Tuesday, 24 May 2011

WATER POLLUTION IN MALAYSIA

River, Marine & Ground Water
The sources of water pollution in Malaysia have been identified as sewage treatment plants, manufacturing, agro-based industries, animal farms , agricultural activities and surface runoffs.

Quality of river water, 1992-1998
Category
1992
1993
1994
1995
1996
1997
1998
No.
%
No.
%
No.
%
No.
%
No.
%
No.
%
No.
%
Very polluted
7
8.1
11
9.5
14
12.1
14
12.2
13
11.2
25
21.4
16
13
Slightly polluted
55
63.2
73
62.9
64
55.2
53
46.1
61
52.6
68
58.1
71
59
Clean
25
28.7
32
27.6
38
32.7
48
41.7
42
36.2
24
20.5
33
28
Total
87
100
116
100
116
100
115
100
116
100
117
100
120
100

Rivers are easy conduits for disposal of domestic, commercial, industrial and agricultural effluents. Agriculture expansion and industrialisation have overstressed river systems. Many river basins have reached their limits of water supply and are now susceptible to water stress and droughts. Rapid development has produced great amounts of human wastes, wastes from man's activities, including agriculture, industrial, commercial and transportation wastes. A large number of rivers are polluted, some to the extent of being not rehabilitable.

 
Deforestation has also led to the opening up of large tracts of land within river basins and this has resulted in not only increased sediment loading in the river systems but also in the aggravation of floods which further pollute the waters.

          The major pollutants are Biochemical Oxygen Demand (BOD), Ammoniacal Nitrogen (NH3-N) and Suspended Solids (SS). High BOD is contributed largely by untreated or partially treated sewage and discharges from agro-based and manufacturing industries. The main sources of NH3-N are domestic sewage and livestock farming, whilst the sources for SS are mostly earthworks and land clearing activities.

Analysis of heavy metals in 5,613 water samples revealed that almost all samples complied with Class III, National Water Quality Standards for arsenic (As), mercury (Hg), cadmium (Cd), chromium (Cr), lead (Pb) and zinc (Zn), except iron (Fe) with 83 percent compliance.

State
No. of STP
Total PE
Flow
(m3/day)
BOD Load (kg/day)
Selangor
2,563
5,908,450
1,329,401
332,350.31
Perak
1,343
1,300,430
292,597
73,149.19
Johor
1010
1,198,417
269,644
67,410.96
Negeri Sembilan
928
931,458
209,578
52,394.51
Kedah
755
556,637
125,243
31,310.83
Melaka
725
570,192
128,293
32,073.30
Pulau Pinang
650
2,149,001
483,525
120,881.31
Pahang
486
314,830
70,837
17,709.19
WP Kuala Lumpur
299
2,571,877
578,672
144,668.08
Terengganu
224
75,184
16,916
4,229.10
Perlis
36
16,156
3,635
908.78
WP Labuan
32
39,265
8,835
2,208.66
WP Putrajaya
9
72,833
16,387
4,096.86
Total
9,060
15,704,730
3,533,563
883,391.08
Source: IWK Sdn. Bhd.

Note : STP = Sewage Treatment Plant, PE = Population Equivalent

        The main contaminants of the marine waters of all States are suspended solids (75%), Escherichia coli (55%) and oil and grease (35%). Sources of the total suspended solids are agricultural activities, tourism development, coastal reclamation, logging and road construction. Sources of the E. coli are untreated or partially treated domestic and animal wastes. Sources of oil and grease are discharges from vessels such as tank clearing, deballasting, bilges and bunkering, and leakages and disposal of engine oil from ferries and boats. 




         Water samples from wells are analysed for volatile organic compounds (VOCs), pesticides, heavy metals, anions, bacteria (coliform), phenolic compounds, radioactivity (Gross Alpha and Beta), total hardness, total dissolved solids (TDS), pH, temperature, conductivity and dissolved oxygen (DO).


Water samples are taken from wells, rural areas, landfills, municipal water supply, golf courses, agricultural and industrial areas as well as radioactive sites. They are analysed for volatile organic compounds (VOCs), pesticides, heavy metals, anions, bacteria (coliform), phenolic compounds, radioactivity (Gross Alpha and Beta), total hardness, total dissolved solids (TDS), pH, temperature, conductivity and dissolved oxygen (DO). The sampling results show high levels of iron (Fe), manganese (Mn), nitrate, and arsenic.



The authorities, water NGOs and the public are working towards river restoration and rehabilitation. The Drainage and Irrigation Department has initiated a program to clean up rivers of solid waste and silt, to improve water quality to Class III (recreational purposes without body contact) and to beautify strategic stretches of the river for recreational purposes. Intensified enforcement efforts and good environmental management practices contribute to the water quality improvement.

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