Water pollution is caused by point and non-point sources. Point sources include sewage treatment plants, manufacturing and agro-based industries and animal farms. Non-point sources are defined as diffused sources such as agricultural activities and surface runoffs.
In 2006, the Department of Environment (DOE) registered 18,956 water pollution point sources comprising mainly sewage treatment plants (9,060 : 47.79% inclusive of 601 Network Pump Stations), manufacturing industries (8,543 : 45.07%), animal farms (869 : 4.58%) and agro-based industries (484 : 2.55%)
represents the distribution of industrial water pollution sources from agro-based and manufacturing industries compiled by the DOE in 2006 through field surveys and questionnaires. A total of 9,027 sources were identified with Selangor having the highest number of water pollution sources (1,850 : 20.49%), followed by Johor (1,774 : 19.65%).
According to statistics compiled by the Veterinary Department of Malaysia, the total standing pig population for 2006 was about 1.67 million, a decrease of 1.76 percent compared to 1.7 million in 2005. Correspondingly, the number of pig farms decreased to 869 farms compared to 898 in the previous year.
The number of sewage treatment plants under the management of Indah Water Konsortium Sdn. Bhd. (IWK) had increased to 9,060 in 2006 compared to 8,782 plants in 2005. Selangor had the largest number of sewage treatment plants (2,563 : 28.3%), Perak (1,343 : 14.8%), Johor (1,010 : 11.1%) and Negeri Sembilan (928 : 10.2%) .
BOD POLLUTION LOAD
Domestic sewage discharge, in the form of treated sewage and partially treated sewage, remained the largest contributor of organic pollution load with an estimated biochemical oxygen demand (BOD) load of 883,391.08 kg/day. The estimated BOD loading contributed by other major sectors were agro-based and manufacturing industries (76,790.77 kg/day) and pig farming (213,215.00 kg/day). Table 6.1 indicates the total BOD load in kg/day discharged from sewage treatment plants throughout Malaysia in 2006.
Table 6.1 Malaysia: Total BOD Load (kg/day) from Sewage Treatment Plants
|State||No. of STP||Total PE||Flow (m3/day)||BOD Load (kg/day)|
|WP Kuala Lumpur||299||2,571,877||578,672||144,668.08|
Sumber: IWK Sdn. Bhd.
STP = Sewage Treatment Plant
PE = Population Equivalent