Water Quality and Public Health: Pathogen Risks in Storm Waters and Combined Sewage Overflows

Prevention and control of waterborne diseases requires an understanding of the ways environmentally transmissible pathogenic bacteria, viruses and parasites are spread. We now understand that climate factors particularly rainfall play a significant role in waterborne disease and climate change along with our aging wastewater infrastructure contribute to this risk. Drinking water outbreaks have been statistically connected to climate, however the connection to recreational waterborne disease risks has been more difficult to demonstrate. Quantitative microbial risk assessment (QMRA) is now a field which has developed over the last decade and is used to address both probability of infection and community risks. The new challenges facing the development of a strategy for achieving community goals of for water quality and water safety require that greater specificity regarding the infectious agent is addressed and that better assessment of exposure is undertaken. The Great Lakes are a unique coastal environment, used not only as a source of fresh water for municipalities, agriculture and industry but they also support a significant commercial and sport fishing industry. Tourism is important and every year millions of people visit the 500 plus recreational beaches in the Great Lakes. Water quality degradation along the coastline of the Great Lakes associated with fecal pollution originating from combine sewage overflows carries with it potential health risks to those using the water. Viral and parasitic waterborne disease associated with sewage spills have been addressed using a QMRA framework demonstrating risks from 1/10 to less than 1/million.