This standard provides criteria for the process design and construction of waste stabilization ponds (WSPs) for treating domestic sewage and biodegradable industrial wastewater. It covers the design of anaerobic, facultative, and maturation ponds, specifying key parameters like organic loading rates, detention times, depths, and temperature correction factors.
Lays down the criteria for the design of waste stabilization ponds for the treatment of domestic sewage and industrial effluents.
Quick Reference Values
Recommended depth of anaerobic pond2.5 to 5.0 m
Recommended depth of facultative pond1.5 to 1.8 m
Recommended depth of maturation pond1.0 to 1.5 m
Typical detention time in anaerobic pond2 to 5 days
Permissible surface BOD loading for facultative ponds (25°C)200 to 300 kg/ha/day
Recommended inner side slope for ponds1V:2.5H to 1V:3H
Minimum freeboard for ponds0.5 m
Key Formulas
A = (Q * Li) / Ls — Area of facultative pond based on surface loading
kt = k20 * (1.05)^(T-20) — Temperature correction for BOD removal rate constant (k)
V = Q * t — Volume of pond based on detention time
t = (log(Ni) - log(Nt)) / kb — Detention time in maturation pond for pathogen removal (simplified)
Practical Notes
The CPHEEO Manual on Sewerage and Sewage Treatment is a more current and widely used reference that supplements or supersedes some recommendations of this code.
Pond performance is highly dependent on ambient temperature, which significantly affects the BOD removal rate constant (k). Designs must consider the lowest expected monthly average temperature.
Proper siting is crucial to avoid nuisance; consider prevailing wind direction, distance from habitation, and land availability as per Clause 3.4.