1. Proportioning of waste means discharge of Industrial waste(IW) in proportion to the flow of Municipal sewage in the sewer or stream flow in the releasing river.
   1. The objective of proportioning in sewer is to keep constant percentage of Industrial waste to the domestic sewage flow entering the sewage plant.
   2. Proportioning is mostly used in combination with equalisation.

The Purpose of Proportioning:

1. To protect Municipal sewage treatment using chemical from being impared by sudden overdose of chemical contained in the IW.
2. To protect biological treatment devices from shock load of IW.
3. To minimize the fluctuation of sanitary standards in the treated effluents.

It can be activated by:

1. Manually proportioning.
2. Automatically proportioning.

Hydraulic structure used to proportionate waste :- Weirs, Humes etc.