Effluent Disinfection and Coliform Bacteria in Raritan Bay

Effluents from Water Pollution Control Plants in New York City are disinfected during the swimming season, but a new ruling from the Interstate Sanitation Commission will require year-round disinfection beginning in July 1986. The goal of this policy is to enhance shellfishing in Raritan Bay.The NYC Department of Environmental Protection performed mathematical modelling studies and extensive field analyses which show that NYC WPCP\´s do not significantly affect levels of coliform bacteria in Raritan Bay\´s shellfishing areas. The long distance from NYC to the shellfish beds, complex current patterns, and a persistent background level of coliform bacteria are suggested as being responsible for this finding that NYC effluent disinfection does not enhance the sanitary quality of waters in Raritan shellfishing areas. Similar studies by other agencies reviewed in this paper also support the finding of "no effect".