OHSAS 18001:2007


Effluent is the waste water generated from residential, commercial, industry & mining activities containing physical, chemical and biological contaminants.

The objective is to generate environmentally safe treated effluent for safe disposal or re-use.

Generally the treatment method is (a) unit operation for removal of large particles, grit & suspended particles (b) Unit processes by chemical or biological treatment for removal of contaminates in the effluent.

Advanced treatment is given for further removal of suspended particles and disinfection for re-use of treated water.


Sewage Treatment is the Process of removing contaminants from Waste Water and House Hold Sewage. It includes physical, chemical and biological processes to remove physical, chemical and biological contaminants. Its objective is to produce an environmentally safe treated effluent and treated sludge suitable for disposal or reuse.

Sewage treatment generally involves three stages called primary, secondary and tertiary treatment.

• Primary Treatment consists of removal of floating materials, oil & grease and suspended particles.

• Secondary Treatment removes dissolved and suspended biological matter.

• Tertiary treatment is to improve the quality of effluent by filtration and