AN OVERVIEW OF THE
DRINKING WATER SUPPLY SITUATION
IN THE
Le Anh Tuan, M.Eng. WRE.
E-mail:
latuan@ctu.edu.vn
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I. Introduction
The
As well as many other provinces in
Notice that, in the present time, about 75% of the
inhabitants in the urban and 35% in the suburban and rural have access to clean
water, this figure drops to 20% in far and deep areas. Since last 20 years to
now, many drinking water plants and wells have been built. Most of them are
located in the cities, small towns and suburban. In the deep and far rural
areas, farmers still access water directly from rivers, canals, ponds or shadow
wells.
The Center of Rural Water Supply and
Environmental Sanitation in each province is found since before 1990s and
sponsored by UNICEF initially and Vietnam Central Government later. Their responsible
are to serve clean water for rural people. For urban, there is Provincial Water
Supply and Sewerage Company.
II. Water supply situation
II.1.
Characteristics of water sources
In the MD, water is almost present all over. Water
movement not only defines the biophysical environment of the MD but largely
determines the production options and livelihood strategies of its inhabitants.
For drinking water, there are 3 sources, i.e. rain water, surface water and
ground water. Depending on the location and the periods of the year as well as
the difference living conditions, the people should choice their own-ways for
collecting, storing and treating the water for domestic use.
·
Rain
water: is used as one of
favorite drinking water sources, special in the rural and suburban areas. In
the urban places, rain water seems a minor source besides the tap water. The
quantitative change of annual average rainfall in the MD is among 1,400 - 2,200
mm. About 90% of total rain water falls down the MD from May to October. In the
delta, the dry season extends for 7 months resulting in serious shortage of
rain water supply in many areas (See table 1).
·
Surface water: is considered as a main source for water supply.
Hydrological data records show that, each year, approximately 500 billion cubic
meters (or nearly 15,000 m3/s) have flowed
out to the sea via the delta. High rainfall combined with high flow of the
river results in yearly flooding. Big flood occurs in the
Saline encroachment effects
almost half of the MD. The salinity is caused by sea water intrusion in open
mouths and estuaries. The phenomenon of salinity intrusion in the river
branches is very complicated. The main factors that determine this process are
river discharges, local rainfall and runoff, the tides and the depth of bars in
the sea in front of the estuaries. Otherwise, in early rainy season, nearly 1,6 million hectares of the delta are infected by the acidity
water due to the washing out aluminium and iron
dissolve from the acid surphate soil. Preventation saline water intrusion to depression may cause
a potential acid surphate soil become an activity
acid surphate soil upon drainage and oxidation.
Water quality of the
Data on small streams are scare, water quality however may vary consisderable.
Rapid growths of industrialisation and urbanisation are leaded to increase water demand and also
caused surface water pollution. Some streams flow through provinces/ cities and
towns may be polluted by toxic chemicals at industrial production plants or
domestic used waters, microbiological and biological aspects, insecticides,... There is no
wastewater treatment plant in the city, except some wastewater treatment works
in industrial zones.
The project of fresh-watering the Ca Mau
Peninsula to be invested in enlarging irrigation systems, widening channels and
canals, building drains, dikes, tanks, controlling salted and acid surphate
soil areas in the western and coastal part of the delta for increasing rice
cultivation areas and improving the water supply to the people. So, implementating theses project objectives are to seem
difficulty due to many limited factors, such as capital lacking, environmental
impacts, conflicts between rice farmers and shrimp farmers, project manager's
skill, ...
Operation of water control system may have
some disease incidence caused by altered hydrological regime. Water flow is one
of important factors in transmission of diseases in rural areas. Intestinal
infections diseases including diarrhoea and dysestery occur more generally. Malaria and Dengue fever is
seem common thoughout the delta, especially in backish and stagnant water areas, like Ca Mau, Bac Lieu, Tra Vinh, ...
·
Groundwater: is widely used in the many provinces along the
coastal areas. Source of ground water is plentiful and present all over the
delta. Ground water is exploited and pumped from 2 depth levels: at 80 - 120
meters for household wells and at 400 - 500 meters for groundwater plants (See
Table 2). The upper level water is widely drilled and pumped out. UNICEF pump
is commonly used but the water meet many problems with
salinity and too high iron content. Salt
water infiltration into ground water is very common in the coastal areas in the
MD like Tien Giang, Ben Tre, Ca Mau, Kien Giang, etc. Although a lot of the
wells have experienced quality problems of some kind - pH, high iron content,
salinity and bad smell being most common - almost all plants for the future are
based on increased groundwater withdrawal. The lower level water is
better quality but it is costly in exploitation. Nevertheless, drilling the
well very deep is necessary to be recommended.
II.2. Drinking water collection, treatment and distribution
Depending on the mean, place and time for
water quality and quantity, the
·
Collecting rain water for domestic use is a traditional way in the
MD. Storage of rain water in terra-cotta jars and cement-brick tanks or in
large concrete containers is very common in rural, sub-urban areas and islands.
The advantages of rain water in
the MD are almost clean, purpose, easy to collect and very low cost. However,
rain water is too short in the dry season and its storages are rather
inoculated the mosquito pathogens or insect ovum. Otherwise, when falling from
the air and flowing on the house roofs, arris-gutters
rain water may be polluted by air-dust, bird-guano, ... A few of rain water
analysis have recorded the acidity in the rain water in April, May yearly. No
using of rain water in early rainy season is recommended as way to treat the
air-dust and other pollutants deposited in the house-roofs after a long period
of dry season.
·
Freshwater from river and canal is widely used in the upper parts
of the delta, where the water quality isnot effected
by high concentration of salinity and/or acidity and/or pollution. In An Giang and Kien Giang, building reservoirs in high lands for keeping stream
water is one of the water collection ways.
Commonly,
surfate water taken from the rivers and streams is
settled in settling tanks and then treated by aluminium
sulphate (alum) and sand filter techniques. Finally,
chlorination is used as a disinfectant. The purpose of sand filtration is to
separate solid and liquid mixture. Alum treatment is used commonly in the delta
for decreasing turbidity. This chemical treatment will make surface water more
clarify due to remove total suspended matter. Both sand filter and alum
treatment are effective ways to remove total coliform
bacteria as well. Depending on the special technical and financial conditions,
gravity or pressure filtration, rapid or slow filtration will be chosen. Filter
media are sand (size of 0.2 - 1 mm), gravel, activated coat, porous material or
film are commonly used. Alum has been popular as a
coagulant in treatment processes in the
·
Ground water is the main source for the lower parts of the delta
such as coastal areas and poor water-distribution places. In rural water
supply, the opinion the groundwater is the preferable choice is widespread both
among staff working with water supply and villagers. In the MD, ferrous iron (Fe2+) is found in groundwater
commonly. It cause metallic taste and bad smell.
Groundwater is pumped out and can be treated by aeration and filtration.
Aeration is used to change iron content ferrous to ferric form (Fe3+) and to reduce tastes and odours.
·
Depending on the financial and management capacity, water
suppliers can choice one of filtration processes, such as slow sand filter or
pressure filters or upflow filters. Both surface and
ground water are collected by electricity or hand pumps. Water Supply Plants are governed and placed
in the cities and towns (see figure 3), all are the State-owned water
suppliers. Treated water are stored in water tanks and distributed to
households and other water users by pipe network mainly in cities, sub-urbans and small towns. Only 40 per cent to 50 per cent of the residents in the
Mekong Delta have receive clean water from the State water plants.
According to NEDECO data
sources: The clean water production for 15 towns in the Delta was some 142,000
m3 in 1990, of which some 40% was unaccounted for; ground water took a share of 41,000 m3/day. The urban demand was estimated at 245,000 m3/day. Industrial water use is
estimated at 34,000 m3/day, entirely from ground
water. In the rural area, some 19,500 small wells have been drilled with
an abstraction capacity of 90,000 m3/day
for water supply of about 2.6 million people.
·
In accordance with a decision of Vietnam Government, from 3/2000
and depending on purpose of use, tap water prices were raised by 24.4%
to 69.9%. New prices is listed as table 3. New charges
seem no effect to the high income groups but it is really a problem for the
poor communities.
III. DISCUSSION
Water in the MD is necessary to discuss in all its
aspects. Although the amount of water on the delta is large if compared others
regions on the world, but the capacity of clean water supply is finite in
general and the demand is increasing due to a growing population, industrialisation, urbanisaltion
and living standard.
·
Water
supply is become a potential developing market in the MD. In last ten years, Vietnam Central Government invested US$ 1.3 billion into doubling the nation's
water supply network. Besides the water supply
projects built by the national budget, others are generally funded
through international organisations such as WB, ADB, UNICEF, UNDP and donor
nations such as Finland, Denmark, France, Japan, the Netherlands, Australia,
Sweden, South Korea and Germany. Looking at urban markets anywhere, we can
count more than 20 trade-marks of bottled drinking water. This presents an
increasing of number of drinking water suppliers if compared with a little
number of them in the last decade. Water supply is as planned table 4 and table
5.
·
It
is notice that water loss in water distribution systems is rather high,
especial in the big cities. Up to 40%, even more, of water in Can Tho, Vinh Long, Long Xuyen and Ca Mau were lost through wastage or inefficiency.
Average water loss stands at about 37% in the whole. In whole country, major
causes of unaccounted for water as identified by provincial water companies,
are: leaks in the distribution system; faulty meters and illegal taps (VN Water & Sewerage Ass. 2002), (See figure 4).
·
Pollution
of water both surface and ground had led to a decreasing amount of water
available for use. It really threat the sustainability
of the country if we have no any way and mean to control and to improve. It is
necessary to balance water supply and demand based on the economical/ social/ environmental objectives
of maximizing net benefits of water use.
·
Being poor means limited capital resources to invest in living
standard improvement related to clean water and environment. High prices of
water supply will limit the number of water users in poor households.
·
Decentralised water supply for rural communities is recommended.
Development many small drinking water treatment plants inside or nearby
communes or districts may get a low cost on construction, a simple on
distribution and an easy on management.
·
Environmental
education programmes should be introduced to the
schools, communities widely. Mass communication media should have a role on
raising people’s awareness of water protection also. Others, a guidance how to
save the tap water is also the way to decrease the water demand.
·
Socialisation and privatisation of the
water supply systems should be encouraged and conducted.
·
The
need for international collaboration and donor agencies to support the drinking
water treatment technology, to train the water related staff and to facilitate
cost-effective development is clear.
·
Other
far and wide problems such as gender development, poverty alleviation, climatic
change, globalisation and liberalisation
of trade, etc. related water supply should be put forward for public
discussions further and later.
Le Anh Tuan
March, 2003
MAJOR REFERENCES
1.
Josefin Abrahamsson, Veronica Svensson (2000). Rural Drinking Water - Quality and Supply in
the
2.
Le Anh Tuan (1995). Environment Impact Assessment on the Mekong
Delta Irrigation projects.
3.
NEDECO, Government
of Vietnam, World Bank,
4.
SIDA (1999) Management and Use of Water Resources (in
English)
5.
SR Vietnam, VN
Water & Sewerage Association, World Bank, (2002). Performance Benchmarking Urban Water Supply
(in English, pdf. file)
6.
State of the Environment
(Website: http://www.rrcap.unep.org/reports/soe/vietnam/issuses/
... )
7.
8.
9.
TABLE APPENDIX
Table
1: Roughly comparison the average monthly rainfall (mm) of some MD provinces
|
Month Stations |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
S |
|
Can Tho Soc Trang Ca Mau Rach Gia Tan Chau Chau Doc Long Xuyen Phu Quoc |
17 9 18 11 9 16 12 28 |
3 2 9 7 15 2 2 24 |
12 14 32 36 55 44 13 55 |
45 64 97 99 103 108 97 138 |
166 224 290 220 166 169 211 306 |
182 247 306 250 154 136 162 396 |
226 248 330 304 162 150 194 438 |
214 264 343 310 112 147 197 543 |
278 266 337 294 180 153 235 522 |
250 289 332 270 286 250 287 328 |
169 171 170 160 172 137 144 179 |
52 40 88 44 64 60 57 78 |
1604 1840 2360 2015 1478 1385 1611 3038 |
Table 2: Calculated groundwater reserve of the
|
Aquifers |
Area (km2) |
Flow rate (l/s.m) |
Deep (m) |
Reserve ( x 1,000 m3/day) |
|||
|
Dynamic |
Natural |
Static |
Elastic |
||||
|
Plitoxen Mioxen |
19,500 23,500 21,500 28,300 |
0.1 - 1.1 0.9 - 1.5 0.1- 1.5 0.2 - 0.9 |
80 60 120 100 |
32 30 27 7 |
972.5 - - - |
17,160 14,100 25,800 25,650 |
478 1,763 2,688 3,420 |
|
Sum = |
97 |
972.5 |
82,710 |
8,349 |
|||
|
·
Sum
of Ground water reserve = 92,128,000 m3/day ·
Ground
water safe yield = 1,069,000 m3/day |
|||||||
Source: Hydrogeological
Division No.8 and NEDECO
(1991)
Table 3:
|
Water users |
Consumption rate (m3 used/month) |
Old charges (VN Dongs) |
New charges (VN Dongs) |
|
Households |
Up to 4 From 4 to 6 From 6 to 10 Over 10 |
1,300 1,300 1,500 1,500 |