Cambodia Municipal Wastewater
Treatment System
Mr. HENG Rathpiseth,By
Director of Road Infrastructure Department,
Ministry of Public Works and Transport

Mr. HEANG Vutha

Director of Sub-national Public Infrastructure and Engineering
Department, Ministry of Public Works and Transport

Japan, 28th July 2016

Contents
1.
2.
3.
4.
5.

6.
7.

Cambodia Profile
Strategy & Goal
MPWT Organization Chart
Relevant Environmental Laws & RegulationRole and Financial responsibilities of planning,development and management of municipal wastewater
treatment
Planning and On-going projects for the municipal
wastewater treatment systems.
Issues and challenges of the planning, Development,
and management of municipal wastewater treatment
systems.

2

1. CAMBODIA PROFILESouth-East of Asia- North
connected by the Loas,the East to theVietnam, the South-by the Golf Sea ofThai and the West- by the Thailand.
Land Area 181.035 Km2 .
Population : 14.8 million
The main religion is Buddhism.
Capitalcity : Phnom Penh
Population: 2,614,440
Total Number of Provinces andMunicipality: 24*
Total of district: 159*
Total Communes: 1406*
GDP Annual Growth Rate:
7.20% ( Average )* data sources 20123

2. Strategy and Goal
Rectangular Strategy-Good
Governance: Promotion of

Economic Growth; Generation of
Employment; Implementation ofGovernance AP; and Enhancing
Efficiency and Effectiveness in
implementing the reform programs.
The Government of
Cambodia (GOC) has
adopted the Millennium
Development Goal (MDG)
targets for water supply andsanitation, specifying that, by 2015,
80% of the urban population and
50% of the rural population shouldhave access to safe water, and that
74% of the urban population and
30% of the rural population shouldhave access to improved sanitation.
43. ORGANIZATION CHART OF THE MINISTRY PUBLIC WORKS
AND TRANSPORTMINISTERSECRETARYOF STATEUNDER SECRETARYOF STATE

ADVISORS

PUBLIC WORKS REGIONSGENERAL DIRECTORATE
OF ADMINISTRATIVESERVICES

GENERAL DIRECTORATE OF
TRANSPORTADMINISTRATIONDEPARTMENT
25-MUNICIPAL&PROVINCIAL PUBLIC
WORKS AND TRANSPORTDEPARTMENTS

GENERAL DIRECTORATE OF
PUBLIC WORKS

GENERAL INSPECTORATE

DEPT. OF ROADSSIHANOUK VILLE PORT

DEPT. OF LANDTRANSPORTDEPARTMENT OFPERSONELHUMANRESOURCESAUTHORITYHAVY EQUIPMENTCENTER

DEPT. OF WATER
TRANSPORTPHNOM PENH PORTAUTHORITY

DEPT. OFACCOUNTANT&FINANCE

PUBLIC WORKSRESEARCH CENTER
DEPT. OF MARCHAND
MARIINE

DEPT.OF PLANNING

CAMBODIA SHIPPINGAGENCY and BROKERCAMSAB

DEPT. OF SUBNATIONAL
PUBLICINFRASTRUCTURE AND
ENGINEERING

DEPT. OF INLAND WATERWAY

ROYAL RAILWAY OF
CAMBODIA

ROAD MAINTENANCE
CENTER

5

Department of Sub-National
Public Infrastructure and Engineering

Office ofAdministrative

Office ofFinance andaccounting

Office of Road
infrastructuretechnical and
Planning

Office ofEngineering

Office ofPlanning andTechniques for
Wastewater
treatment

Office of Roads inCapitals, Provinces,
Cities and Towns

Office ofWastewater andtreatment plantand solid waste
management

Office of Environment
and Public Service
SystemOffice ofSewerage system

Office ofLegal affair andbusiness6

4. Relevant Environmental Laws & Regulation
Relevant Environmental Laws and Regulation in Cambodia

Title

Objectives

Provisions

1993 Royal Decree
on Creation and
Designation ofProtected Areas

Protect the environment, manage natural resources,
conserve biological diversity and ensure sustainable
development in the national system of protectedareas.

Prescribes the responsibility for the national
protected areas system, which includes planning,development, and management; designation ofnational parks, wildlife sanctuaries, protected
landscape, and multiple use areas; amendment andapplication.

1996 Law on
Environmental
Protection andNatural Resource
Management

Protect, manage and enhance the environment, andto promote socioeconomic development in asustainable way.

National and regional environmental plans;
environmental impact assessment; natural resourcesmanagement; environmental protection; monitoring,record-keeping and inspection; public participation
and access to information; environmental
endowment fund; and penalties.

1997 Sub-Decree
No. 57 on the
Organization andFunctioning of the
Ministry ofEnvironment

Supervise and manage the environment throughout
the Kingdom of Cambodia. In particular:
protect and promote environmental quality andpublic health through the prevention, reduction andcontrol of pollution; assess the environmental
impact of all proposed projects prior to theissuance of a decision by the Royal Government;
ensure the rational and sustainable conservation,
development, management and use of the natural
resources of the Kingdom of Cambodia; encourage
and enable the public to participate inenvironmental protection and natural resourcesmanagement; suppress acts that cause harm to theenvironment.

A National Environmental Plan and Regional
Environmental Plans are required to be decided by
the Royal Government and reviewed and revised
once every five years.
Planning and management of protected areas,
supervision and coordination of protection andconservation of the environment are theresponsibility of the Dept. of Nature Conservation
and Protection.
Provincial department of environment is under the
direct control of the Ministry of Environment,
responsible for the supervision and management ofenvironment in its province/municipality.

1999 Sub-Decree
No. 27 on Water
Pollution Control

Determine water pollution in order to prevent andmitigate water pollution in public waters, and thus
ensures human health and conservation of
biodiversity.

Prescribe disposal of waste and hazardous
substance, permit of effluent, pollution control, andprocedures of inspection; the standards of7discharge/disposal of waste.

Relevant Environmental Laws and Regulation in
Cambodia1999 Sub-Decree
No. 72 on
Environmental
ImpactAssessment

Determine environmental impact assessment
on private and public projects andactivities, which are reviewed andassessed by the Ministry of Environment
before the Royal Government’s approval;
determine type and size of proposed,
existing projects and activities of bothprivate and public sectors which are
subjected to EIA; promote public
participation in EIA process and public
hearings in the process of projectapproval.

Prescribes institutions’ responsibility; EIA
requirements for proposed project,
procedures for the process of review andassessment of proposed projects, andexisting activities, and terms of projectapproval.
Note subsequent 2000 Prakas on Guidelines
for Conducting EIA Report.

1999 Sub-Decree on
Solid Waste
Management

Regulate solid waste management to ensure
the protection of human health and theconservation of biodiversity.

Applies to all activities relating to the disposal,
storage, collection, transport, recycling,
dumping of garbage and hazardous waste,
and includes household waste
management, hazardous waste
management and monitoring andinspection of hazardous waste
management.

2007,29 June Water
Resources
Management
Law inKingdom of
Cambodia

For managing and monitor the use of Water
Resources on Land, under ground and in
the Climate.

Applies to all activities relating with water
resources in Cambodia.

8

Water quality standard in public water areas forbio-diversity conservation in Cambodia
No.
Parameters
River
1
pH
2
BOD5
3
Suspended Solid
4
Dissolved Oxygen
5
Coliform
Lakes and Reservoirs
1
pH
2
COD
3
Suspended Solid
4
Dissolved Oxygen
5
Coliform
6
Total Nitrogen
7
Total Phosphorus
Coastal water
1
pH
2
COD
3
Dissolved Oxygen
4
Coliform
5
Oil content
6Total Nitrogen
7
Total Phosphorus

UnitStandard value

mg/l
mg/l
mg/l
MPN/100ml

6.5-8.5
1-10
25-100
2-7.5
<5000

mg/l
mg/l
mg/l
MPN/100ml
mg/l
mg/l

6.5-8.5
1-8
1-15
2-7.5
<1000
0.1-0.6
0.005-0.05

mg/l
mg/l
MPN/100ml
mg/l
mg/l
mg/l

7-8.3
2-8
2-7.5
<1000
0
0.2-1
0.02-0.09

Source: Annex 4, Sub-Decree on Water Pollution Control, 1999

9

5. ROLE AND FINANCIAL RESPONSIBILITIES OF PLANNING
DEVELOPMENT AND MANAGEMENT OF MUNICIPAL WASTEWATERTREATMENTKey
Ministries
Ministry of
Economic and Finance
Ministry ofEnvironment

Key
Schemes- Allocating budgets- Environmental planning ; monitoringof effluent discharged to waterways / water drains- Involve in Master plans

Ministry of
Pubic Works andTransport- Developing scientific national policy concerning all public works
construction- Master plan.

Ministry ofInterior andmunicipalities- Involve in Master plans.
- Operation and maintenance wastewater treatment system

Multilaterals
involved insanitationin Cambodia
106. PLANNING AND ON GOING PROJECTS FOR MUNICIPAL WASTEWATERTREATMENT

11

Concept Wastewater Management•Geographical Relief
1.The water network in Cambodia is divided into three systems: The Mekong River system, the Tonle Sap Lake system andthe Coastal Zone. The hydrological systems are central to life in Cambodia and Phnom Penh itself is located on theconfluence of three important rivers; the Mekong, the Tonle Sab and the Bassac.
2.The Tonle Sap System includes the Tonle Sap Lake, the Tonle Sap River and their Tributaries. The Tonle Sap Lake is thegreatest source of fish in Cambodia and as a result experiences the greatest population density as many people rely on thelake as a form of income.
•Treats to Wetlands in Cambodia
1.Point source of pollution to wetlands comes from industry and urban sewerage. Regardless of the relatively small amountof raw sewerage, its direct discharge into the environment without primary treatment raises concerns over pollution loads inassociated waters.
•The Tonle Sap Biosphere Reserve
1.Biosphere Reserves (BR) are areas of terrestrial coastal ecosystems promoting solutions to reconcile the conservation of
biodiversity which it’s sustainable use. They are intended to fulfill three basic functions including conservation,
development and logistic function. The Tonle Sap Lake was designated a Biosphere Reserve upon approval for its inclusionin the World Network of Biosphere Reserves by the International Coordinating Council for UNESCO’s Man and Biosphere(MAB) reserve programmed in 1997. The designation reflects the importance of the Tonle Sap Lake ecosystem for its
ecological function and for supporting socio-economic development and the maintenance of associated cultural values.
•The Coastal Zone
1.The coastal zone (CZ) of Cambodia extends for 435km and consists of estuaries, bays and 64 islands of various sizes.
Most of the coastal population is concentrated in Sihanoukville where urban services and employment opportunities areavailable and in Kampot, where good soil conditions and access to water enables rice culture. Cambodia does not yet acomplement of coastal and marine environmental policies. As development pressures are rapidly mounting there is anurgent need for safeguards to be put in place that will allow economic development while ensuring the sustained quality ofcoastal and marine environments and the resources they provide.
•Development Plan
1.Development strategy which contributes to the regional development and poverty reduction. The long term plan todevelop the Multiple Economic Development Zones.
2.The priority wastewater management plan: Short term plan: Sihanoukville and Siem Reap Town; Medium term plan:
Kampot, Kep, Poipet, Battambang, Bavet, Pursat, Serei Sophon and Stueng Saen Town; Long term plan: Phnom Penh City,
Takhmao Town and some other towns along the Mekong River and around the Tonle Sap Lake.
•Target Plan
1.The National Program outlines priorities and projects for each sector of the economy. Regarding the physicalinfrastructure, one main priority is said to be linking of the three designated growth poles Phnom Penh, Coastal Zone andSiem Reap. The CZ is a priority not only tourism and also for industrial development, while the areas around Kampot andSihanoukville Town will be target for the wastewater management as a priority.
12

Previous & Ongoing Projects
No.

Project Name

Funding
AgencyLoan Amountfor Civil Works
only

1

Emergency Rehabilitation Project for
Water Supply and Sanitation in
Battambang

EU

Grant (N.A)

2

Provincial Towns Improvement Project,(Part C: Wastewater Management
System, and Part D: Local Governanceand Resource Mobilization, inin Sihanoukville

3

Mekong Tourism Development Project,
Part A1: Siem Reap Wastewater
Management System

ADB LoanNo.: 1725 CAM (SF)and 2013 CAM (SF)ADB LoanNo.: 1969 CAM (SF)4Siem Reap Urban Development Project
Drainage & Wastewater Master Plan
Study, Priority Works
Siem Reap Sewerage System andImprovement of Siem Reap River

5

6
7

8
9

Project Cover Area

Loan
Agreement
Year

Completion
Year

East Part of Town
Center about 200 ha.

1992

1994

USD 11.19 M

Cover an area of 221.5
ha with 3,368 service
connections

02 Feb. 2000

31 March 2007

USD 14.37 M

About 530 ha

7 Feb. 2003

31 Dec. 2009

AFD,
FrenchGrant:US$4M

East Part Siem Reap
Town Drainage

2008

2009

Korea
Eximbank

USD 26 M

Cover total area of 934
ha (East 365ha+ West569ha)

2011

2014

GMS: Southern Economic Corridor
Towns Development
Integrated Urban Environmental
Management in the Tonle Sap BasinADB

USD 55 M

Cover 4 Corridor Towns

2014

2018

ADB

USD 52 M

2016

2021

GMS: Second Corridor Towns
Development
Provincial Water Supply & Sanitation
Project

ADB

USD 38 M

2016

2020

ADB

USD 30 M

Cover Pursat &Kampong Chhnang
Town
Cover Kampot &Sihanoukville Town
Battambang, Pursat,
Svay Rieng & Kampong
Thom

2017

2022

13

Sihanoukville Wastewater Management

14

Sihanoukville Wastewater Management
Wastewater treatment plant was constructed in may 2003 under ADB loan andcompleted July 2005. The wastewater unit is currently operated under theadministration of department of public works and transport and financial
management is under the Ministry of Public Works and Transport and Ministryof Economy and Finance in the form of semi-autonomous entity.
Sewage collection system: 65.80 Km
7.348 Km of trunk,
6.126 Km of collector sewer lines
42.165 Km of main lateral
10.1 Km branch lateral lines for 3,344 service connections.
The system covers an area about 221.5 ha and serves about 30,000 people
partly in Sangkat 1,2 and 4 of Prah Sihanouk City, Prah Sihanouk Province plus
1,200 m3/day wastewater from brewery (CAMBREW).The System is Separate
System .
Sulfide generation about 300 mg/L BOD5 at 30oC, effective BOD5 of about
738 mg/L. Slope requirements is 1.25 times the values for and effective BOD5
of 500 mg/L. All sewer components be protected from sulfide related corrosion.
The sludge is keep to dry on free surface area after that are collected out for
the agriculture using.
15

Siem Reap Surface Water Quality
Parameter
Date
pH
TSS
TDS
BOD
COD-CrDO

Siem Reap River
1
2
3
February 2004
6.07
6.17
5.71
58.9
31.2
42.5
1.4
15.1
5.7

3.6
7.8
3.9

6.1
15.7
3.7

Sampling Location
Canals & ponds
4
5
6
7
July 2004
6.83
7.15
6.70
6.74

8

9

6.95

6.90

540
195
457

270
42
81

240
40
624

460
73
139

660
260
550

990
186
398

Quality Standards: pH, 6.5-8.5; TDS, 200; TSS, 25-100; BOD 1-10; COD-Cr, 1-8; DO, 2-7.
Values shown in bold font indicate non compliance. Shaded locations and values are for the TCD.
Notes: All values in mg/l except pH
Data abstracted from Application for Grant Aid from the Japanese Government (undated)

16

Siem Reap Wastewater Management
Service Area
Existing ADB Area
Areas with high population density
Water Supply area

West

Areas with a large concentration of
hotels and tourism activity

ADB

District

ADB

EXIM

Total

264 ha

1,083

West

264 ha686 haEast-

397 haEast

17

Siem Reap Wastewater Management

Legend :1.Guard House
2. Parking
3. Administration Building
4. Workshop
5. Generator House
6.Washing Facilities
7.Inlet Structure
8.Outlet Structure
AP1 Anaerobic Pond 1
AP2 Anaerobic Pond 2
SDB Sludge Drying Bed
FP1 Facultative Pond 1
FP2 Facultative Pond 2
MP1 Maturation 1
MP2 Maturation 2……. Forced Main Server_____ Process Flow18

Siem Reap Wastewater Management
Wastewater treatment plant was constructed in June 2007under ADB loan
and completed December 2009. The wastewater unit is currently operated under theadministration of department of public works and transport and financial
management is under the Ministry of Public Works and Transport and Ministry of
Economy and Finance in the form of semi-autonomous entity.
The treatment plant operated by natural gravity flow . Sanitary and storm
sewers come from public go to pumping station ,capacity 14,000m3 per day and to 6
difference pond system which the operation system as mention bellow :- two anaerobic pond
- sludge drying bed- two facultative pond
- two large maturation pond which size is totally 120,000m2.Please see theattached photos.
The treatment capacity is 3000m3 per day , cover area 264 hectares in areas
with high population density. The water quality percentage from treatment plant isabout 60 to 80 %.

19

Siem Reap Sewer Flow Process
Improving Flow ConditionWC
To install Sewer

Existing Sewer
Town Center Drain
Weir Board

Resettleme
nt Area
Wastewater
Treatment Plant

Force main Sewer

Pumping
StationRice Field

Wastewater Generation by both districts
Description

2010

2015

2020

2025

2030

East

3,915

4,907

6,049

7,379

8,909

West

7,484

9,250

11,31013,716

16,526

Total

11,39914,157

17,35921,09525,43520

Siem Reap Sewerage System
Wastewater Generation by both districts(Unit : m3/d)
Description

2010

2015

2020

2025

2030

East

3,915

4,907

6,049

7,379

8,909

West

7,484

9,250

11,31013,716

16,526

Total

11,39914,157

17,35921,09525,435West

ADB

Proposed Construction Plan by Phase

East• West one can cover almost of wastewater
generationfrom the west until 2030.
required)(9,000m3/day extension
Description
2020
2030
Capacity
9,000• East (mis3/d)
required6,000
to build a new
WWTP.

Remark36ha

SR Waste Stabilization Pond System

Phnom Penh Present

21

Phnom Penh in 202022

Phnom Penh Surface Water Quality
Sampling Location
Water quality
BOD

SS

COD

T-N

T-P

1

103.2

183.0

56.1

38.8

4.0

2

24.6

32.5

23.4

15.5

1.6

3

27.3

68.0

24.0

20.6

2.3

4

26.7

67.0

25.3

19.3

2.1

5

147.6

142.0

54.1

30.9

3.3

6

110.4

56.0

52.2

40.8

4.1

1
2
6

3

5
4

Sampling date : 2010.08.08

23

7- Issues and challenges
The present situation of sewerage and drainage is alarming,
flooding during the raining season, climate resilience andrequires urgent intervention to address the issues;
A further deterioration is expected through rapid town
development, land use & zoning development and the basic
infrastructures (flood protection, water flow regulation system,
town center drain, diver channel…);
At present, there is no sewerage and drainage sector masterplan for the towns or country,
Not adequate human resources, empowerment and financial
resources for O&M and management of the sewer system;24

Necessary Countermeasure• Establishment of legislation and laws for wastewater
management institutions for the empowerment/ enforcement,
Capacity building and resources mobilization.
• Master plan for the wastewater management & related basic
infrastructure of each urban area and towns throughout thecountry is urgently required;• Encouragement of private sector to participate.
• People awareness to importance of wastewater management.

25

Thank you