Curb pollution of river -dealing with dry weather flow interception

Abstract

The Mithi River having length of 17.8 km runs through densely populated residential and industrial areas in Mumbai. Except during the monsoon, behaves as a non-perennial water body and carries only sewage during the rest of the year. The Mithi River has a catchment area of 7,295 ha and receives overflows from Vihar and Powai lakes at its origin of 246 m above mean sea level on the periphery of Sanjay Gandhi National Park. The Mithi River flows through densely populated residential and industrial areas, Marol, Andheri, Bail Bazar to meet the Arabian Sea at Mahim Bay. This has resulted into pollution of river water by joining of nallas with Dry Weather Flows. The methodology & flow of study work adopted i.e. data collection, Topographical surveys, measurement of DWF at ingress locations in the river and suggested the feasible solution i.e. Dry Weather Flow Interceptors, STP etc. Under this Study, Identified the 52 nos of DWF (Dry weather flow) outfalls into Mithi River for Area 1 of Mithi River (Filterpada to WSP site). It found that daily 24 MLD DWF is entered into the Mithi river form Filter Pada to WSP Site. This is damaging to the environment, public health and visual landscape of the river & polluted river. So it is necessary to stop ingress of DWF into river & give the suitable treatment before further flow into river. Under this studied in various measures in detail to Curb Pollution of Mithi River. Adequate Dry Weather Flow Interceptors (DWFI), Sewer Network, Sewage Treatment Plant are designed and proposed to treat the Dry Weather Flow for required standards.After implementation of these solutions good results will be achieved i.e. river will flow with treated water all time and get the river to its original natural conditions free from pollution.