensioning calculation of sedimentation pondswastewater treatment southern system

Flow


Per capita consumption 180l/person.day




Organic load







Secondary Sedimentation Lagoon






Volume of ponds 12,404 m3




Number of ponds 2










Appendix 3 115


Summary of dimensioning calculation of Aerated wastewater treatment ponds northern system

Flow


Per capita flow 180l/person.day




Organic load







Partial Mix Aerated Lagoons










Number of ponds 2

Area of each ponds at mid depth 969 m2









116 Appendix 3


Summary of dimensioning calculation of secondary sedimentation wastewater treatment ponds northern system

Flow


Per capita flow 180l/person.day




Organic load







Secondary Sedimentaion Lagoon










Number of ponds 2




Pond width at mid depth 32.5 m 25

Pond length at mid depth 97.5 m 90

Pond width at top water level 40 m 46

Pond length at top water level 105 m 111



Appendix 5 117


Requirements - Materials

Requirement for fill materials

AASHTO Sieve Percentage Passing (by weight) mm Designation

50.000 25.000 9.500 2.000 0.425 0.075

2 in 1 in

3/8 in No.10 No.40 No 200

80-100 30-60 12-30 7-15 2-10 0-5

Source:Technical Specifications for road construction works to Sekong5, September 2007

The gravel wearing course materials shall have the following gradins when tested in conformity with AASHTO T 88:

Requirement for gravel wearing course materials

AASHTO Sieve Gravel Wearing Course Material Percentage Passing ( by weight )

mm Designation Class 1 Class 2

50.000 2 in 100 100 37.500 1 ½ in 90 - 100 90 - 100 25.000 1 in 65 - 95 75 - 95 9.500 3/8 in 45 - 75 50 - 85 4.750 No 4 30 - 65 35 - 75 2.000 No 10 20 - 50 25 - 60 0.425 No 40 10 - 30 15 - 40 0.075 No 200 5 - 20 5 - 30

Source: Technical Specifications for road construction works to Sekong5, September 2007

Physical Requirements

The gravel in the mixed material shall have a loss of maximum 45 percent when tested for abrasion according to AAHTO T 96.

Other Requirements

Gravel wearing course material shall have the following characteristics when compacted on the road:

Gravel wearing course material’s characteristics

Item Description Test Method Requirements

No Class 1, Class 2

1. Atterberg Limits 1.1 Liquid limit (LL) AASHTO T 89 max 40 % max 50 % 1.2 Plasticity index (PI) AASHTO T 90 max 15 % max 20 %

2. Strength Tests 2.1 California Bearing Ratio (CBR) AASHTO T 193 min 30% min 25%

95% MDD of AASHTO T 180, Method D, 4 days soaked


118 Appendix 4


Requirements for Aggregates

2. The sources of supply of all fine and coarse aggregates shall be subject to the approval of the Engineer and unless otherwise directed by the Engineer, fine and coarse aggregates for concrete shall comply with the relevant requirements of B.S 882 or ASTM C33 as modified by any particular requirements in these Specifications.

3. All fine and coarse aggregates shall be clean and free from clay, loam, silt and other deleterious matter. Coarse and fine aggregates shall be delivered and stored separately at the Site. Aggregates shall not be stored on muddy ground or where they are likely to become dirty or contaminated.

Fine Aggregates

i) Fine aggregates shall be hard coarse sand, crushed stone or gravel screenings and shall conform to the requirements of B.S 882. Only fine aggregates of grading zones 1 to 3 (B.S 882) shall be used. ii) For exposed work, the fine aggregates shall be free from any substance that will discolour the concrete surface.

Table A5.1: Specific Requirements for Fine Aggregates

AASHTO Sieve Percentage Passing

By weight mm Designation

9.500 4.750 1.180 0.300 0.150 0.075

3/8 in No 4 No 16 No 50 No 100 No 200

100 95-100 45-80 10-30 2-10 0-4


Coarse Aggregates

4. Coarse aggregates shall be gravel or broken stone of hard and durable material free from laminated structure and shall conform to the requirements of B.S 882. Coarse aggregates shall be graded as follows for use in mass concrete , and in foundations:

Table A5.2: Specific Requirements for Concrete Aggregates

Sieve Number or Size

Total Passing Per Cent by Weight

76.20 mm 100

38.10 mm 95-100

19.05 mm 10-70

9.52 mm 10-35

No. 4 0-5

5. Coarse aggregates for all cast-in-place concrete other than mass concrete and for foundations shall be graded with the following limits:

Appendix 5 119


Sieve Number or Size

Total Passing Per Cent by Weight

38.10 mm 100

19.05 mm 95-100

9.52 mm 25-55

No. 4 0-10

120 Appendix 6


Requirements for Civil/Construction Works

12.4.4 Concrete Works

All cement used in the Works shall be Ordinary Portland Cement (OPC) complying in every respect with BS 12 or ASTM C-150 or equivalent at the time of use. :

a) Ordinary or rapid hardening Portland cement complying with the requirements of B.S 12 or ASTM Designation: C 150 Type II, and

b) Sulphate resisting Portland cement complying with the requirements

of B.S 4027 or, ASTM Designation: C 150 Type V.

Unless otherwise specified, ordinary Portland cements complying with the

requirements of B.S 12 or ASTM Designation: C 150 Type II shall be used.

Related Standard

Latest editions of the following British and ASTM Standards are relevant to the Specifications.

Construction Joints

Construction joints shall be watertight. They shall be formed in straight lines with rigid formwork perpendicular to the principal line of stress and as far as practicable at points of least shear. They shall be the plain butt type unless otherwise specified or approved.

Nominal Concrete Mixes Designed Mixes, Proportions of Mixes of Concrete

Concrete mixes for the specified various classes of concrete, set out icomply with the requirements of Specifications. The cement, fine aggregates and the coarse aggregates shall be weighed separately. The proportions of cement to fine aggregates and coarse aggregates shall be adjusted as to provide the concrete of the required compressive strength when tested as set out in the table below:

Table A6: Strength Requirements for Portland Cement Concrete

Class of Concrete Class(1) Min. Cement per Cu.m of compacted Concrete (kg) (2)

Cylinder strength at 28 days after mixing and curing in the works (N/mm2) (3)

Maximum water consumption per 50 kg. Bag of Cement (litre) (4)

Reinforced Concrete 40 Reinforced Concrete 35 Reinforced Concrete 30

450-475 400-425 356-400

40 35 30

19.45 20.25 22.50

Reinforced Concrete 25 320-350 25 24.00 Reinforced Concrete 20 250-300 20 27.50 Lean Concrete 15 170-225 15 33.00

Source: Technical Specifications for road construction works to Sekong5, September 2007

Steel reinforcement for concrete and steel works

Steel Reinforcement for Concrete

Appendix 6 121


Materials steel reinforcement shall unless otherwise specified, be deformed high yield steel bars to ASTM Specifications Grade 60 or equivalent, having a minimum yield-point stress of 400 N/mm2.

Unless otherwise specified, all deformed round steel reinforcing bars and plain mild steel reinforcing bars shall comply with the requirements of ASTM Designation: A 615 "Deformed and Plain Billet-Steel Concrete Reinforcement" Grade 40 and shall have a minimum yield

stress of 276 N/mm2.

Related Standards

Latest editions of following British and ASTM, Standards are relevant to these Specifications wherever applicable:

British Standards B.S 693General requirements for oxy-acetylene welding for mild steel. B.S 785Hot rolled bars and hard drawn wire for reinforcement of concrete. B.S 1856General requirements for the metal are welding of mild steel. B.S 4449Hot rolled steel bars for reinforcement of concrete. B.S 4461Cold worked steel bars for reinforcement of concrete. B.S 4466Bending dimensions and scheduling of bars for reinforcement of concrete. ASTM Standards A 305 Minimum requirements for the deformations of deformed steel bars for

concrete reinforcement. A 615Deformed and plain billet-steel bars for concrete reinforcement.

For each consignment delivered to certificates from the reinforcement manufacturer covering all tests required by ASTM A615.

The bars used shall have minimum diameters (between the deformation ridges) as specified in the following.

Minimum Diameter of Steel Reinforcing Bars

Size specified on Drawings Minimum Diameter (mm) Weight in Kilograms per meters

D 6 5.8 0.222 D 8 7.8 0.395 D10 9.8 0.616 D12 11.7 0.888 D16 15.5 1.578 D20 19.5 2.466 D22 21.5 2.984 D25 24.5 3.853 Source: Technical Specifications for road construction works to Sekong5, September 2007

122 Appendix 7


DRAWINGS

Preliminary engineering design drawings Southern drainage system

1. General Plan and layout of Kaysone Phomvihane Wastewater Treatment Subproject 2. Plan and Layout Houay Longkong Drainage and Wastewater Treatment Systems 3. Plans and Longitude of the sections along the alignment of southern drainage system 4. Southern Drainage System Houay Longkong Plan of Treatment Plant 1:500 5. Southern Drainage System Houay Longkong Cross Section of Treatment Ponds 6. Typical Manhole for the under ground wastewater pipe line to treatment plant 7. Overflow Interceptor at street crossings - typical detail 8. Typical of Manhole for Maintenance of Wastewater Pipe Line 9. Cross Section of Existing Canal with Wastewater Pipe Line Typical 10. Cross Section of New Canal Section 11. Cross Section and Plan for Sliding Gate and Pumping Station

Central drainage system

1. Plan and Layout of Central Drainage System Around the Savanxay MarkeArea 2. Plan of Wastewater Treatment Plant with a Septic Tank Filter0 3. Cross Section Septic Tank Filter;1:500 4. Plans and longitude of the alignments urban drainage culvert around the Savanxay

market; 5. Typical Manhole for Urban Drainage Culvert Around the Savanxay Market

Northern drainage system

1. Plan and Layout of Northern Drainage System Houay Khilamang 2. Plans and Longitude of the Sections Along the Alignment Wastewater Pipe Line 3. Plan ofWastewater Treatment Pondsfor the Northern Drainage System Houay

Khilamang1:500 4. Cross Sectionsof Wastewater Treatment PondsNorthern Drainage System 5. Typical Manhole for the Urban Drainage Culvert for the Area Adjacent to the

Northern Side of Savanxay Market:500 6. Typical Manhole for the Under Ground Wastewater Pipe Line to Treatment Plant 7. Overflow at Upper Connection - typical details

Appendix 7 123


Figure A7.2.1: General Plan and layout of Kaysone Phomvihane Wastewater Treatment Subproject

Source: No source provided.

124 Appendix 7


Figure A7.1.2 Plan and Layout Houay Longkong Drainage and Wastewater Treatment Systems


Appendix 7 125


Figure A7.1.3 Plans and Longitude of the Sections Along the Alignment of Southern Drainage System


126 Appendix 7


Figure A7.1.3 Plans and Longitude of the Sections Along the Alignment of Southern Drainage System


Appendix 7 127


Figure A7.1.4: Southern Drainage System Houay Longkong Plan of Treatment Plant 1: 500


128 Appendix 7


Figure A7.1.5 Southern Drainage System Houay Longkong Cross Section of Treatment Ponds


Appendix 7 129


Figure A7.1.6: Typical Manhole for the Underground Wastewater Pipeline to Treatment Plant


130 Appendix 7


Figure A7.1.7: Overflow Interceptor at Street Crossings - Typical Detail


Appendix 7 131


Figure A7.1.8: Typical of Manhole for Maintenance of Wastewater Pipe Line


132 Appendix 7


Figure A7.1.9: Cross Section of Existing Canal with Wastewater Pipe Line Typical


Appendix 7 133


Figure A7.1.10: Cross Section of New Canal Section


134 Appendix 7


Figure A7.1.11: Cross Section and Plan for Sliding Gate and Pumping Station


Appendix 7 135


Figure A7.2.1: Plan and Layout of Central Drainage System Around the Savanxay Market Area


136 Appendix 7


Figure A7.2.2: Plan of Wastewater Treatment Plant with a Septic Tank Filter0


Appendix 7 137


Figure A7.2.3: Cross Section Septic Tank Filter


138 Appendix 7


Figure A7.2.4: Plans and Longitude of the Alignments Urban Drainage Culvert Around the Savanxay Market


Appendix 7 139


Figure A7.2.5: Typical Manhole for Urban Drainage Culvert Around the Savanxay Market


140 Appendix 7


Figure A7.3.1: Plan and Layout of Northern Drainage System Houay Khilamang


Appendix 7 141


Figure A7.3.2: Plans and Longitude of the Sections Along the Alignment Wastewater Pipe Line


142 Appendix 7


Figure A7.3.3: Plan of Wastewater Treatment Ponds for the Northern Drainage System Houay Khilamang


Appendix 7 143


Figure A7.3.4: Cross Sections of Wastewater Treatment Ponds Northern Drainage System


144 Appendix 7


Figure A7.3.5: Typical Manhole for the Urban Drainage Culvert for the Area Adjacent to the Northern Side of Savanxay Market:


Appendix 7 145


Figure A7.3.6: Typical Manhole for the Under Ground Wastewater Pipe Line to Treatment Plant


146 Appendix 7


Figure A7.3.7: Overflow at Upper Connection - Typical Details
