2.1 Cambodia
1 | Country Information
Table 2.1.1 Basic indicators
Land Area (km2)

181,035 (2013)*

Total Population

15,288,489 (2019)*

GDP (current USD)

27.08 billion (2019)**
1,643 (2019)**

GDP per capita (current USD)
Average Precipitation (mm/year)

1,840 (1901–2016)***

Total Renewable Water Resources (km3)

476.1 (2017)

Total Annual Freshwater Withdrawals(billion m3)

2.184 (2017)

Annual Freshwater
Withdrawals
by Sector

Agriculture

94% (2017)

Industry

1.51% (2017)

Municipal(including domestic)

4.48% (2017)(Source: FAO 2020, *Ministry of Planning 2019, **World Bank 2020a,***World Bank 2020b)

Figure 2.1.1 Tonle Sap Lake

2 | State of Water Resources
Cambodia is located in the middle reach of the Lower
Mekong Basin and 86% of its land area, including Tonle
Sap Lake (TSL), drains into the Mekong River (FAO 2020).
The floodplains, TSL, and the Mekong Delta are the major
sinks of sediments and nutrients, which are essential foraquatic ecosystems and agriculture. The Mekong-TSL is
one of the world’s unique aquatic ecosystems, in thathigh flow conditions of the Mekong River in the wet
season induces reverse flow through the TSL River into
the lake. Due to the reverse flow as well as runoff fromtributaries around the lake, the TSL transforms in sizeby six times on average, reaching approximately13,000
km 2 with an average depth of 8–10 m (TSA 2015).

32

In the subsequent dry season, water draining out of
the lake is critical for the overall flow condition in thedownstream Mekong Delta. The Bassac River splits fromthe mainstream Mekong River and further splits into
numerous channels, forming a wedge shaped delta in
Vietnam. The Mekong Delta is a major grain basket for
both Cambodia and Vietnam. This distinctive hydrologicalcycle and associated sediment and nutrient regime isvital for aquatic biodiversity, including migrating fish, andTonle Sap Lake forms the sole source of livelihood forabout 40% of Cambodia’s population (MRC 2010).
Cambodia has an ample supply of water, mainly from
the Mekong River, Tonle Sap River, Bassac River andother tributaries, but most parts of the country
encounter water shortages during the dry season,
especially for domestic and irrigation uses. Water in
Cambodia remains regulated only in part, resulting in an
overabundance of water during the rainy season anddeficiency in the dry season.
Groundwater availability is estimated at 17.6 billion
3m (MoWRAM 2012), which is primarily used forhousehold water supply, irrigation and industry.
Groundwater use is increasing by 10% every year, andmany places in Cambodia have experienced overuse ofgroundwater due to rapid population growth andincreasing demands from agriculture and industry (UNDP2020); for example, an average groundwater level declineof 14 cm per year was reported for wells in Prey Veng andSvay Rieng between 1996 and 2008 (Johnston et al. 2013).

3 | State of Ambient Water Quality
3.1 Rivers
The water quality of rivers was assessed as good andwater pollution is not considered to be a significant
problem (MOEC 2020). However, in recent years
water quality deterioration has been reported in riverwater bodies. Water quality monitoring conducted by
Department ofWater Quality Management, Ministry ofEnvironment of Cambodia (MOEC) at the Chroy Changva
Station of the Mekong river showed a rising trend
in nutrient pollution in river water since 2011 (Figure
2.1.2). Although concentrations of total nitrogen (T-N)
remained below the national standard value, it exceeded
the national standard value in 2018 and 2019. Total
phosphorus (T-P) concentrations exceeded the national
water quality standard from 2012 to 2019. However,
Biological Oxygen Demand (BOD), and Chemical Oxygen

Chapter 2: Country Profiles of Water Environmental Management in WEPA Countries

BOD (mg/L)

10.0

BOD std.

10.0

COD (mg/L)

4.0
2.0

2011 2012 2013 2014 2015 2016 2017 2018 2019
T-P (mg/L)

T-P Std.

T-P (mg/L)

0.60
0.40

Japan

0.15
0.10

0.00

2011 2012 2013 2014 2015 2016 2017 2018 20192011 2012 2013 2014 2015 2016 2017 2018 2019

Figure 2.1.2 Water quality of Mekong River at Chroy Changva Station (Source: MOEC 2020)

3.2 Lakes and Reservoirs

BOD (mg/L)

10.0

BOD std.

COD (mg/L)

4.0

0.0

2011 2012 2013 2014 2015 2016 2017 2018 2019
T-N (mg/L)

0.18

T-N Std.

0.16
0.12

T-P (mg/L)

0.14

1.20
1.00
0.80
0.60

0.08
0.06
0.02
0.00

2011 2012 2013 2014 2015 2016 2017 2018 2019

Viet Nam

0.04

0.20
2011 2012 2013 2014 2015 2016 2017 2018 2019

T-P Std.

0.10

0.40
0.00

T-P (mg/L)

Thailand1.40

2011 2012 2013 2014 2015 2016 2017 2018 2019

Sri Lanka

T-N (mg/L)

4.0
2.0

2.0

1.60

6.0

Philippines

BOD (mg/L)

6.0

1.80

COD std.

8.0

8.0

0.0

COD (mg/L)

Nepal

10.0

Myanmar12.0

Malaysia

Tonle Sap Great Lake (TSL) is the largest freshwater lake
and a unique flood-pulse in Southeast Asia. It covers an
area of 13,000 km2 during the rainy season and shrinks
to 2,500 km2 during the dry season. About 1.7 million
people live in 1,037 fishing villages of TSL and surrounding
floodplains and their livelihoods directly depend on TSL’s

resources (Shivakoti and Bao 2020). However, due todegradation of the TSL water environment, caused by
the inflow of anthropogenic pollutants, the livelihoodsof millions of local residents is affected (Ung et al. 2019).
Water quality in TSL was monitored by the Department
ofWater Quality Management, MOEC at the Chhnok
Trou village from 2011 to 2019, and also revealed
deterioration of water quality of TSL (Figure 2.1.3).
According to the monitoring data, both BOD and COD

Lao PDR

Demand (COD) values imply that organic pollution is low.

Republic of Korea

0.05

0.20

Indonesia

T-N (mg/L)

2.0

0.20

T-N Std.

0.80

0.00

4.0

0.0

2011 2012 2013 2014 2015 2016 2017 2018 2019
T-N (mg/L)

6.0

China

BOD (mg/L)

6.0

1.00

COD std.

8.0

8.0

0.0

COD (mg/L)

Cambodia

12.0

Figure 2.1.3 Water quality of Tonle Sap Lake at Chhnok Trou village, 2011–2019 (Source: MOEC 2020)33

values remained well within the national water quality
standard for lakes, which implies organic pollution is nota major issue for water environment management in TSL.
In contrast to BOD and COD, concentrations of T-N and
T-P exceed the water quality standard for most of themonitoring period, which indicates TSL water could behighly polluted by agricultural pollution such as runoff offertilizer, manure, which can also derive from householdproducts such as soap and detergent.

3.3 Coastal Water
Cambodia’s coastal shoreline is 435 km long on the
Gulf of Thailand, and the seaward boundary of thecoastal zone has been delimited as the outer limit of
the country’s exclusive economic zone with an area of
55,600km2. The landward boundary of the coastal zone
has not yet been satisfactorily defined, but is currently
considered to be about 5 km from the shore. The coastal
zones are situated in the four provinces of Koh Kong,
Kampot, Sihanoukville and Kep municipalities. In general,
coastal water is considered to be of fairly good quality,
but development activities such as those in economic
zones and seaports may exert a negative influence
on coastal water and coastal ecosystems if soundmanagement of solid and liquid wastes generated fromthose activities has not been properly implemented.
According to the results of monitoring in 2018,
concentrations of T-N, T-P and oil and grease exceeded
the national water quality standard for coastal water,which indicates anthropogenic activities are the mainthreats for the coastal water environment.
2.5

mg/L

1.5
1.0
0.5

Monitored
conc.

water quality
standard
T-N

Monitored
conc.

water quality
standard
T-P

Figure 2.1.4 Coastal water quality in Kep Municipality, 2018

(Source: MOEC 2020)

3.4 Groundwater
Groundwater in Cambodia is generally of good quality,and dependency on groundwater as a source of domestic
water is as high as 62–100% (MoWRAM 2008). However,high levels of arsenic, iron, manganese, fluoride, and total
dissolved solids (salinity) are observed in some areas(UNDP 2020). Arsenic concentrations in groundwater34

4 | State of Wastewater Treatment
Sewerage and sanitation in Cambodia are not welldeveloped and types in existence are aging or
constructed in the old colonial period. In most places,
wastewater is primarily treated by septic tanks anddischarged to the environment. As of 2019, only three
centralized wastewater treatment plants (CWTPs) are
under operation, located in Battambang City, Siem Reap
City and Preah Sihanouk City (Rady 2020). Further,
Phnom Penh has natural lagoons that receive wastewaterfrom the drainage system. The current centralized
WWTPs can treat only 5% of urban wastewater (Heng2019). Monthly service fees have been collected by
the Department of Public Work and Transport for thecentralized wastewater treatment facilities, such as inPreah Sihanouk City, where fees of 2.5 to 1,125 USD arecollected per building based on building category.
Cambodia has prioritized the development ofsewerage systems and centralized wastewater treatment
in several locations, and the urban wastewater
management plan has selected priority towns for future
centralized WWTPs in Cambodia (Table 2.1.2). In addition
to centralized systems, NGOs such as ESC-BORDA
promote decentralized wastewater treatment solutionsin schools, communities, hospitals, and small andTable 2.1.2 List of existing and future centralized
wastewater treatment plants

2.0

0.0

in many parts of Cambodia exceeded both the WHO
standard of 10 mg/L and the Cambodia National Drinking
Water Quality Standard of 50 mg/L. Many shallow wells
are also contaminated by fecal coliforms (IWMI 2013).

Location ofCentralized WWTPs

Capacity(m 3/day)StatusBattambang city

2,800

In operation

Siem Reap City

8,000

In operation

Preah Sihanouk City

25,000In operation

Poipet City

3,000

Feasibility study

Srei Saophoane City

3,000

Feasibility study

Kampot City

6,000

Feasibility study

Kep City

3,000

Feasibility study

Phnom Penh

30,000Feasibility study

Takhmao City

12,000Feasibility study

Pursat City

6,000

Feasibility study

Kratie City

6,000

Feasibility study

Steung Sen City

3,000

Feasibility study

Bavit city

3,000

Feasibility study(Source: Heng 2019)

Chapter 2: Country Profiles of Water Environmental Management in WEPA Countries

The current legislative framework for water
environment management in Cambodia is shown in
Figure 2.1.5. Under it, the protection and promotion ofenvironmental quality and public health is the objective

Indonesia

5.1 Legislation

China

5 | Frameworks for Water
Environmental Managementof natural resource management including water(Article 1, Law on Environmental Protection and Natural
Resource Management). The Law on Water Resources
Management (2007) includes aspects of water quality
management, such as requiring wastewater discharge
licenses or permission for activities that could havenegative impacts on water quality and human andecosystem health (Article 22), as well as designations
for dangerous or restricted zones for water use where
the water quality, quantity and ecological balance areendangered (Article 23).

Cambodia

medium-sized enterprises. To date, ESC-BORDA has
implemented 62 DEWATS across Cambodia (BORDA
2017).

Japan

Law on Water Resources Management (2007)

Sub-decree on Environmental Impact
Assessment Process (August 11, 1999)

Purpose-regula�ng water pollu�on control for preven�ng andreducing the water pollu�on of public water bodies.
Sub-decree on the Management of Sewage andWastewater Treatment System (December 25, 2017)

Thailand
Viet Nam

under the Law on Environmental Protection and Natural
Resources Management, such as the Sub-decree on Solid
Waste Management and the Sub-decree on Environmental
Impact Assessment Process, also contain articles related
to water environmental conservation.
Currently, two new pieces of legislation are being
drafted in relation to water quality management, namely
the Law on Sewerage System in Cambodia by Ministry of
Public Works and Transport (MPWT) and the Sub-decree
on Water Quality by the Ministry of Water Resources andMeteorology (MoWRAM). The sub-decree on Water
Pollution Control (April 6, 1999) is being updated toreflect the context of Cambodia.

Sri Lanka

Details on water environmental conservation
measures can be found in the Sub-decree on Water
Pollution Control, established in 1999 under the Law on
Environmental Protection and Natural Resources
Management. This sub-decree aims to regulate various
activities that could pollute and/or have already polluted
public water areas (e.g., rivers, lakes, groundwater, andsea water). Ambient water quality standards for humanhealth and bio-diversity (Article 7), as well as effluent
standards for pollution sources (Article 4) are set by thissub-decree. Other elements of the sub-decree include
monitoring of pollution sources and their effluents(Chapter 4), monitoring of public water areas (Chapter5), and inspection rules (Chapter 6). Other sub-decrees

Philippines

Figure 2.1.5 Legislative framework of water environment management in Cambodia

Nepal

Purpose-improving the drainage system management and wastewater
treatment plants in eﬀec�ve and transparent way to ensure
safety of public health and biodiversity conserva�on.

Myanmar

Purpose-regula�ng solid waste management in an appropriate
and safe way to ensure the protec�on of humanhealth and the conserva�on of bio-diversity.

Sub-decree on Solid Waste Management (April 27, 1999)

Malaysia

Purpose-regula�ng water pollu�on control for preven�ng andreducing the water pollu�on of public water bodies.

Lao PDR

Sub-decree on Water Pollu�on Control (April 6, 1999)

Purpose-protect and promote environment quality and public health-assess the environmental impacts-ensure sustainable use and management the natural
resources-encourage and provide possibili�es for the public topar�cipate in the protec�on of environment and the
management of the natural resources, and-To suppress any acts that cause harm to the environment.

Republic of Korea

Purpose-s�mula�ng the eﬀec�ve and sustainable managementof the water resources to a�ain socio-economic
development and the welfare of the people.

Law on Environmental Protec�on andNatural Resources Management (1996)35

5.2 Institutional Arrangement
In Cambodia, several ministries deal with water
environment management (Table 2.1.3). MOEC is
responsible for protection and management of theenvironment and natural resources in the country basedon the Law on Environmental Protection and Natural
Resource Management (Article 9), and local authorities
such as provincial and municipal environmental
departments are in charge of water environmental

management, such as water quality monitoring.
MoWRAM was established in 1999 as lead water sector
agency, and exercises overall responsibility for water
management and conservation including Integrated
Water Resource Management (IWRM). Ministry of PublicWork and Transport is responsible for urban wastewater
management. Other important agencies include Ministryof Industry, Mine and Energy (MIME), and Ministry of
Rural Development (MRD), Tonle Sap Authority (TSA).

Table 2.1.3 Institutional arrangement of water environment management in Cambodia
AgencyResponsibilities

Ministry of Environment (MOEC)- Assess the environmental impact (EIA) of all existing and proposed projects/activities(Article 6)- Research and assessment of environmental impacts on natural resources (Article 9)- Provide recommendations to other concerned ministries to ensure conservation andrational use of natural resources (Article 9)- Develop inventories of pollution sources (Article 12)- Develop sub-degrees to prevent and reduce pollution (Article 13)- Monitor pollution sources and natural resource development activities (Article 14)- Conduct inspection of pollution sources (Article 15) and order improvement forviolations (Article 20)

Ministry of Water Resources and Meteorology(MoWRAM)- Water management and conservation through Integrated Water Resource
Management (IWRM)

Ministry of Public Work and Transport (MPWT)- Urban wastewater management

Ministry of Industry, Mine and Energy (MIME)- Drinking water supply for cities and towns

Ministry of Rural Development (MRD)- Clean water supply for rural areas

Tonle Sap Authority (TSA)- Coordinate management, conservation, and development in Tonle Sap area andrelevant areas

5.3 Ambient Water Quality Standards
Ambient water quality standards

Ambient water quality standards for public water areas
are set by the Sub-decree on Water Pollution Control(April 6, 1999). There are two kinds: the first covers
biodiversity conservation, which is designated for rivers(five parameters), lakes and reservoirs (sevenparameters), and coastal water (seven parameters); andthe second covers public health, which designates
standard values for 25 parameters related to harmful
effects on human health. These water quality standards
will also be revised through amendment of the subdecree on Water Pollution Control. There is no
groundwater quality standard, but water quality isassessed by standards designated for specific uses, suchas national drinking water quality standards.

36

Water quality monitoring framework
Since the promulgation of the Sub-decree on Water
Pollution Control in 1999, MOEC has been responsible
for regular control and monitoring of water pollution
in public water areas throughout Cambodia. MOEC
monitors river water quality at seven points, coastal
water quality at seven points and lake water quality atthree monitoring points every month. Water quality
is analyzed at MOEC laboratories. Further, under the
Mekong River Commission Water Quality Monitoring
Network Program, MoWRAM measures water quality
monthly at designated stations in rivers and related
tributaries. Details of the water quality monitoring
framework are shown in Table 2.1.4.

Chapter 2: Country Profiles of Water Environmental Management in WEPA Countries

Item

Surface water: pH,
Total suspended solids(TSS), CODMn, BOD,
Chromium (Cr6+), T-N,
T-P

T °C, pH, EC, Alkalinity/
Acidity, DO, COD, BOD,
T-P, T-N, NO3-N, NH4-N,
Feacal coliform, TSS,
Calcium, Magnesium,
Potassium, , Sulfate(SO42-), Chlorine

Sea: pH, CODOH,
Dissolved oxygen,
Coliform, Oil & Grease,
T-N, T-P

19

Frequency ofmonitoring

MonthlyMonthlyFrequency ofmonitoring
report published

Quarterly-

5.4 Effluent Standards
Effluent standards

Myanmar
Nepal
Philippines
Sri Lanka
ThailandUnder the Sub-decree on Water Pollution Control, allbusiness operators are obliged to self-monitor effluent
and submit periodic reports of results to MOEC. However,as some do not, MOEC conducts regular on-site
inspections to check whether they are in compliancewith effluent standards, which involves taking andanalyzing water samples of effluent as well as treated

Malaysia

Effluent inspection procedure

The major ways in which Cambodia has responded todate have been legislative, in the form of pollution related
decrees and laws, creation of an institutional framework– especially under MOEC and MoWRAM – as well as
introduction of monitoring and enforcements. One such
response is the National Water Resource Policy for theKingdom of Cambodia, developed by MoWRAM in 2014.
Its main objectives are: ( i ) protect, manage and use
water resources in an effective, equitable and sustainable
manner; (ii) solve water issues in collaboration withrelated institutions within public and private sectors;(iii) develop and carry out the national strategy andpolicy towards water resource management; (iv) direct
stakeholders for developing, managing and utilizing water
resources; and (v) achieve the national policy objective
on poverty reduction and sustainable national economy
development. The Cambodia National Environmental
Action Plan (NEAP) 1998–2002 is the first environmental
action plan initiated by MOEC to develop and implement
to integrate environmental concerns as well as decisionmaking processes of various stakeholders into national
policies. NEAP incorporates issues relevant to the water
environment from the viewpoints of fisheries, Tonle Sap
Lake, wetlands, public health (water borne diseases), as
well as minimizing environmental impacts from energy
industries (hydropower, oil and gas industries).

Lao PDR

Aiming at managing effluents discharged from pollution
sources, the Effluent Standard for Pollution Sources
Discharging Wastewater to Public Water Areas of Sewers
was established under the Sub-decree on Water Pollution
Control. Standard values are set for 52 parameters, suchas temperature, pH, BOD, heavy metals, agriculturalchemicals, and organic solvents. In principle, thestandards are applied to all industries and other pollution
sources designated by the sub-standards. For areas
which require special treatment for protection of humanhealth and biodiversity, MOEC can establish separate
effluent standards for pollution sources in the area
(Article 5 of the sub-decree). As mentioned in section
6.1.1, the Sub-decree on Water Pollution Control is being
updated to reflect the context of Cambodia. The effluent
standard will be updated through amendment of the
Sub-Decree on Water Pollution Control.

5.5 Major Policies on Water Environmental
Management

Republic of Korea

17

When violations of effluent standards are found, MOEC
issues written orders to industries to correct current
activities in order to be in compliance with the standards.
Industries are fined and punished for violations in themonitoring and reporting of, and compliance with
effluent standards stipulated under the Sub-decree on
Water Pollution Control for failure to act on orders issuedby MOEC.

Japan

Number ofsampling points

Measures against non-complianceIndonesia

MoWRAM

China

Name ofmonitoring
parameters

MOEC

water. Two types of monitoring programs are in place atpollution sources: (i) regular effluent monitoring at
normal factories and hotels, conducted at 90 day
intervals, and (ii), regular effluent monitoring at factories
that use chemicals and/or chemical compounds for
production, which should be conducted at 45 day
intervals.

Cambodia

Table 2.1.4 Water quality monitoring framework of MOEC
and MoWRAM

Viet Nam37

6 | Recent Developments inWater Environmental Management

5. Barriers to appropriate management of water
quality due to insufficient equipment forlaboratory/field testing

There are several developments in government policies
that will have significant impacts on water environment
management, as follows:

6. Shortage of expert technical officers at national
and local levels to carry out adequate water
quality management and enforcement

i. Sub-decree on Management of Sewage andWastewater Treatment System, enacted on 25
Dec. 2017, which provides a mandate formanagement of sewage systems and wastewater
treatment systems to sub-national authorities.

7. Budget limitations of government, especially for
improvement of capacity of laboratories in termsof facility infrastructure/equipment and humanresources

ii. Development of draft Environmental Code (ENRC),
which consolidates several existing legislative
arrangements for environmental protection andconservation of natural resources, including
provisions for waste and pollution control andimplementation of SDGs.
iii. Development of draft Sub-decree on selfmonitoring and report, which aims to enhancemonitoring of high potential pollution sources by
installation of real-time online monitoring
equipment and regular reporting to MOEC.
iv. Updating of Sub-decree on Water Pollution
Control, which is to include revisions of water
quality standards and effluent standard.

7 | Challenges and Future Plans
Based on the current state of water quality managementin Cambodia, several key management challenges havebeen identified, as follows:
1. Lack of specific water quality management policy
and strategies
2. Weak inter-ministerial coordination for water
environment management
3. Improvement of human resources and institutional
capacity, especially MOEC, in order to implement
Cambodian Sustainable Development Goals
framework (CSDGs), National Environment Strategy
and Action Plan (NESAP) and ENRC
4. Development of sewers and wastewater treatment
to deal with drainage problem and pollution ofwater bodies; Master plan for sewerage anddrainage sector for towns/country also required38

In order to overcome these challenges the following
actions will need to be taken by the line ministries andagencies:
i. Initiation of development of the National Water
Quality Management Strategies by MOEC
ii. Strengthening collaboration with other countries
for capacity development on water quality
monitoring and enforcementiii. Enhancing cooperation with development
partners to construct planned central sewage
treatment plants in priority cities
iv. Establishment of inter-ministerial coordination
mechanisms, to enhance cooperation among line
ministries such as Ministry of Environment,
Ministry of Water Resources and Meteorology,
Ministry of Agriculture, Forestry and Fisheries,
Ministry of Mines and Energy, and Council for theDevelopment of Cambodia towards soundmanagement of water environment in Cambodia