THE SELF PURIFICATION CAPABILITY OF MALAYSIAN RIVERS AND SEWAGE LOADING: PURIFY OR POLLUTE

STUDY AREAS: UPPER SUNGAI LANGAT, SUNGAI LANGAT ESTUARY, SUNGAI SKUDAI ESTUARY

PROJECT LEADER: DR. NOOR BAHARIM HASHIM

PROJECT MEMBERS: ASSOC. PROF. DR. RAZALI ISMAIL, KAMARUL AZLAN MOHD NASIR, RUHAIDAH CHE HASSAN, CHUA LEE HWA and MAZNAH ISMAIL.

INTRODUCTION

In Malaysia, only 2 standards are applicable to effluent standards throughout the country: Standard A for discharges upstream of water intake point, and Standard B for discharges downstream of water intake point. These standards are applicable across any inland waterways regardless of its self purification capacity or dilution capacity.

In many developed countries, effluent standards are developed for each individual river system based on the river's own self purification and dilution capacity. Therefore, the level of sewerage loading onto the river system will be determined by the river's capacity to purify level of pollution discharged into it. Thus, a river with high self purification capacity will allow for higher level of sewage loading onto the river system.

A study on the self purification capacity of rivers in Malaysia will enable formulation of level of sewage and other pollution loading onto the river system.


METHODOLOGY

The study shall investigate various river systems in Malaysia and systematically monitor the pollutant levels and its self purifying capacity. The dilution capacity of the river systems shall indicate its self purifying capability. The overall environmental impacts of discharging effluent onto the river system shall also be considered. The economic and social considerations or varying the effluent standards of each waterway must also be taken into considerations.


BENEFITS

Identifcation of sewage loading level for each river systems in Malaysia will enable more cost effective sewage treatment plants to be built. For very sensitive waterways, very high effluent standards can be set to limit pollution levels and allow the river to be self purified. However, for river systems those have high self purifying capacity, higher pollution levels and lower discharge standards may be allowed subjected to the river's self purifying capacity. These allow for savings in capital expenditures at these locations and spending them instead in areas where they are needed, i.e. where the river systems have low self purifying capacity. Therefore, better prioritization of capital expenditures, which lead to better overall river water quality.