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State of Waste Management in South East Asia

E. Industrial Wastewater

The sources of industrial wastewater are mostly agro-based industries, including animal farms, and the manufacturing industries. In many of the ASEAN countries, this industrial wastewater may include domestic sewage.

Malaysia has identified 16 types of manufacturing processes that contribute to industrial wastewater discharge. The main polluting sources are the food and beverage industry (23.7 percent), followed by electric and electronic industry (11.4 percent), chemical based industry (11.2 percent), paper (8.8 percent), textile (7.4 percent), metal finishing & electroplating (5.3 percent), crude palm oil mills (5.3 percent) and raw natural rubber factories (2 percent) (Ref. Malaysian Department of Environment Environmental Quality Report, 2000).

In the absence of available specific data, it is fair to assume that there would be different sources of wastewater in the other ASEAN countries based on the types of industries present there. Unfortunately there are no databases provided in most of the developing nations for identifying the main industrial wastewater sources and quantities generated. Some countries include leachates from landfills as industrial wastewater.

Discharges from industries are extremely variable in quantity and characteristics, and have been largely contributed to substantial deterioration of water quality in the rivers, lakes and other receiving water bodies, since there has been little or no treatment of the wastewater at all. This situation is affecting the availability of clean water supply whether from surface water or ground water.

F. Storm Water

Storm water quantities are generally estimated from the precipitation-evaporation rates of each country. ASEAN countries lie in the tropics and generally experience high rainfall compared with other regions in the world. However, there can be wide variations depending on location. Mandalay in Burma experiences rainfall of from 661mm to 1024 mm annually. Kuala Lumpur, Malaysia, has an average annual rainfall of about 2500 mm.

Singapore has an estimated storm water runoff of 770 million cubic meters annually (1990-2000 data). Malaysia has a total estimated average runoff of 566,000 million m3 annually (1997). From the precipitation-evaporation data of each country it will be possible to estimate the respective quantities of storm water runoffs.

Storm water could be collected from house roofs, paved areas and roads, and could carry solids depending on how much debris and pollutants lie in the path of the runoff. Storm water drainage in most urban areas would generally consist of roadside drains leading ultimately to natural streams, rivers and other bodies of water.

In most cases the pollutant load of storm water would be lower than that of other types of wastewater. However, water in the drainage system may inevitably be contaminated with fecal matter from latrines and coliform septic tank effluent, presenting direct health risks. Poor drainage may result in flooding as well as cause stagnant pools of water - both further contributing to health risks.

In Malaysia some of the problems encountered due to storm water runoffs include:

  • Construction cavities and mud flows
  • Flash flood
  • Water pollution and ecological damage
  • Urban slope failures
  • Traffic disruption and accidents
  • Surcharges and overflows from wastewater facilities
  • Garbage and floating litter
  • Sediments

These problems are particularly prevalent in major zones of urbanized and urbanizing centers and new socio-economic growth areas.


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