IMPACT OF STORM WATER RUNOFF ON EFFICIENCY OF THE EFFLUENT TREATMENT-PLANT - A CASE-STUDY

Monitoring of performance of wastewater treatment systems of an efflue nt treatment plant is a routine process. However, monitoring is not an y easy process when storm water is mixed with wastewater, This is beca use the mixed water runoff varies significantly in physico-chemical pr operties unlike in the case of wastewater alone, The present work eval uates impact of storm water runoff on existing sewage treatment plant situated in an industrial township, Significant dilution effect is obs erved during monsoon period (June-September) in the influent and efflu ent characteristics of sewage, The estimated excess runoff water durin g these months is mainly due to the rainfall in the region and due to absence of proper control or design for collection of storm water, the reby avoiding the discharge of the storm water into the treatment plan t. This has resulted in the reduction of BOD, GOD, total nitrogen and total phosphorus, thus decreasing the efficiency of gas generation.