Malaysia Malaysia’s new regulations to restrict effluent discharge into sewage system

Malaysia’s new regulations to restrict effluent discharge into sewage system

On October 25, 2021, Malaysian government promulgated the Water Services Industry (Prohibited Effluent) Regulations 2021 (hereinafter “the Regulations”). The Regulations stipulate that no person shall discharge or permit discharging any “prohibited effluent” as specified in the Schedule of the Regulations to a public sewage system or public sewage treatment plant without the approval of the National Water Services Commission (SPAN). Applications for approval on discharge of wastewater must be made in a manner to be determined by SPAN. The Regulations will come into force on December 1, 2021.

The original text of the Regulations can be downloaded from:


Prohibited Wastewater

The following (1) to (8) are specified as “prohibited effluent” in the Schedule of the Regulations:

(1) Discharges containing pollutants (e.g., pollutants that require oxygen for their oxidative decomposition) at a flow rate or concentration that is enough to impair a sewage treatment plant, either alone or by interaction with other pollutants, including but not limited to the following parameters and their respective permissible limit values.




Limit value

1 Temperature °C 40
2 pH 6.0–9.0
3 Biological Oxygen Demand (BOD) mg/l 250
4 Suspended Solids (SS) mg/l 300
5 Chemical Oxygen Demand (COD) mg/l 500
6 Total nitrogen mg/l 50
7 Ammoniacal nitrogen mg/l 30
8 Total phosphorus mg/l 10
9 Oil and Grease mg/l 50

(2) Any discharge or substance that passes through the sewage treatment plant and cause a violation of the Environmental Quality (Sewage) Regulations 2009;

(3) Any discharge or substance that affect the discharge of sewage sludge as organic compounds;

(4) Any discharge or substance of objectionable color, including but not limited to dye residues and vegetable tanning effluent, which pass through a sewage treatment plant and enter a watercourse without being effectively treated by sewage treatment processes* and:

(i) do not respond to sewage treatment processes and sewage treatment plant used; or
(ii) respond to sewage treatment processes but still do not satisfy the applicable legal requirements on the disposal or treatment of sewage effluent or sewage sludge disposal;

(5) any discharge or substance that damages, reduces the function of, interferes with or causes a disturbance to a sewage system and its functions or create toxic effects in waterways that are dangerous to humans or animals including but not limited to:

(i) detergents, active surface agents or any substance that may cause excessive foam;
(ii) toxic solids, liquids, gases, vapors or fumes;
(iii) ammonia, ammonium salts or any chelating agent which will produce metallic complexes;
(iv) phenols, hydrogen sulfide or other odor-producing substances;
(v) tankered pollutants;
(vi) heavy metals;
(vii) acidic materials having a pH lower than 6.0 or strong acids or concentrated plating solutions whether neutralized or not;
(viii) scheduled waste as prescribed under the Environmental Quality (Scheduled Waste) Regulations 2005;
(ix) radioactive residues or isotopes; and
(x) pesticides, fungicides, herbicides, insecticides, rodenticide and fumigant;

(6) any grease or oil that is discharged to a sewage system and may clog a sewage pipe or overload a grease treatment equipment, including but not limited to oil discharged from restaurants or any other facility, wax, animal fat, oil, whether emulsified or not, as well as any substance that can solidify or become viscous at temperatures between 0⁰C and 40⁰C;

(7) solid or viscous substance that may obstruct flow in a sewage system, including but not limited to ashes, cinders, sand, mud, straw, metal, glass, rags, feathers, tar, garbage, paunch manure, hair, flesh, organs, paper materials, waste from garbage grinders, pieces of wood, asphalt waste and residues from the refining process of fuel or lubricating oil;

(8) Any discharge or substance that may decrease recyclability or may interfere with the process of reclamation of effluent or any other product of a sewage treatment plant including residues, sludge and scums.


*Sewage treatment process means a series of appropriate processes selected to ensure compliance with effluent standards under normal operation of a sewage treatment plant.

Author / Responsibility

AOKI Kenji

Senior Consultant, EnviX Ltd.
General Director, E&H Consulting Co., Ltd.

Business Performance

Expertise in EHS (environment, health and safety) consulting in ASEAN region.
- Environmental regulations updating
- Chemical regulations consulting


MSc in Earth Science, The University of Tokyo

AOKI Kenji