Sanitary Sewage Flow Estimation

SANITARY SEWAGE FLOW ESTIMATION

Sanitary Sewage is the spent water of a community that drains into sewers.

Sanitary Sewage = Domestic Sewage + Industrial Sewage

Theoretically speaking, the quantity of sewage (i.e., domestic sewage + industrial sewage) that is likely to enter the municipal main sewers should be equal to the quantity of water supplied to the contributing area.

i.e., Quantity of Sewage = Quantity of water supplied.

But certain additions and subtractions do take place

(i) Additions due to unaccounted private water supply. Janissonship institue vand bluorta bassidub

(ii) Addition due to ground water infiltration.

(iii) Subtractions due to water losses (leakage, seepage in ground).

(iv) Subtractions due to water lost in evaporation.

Net Quantity of sewage produced-Quantity of water supplied + (i) + (ii)–(iii)–(iv)

Net Quantity of sewage produced-Quantity of water supplied + (i) + (ii)–(iii)–(iv)

*  Usually 80% of water supply may be expected to reach the sewers.

Quantity of Sewage = Per capita sewage contributed per day x Population.

Factors affecting Dry Weather Flow (DWF):

Dry Weather Flow (DWF) is the flow of sanitary sewage alone in the absence of storm

water (during dry season).

(i) Rate of water supply.

(ii) Population growth.

(iii) Type of area served (Residential/Commercial/Industrial).

(iv) Infiltration of sub soil water (leaky joint in sewers and high water table level).