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.