Establishing a surface water quality monitoring network
for the Mekong delta,Viet Nam 1
PROPOSAL ON
ESTABLISHING A SURFACE-WATER QUALITY MONITORING NETWORK
FOR THE MEKONG DELTA, VIETNAM

prepared by
College of Technology, CanTho University, Vietnam
(Version 22 July 2004)
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I. INTRODUCTION AND RATIONALE
1.1 The Mekong Delta and its main environmental problem
Mekong River, the 11
th
largest river in the world, is the main water source for irrigation, fishery,
and domestic use… In short, the living of the whole population in the Mekong Delta (MD) is
depending and will be depended on this resource.

2000).

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Surface-water quality problems are classified according to natural conditions due to topography
and geology of the delta. The development of the delta at the moment and in the near future,
beside positive impact, will also lead to environmental pollution. Development of agricultural
sector and urbanization are main issues affect the water quality. Use of excess and improper of
fertilizer leads to enrich water body by nutrients together with poor drainage in impression areas
in the MD, will impair water quality. Trophic state of water body at present is in hypertrophic
level; in addition the use of pesticide, fungicide, insecticides is not controlled. Most of micro-
organic pollutants are DDT, DDE, Dieldrin…
Rapid urbanization in some rural areas, combined with backward behaviors as making on the
canal overhung latrines, directly discharge of domestic wastes to canal system without any
treatment and others cause oxygen deficiency in water body.

1.2.1 Problems on water quantity
1. Shortage of fresh water for irrigation in the dry season
In 1999, a total area of 1.4 millions ha of spring-rice crop (dry season crop) needs irrigation.
Water demands are increased proportional with rice cultivation areas. From 1995 to 1999, newly
reclaimed areas available for rice cultivation has increased by 105.000 ha/year (Statistical
Yearbook 2000).
The main thrust of water resources development may be on-farm development and canal
improvement (enlargement of existing, and construction of new primary and secondary canals)
to bring more irrigation water to the already irrigated areas and to improve drainage conditions
and promote flushing of acid water. Embankment improvement in the deeply flooded areas could
prevent flooding till the end of August. In the shallow flooded, already more developed areas;
full year round protection is possible.
Both rainfall and river flow have a pronounced seasonal patterns. Periods of water excess
alternate with periods of water shortage, and water control measures must essentially adapt to
this regime feature. Virtually the only source of water for irrigation is the Mekong River, which

Acidification of canal water is a problem in areas with large concentrations of acid sulfate soils;
especially during May ÷ July when the acids from the soil enter the canals with drainage of the
early rains. Acidification of canal water can in general be managed by providing adequate
through-flow in the effected area, but as reclamation of acid sulfate soils progresses this may not
longer hold true.
The subsoil of the MD contains huge quantities of groundwater. Its exploitation, however, is
constrained by 3 factors: (1) the quantity of the water in the five aquifer, mainly salinity, (2) the
permeability of the aquifers, and (3) the fresh water recharge of the aquifers, which determine
the safe yield. However, when considering the expected urbanization in the MD, this quantity is
actually small. It should therefore be reserved for urban and rural water supply use only,
predominantly for rural areas and town that cannot avail of good quality surface water.

1.2.2 Problems on water quality
1. Acid sulfate soils
In large parts of the MD, clayey sediments deposited under brackish or saline conditions contain
soluble sulfates. In these, sulfate-reducing bacteria convert the sulfate to sulfides under anaerobic
conditions. This result in the formation of hydrogen sulfide – a highly toxic gas – and iron
sulfide, pyrites, FeS
2
, an insoluble non-toxic compound.
Acid sulfate soils, form when soils containing iron sulfide are exposed to oxygen, cover 1.6
millions ha (40%) of the MD (Minh et al. 1996). Soils with high iron sulfide content do not
usually become a problem so long as the soil remains inundated (Brinkman, Ve, et al. 1993).
Agricultural activities in the acid sulfate soils, especially in the large scale in the 2 severely acid
regions, Plain of Reeds and Long Xuyen Quadrangular (with a total surface area of more than 1
million ha), major cause of water pollution in the region.
The most significant detrimental properties of acid sulfate soils are:
• Release of acid (and sometimes toxic) drainage water which causes detrimental impacts
on the environment downstream.
• Fixation of phosphorus in the form of insoluble aluminum or iron phosphate. This locks

animals and plants that have accumulated pathogens from the water in which they live. Shellfish
grown in polluted waters are particularly liable to infect consumers, since they filter large
volume of water in feeding and may be consumed raw or after insufficient cooking.
During the dry season, there is in many areas in the delta a serious lack of drinking water. The
water quality of the surface-water of the delta has a tendency to get worse when going
downstream. Because of rapid urbanization in the Delta that leads to high population densities.
The low basic sanitary condition, in form of overhung latrines above public channels and
fishponds it is expected that the surface-water contain high concentrations of fecal coliform
bacteria. Most of wastewater is diverted directly into the rivers and the canals. In addition,
people living along the rivers and the canals or in boats dispose solids and liquid waste into the
water. Besides, feeding fish by night soil in the fishponds connected to the rivers or canals is a
popular economic source which makes the surface-water contaminated. As many people in the
area drinks straight from the surface water, enteric infections and diarrhea diseases are widely
spread in the area.
If appropriate measures are not taken to reduce the discharges of domestic waste products into
the ambient environment, then probably the capacity of the nature to decompose and turnover
these waste products will be exceeded in the near future. This assumption is based on the
dramatically increase in the growth of population in the past 20 years. The development of the
MD in the near future is expected in high rate in which urbanization will cause serious
degradation of water quality.

4. Organic pollution

Besides causing aesthetic water pollution problems, dumping or discharge of organic matter into
receiving water bodies also creates oxygen deficiency. After being discharged into the water the

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organic matter starts decomposing. This process is oxygen consuming and temperature
dependent and the high temperature in the Mekong River system all the year around will
accelerate this process. If the receiving water bodies do not have the oxygen renewal capacity

In all estuaries, the relatively short zone in which the fresh/saline water interface ebbs and
follows with each tide represents an efficient “nutrient trap”, in which many minor chemical
contaminants become concentrated. Because of the uncertainty of the actual active ingredient
concentration of these materials, and the poor records of their use, no reliable data on the
potential risks to the general inland environments can be calculated. There is an urgent need for
monitoring their presence in the estuarine nutrient trap zones, since their effects on communities
in this zone may be far more significant than in many other habitats.

6. Hazardous substances pollution

Dumping of solid waste products in landfills will always create a potential risk of leaching of
environmentally hazardous substances and contamination of groundwater and surface waters.
Discharge of industrial wastewater which contains toxic substances and accidental spill of
chemicals during transportation may result in serious environmental pollution. Toxic substances

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that will accumulate in the environment, such as certain metals, pesticides and other organic
substances resistant to bio-degradation, require particularly cautious regulation since their effect
may be irreversible or present hazards to consumers of the water, i.e. for drinking or aquatic
organisms.
At present the MD is not detrimentally impacted due to discharges of industrial waste products.
However, in near future with rapid development in the region, this should be taken into
consideration, the responsible environmental authorities has to establish an industrial
management plan aiming at protection the environment against industrial discharges.
Annually, Department of Science Technology and Environment (DOSTE) of 11 provinces in the
MD organized two campaigns for monitoring surface-water quality. Those activities are useful
when they want to observe about surface-water quality in their basin. In addition, those results
could be used to orient the development of their provinces. However, the results of this campaign
could not be used in the effective way because of the following reasons:
• The sampling and analyzing techniques are varied from province to province.

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III. ACTIVITIES
3.1 Partner coordinator missions to Vietnam
Term of Reference:
• Identification of project feasibility
• Discussion on project management aspects
• Need assessment: expert missions, training subjects, resources, etc.

3.2 Initiative workshop in Vietnam
Target group:
• Leaders, representatives of DOSTEs and Environmental Monitoring Station.
• Staff of CTU who are teaching, doing the research on environmental issues
Experts:
• Experts from partner side
• Experts of CTU

3.3 Training in Vietnam
Topics:
• Sampling methods
• Analyzing methods, especially the ones that are suitable with used equipments.
• Applied GIS to Water Management

3.4 Training in foreign country
2 MSc. in:
• Applied Informatics in Water Quality Monitoring
• Water Quality Management

3.5 Lab equipments
The following equipments need to be equipped for the labs:
pH meter

V. DESCRIPTION OF PARTNER INVOLVED IN THE PROJECT
Foreign partner: ……………………….

Vietnamese partner:
• Project leader: Prof. Le Quang Minh, Vice Rector, Dean (Dr. in Agricultural and
Environmental Science, Wageningen University, Netherlands)
• Coordinator: Mr. Le Hoang Viet, Director, Environmental Engineering and Renewable
Energy Center, Vice dean, College of Technology, Cantho University (MSc. in Environmental
Engineering, AIT, Bangkok, Thailand)
• Member: Mr. Nguyen Hieu Trung, Vice Director, Environmental Engineering and
Renewable Energy Center, Cantho University (MSc. in GIS, International Technology Center,
The Netherlands)
• Member: Mr. Le Anh Tuan, senior lecturer, College of Technology, CTU (MSc. in Water
Resources Engineering, AIT, Thailand)
• Member: Mr. Nguyen Vo Chau Ngan, lecturer, College of Technology, CTU (MSc. in
Sanitary Engineering, Catholic University of Leuven, Belgium)
• Members: representatives of DOSTE of eleven provinces in the MD