Providence, RI—Each year, an estimated 3,500 people suffer from illnesses caused by recreational exposure to sewage overflows at U.S. beaches.
This estimate, from a 2004 EPA report, likely captures only a fraction of the total number of illnesses attributable to sewer overflows, because “unrecognized” beaches and recreational activity, such as fishing and boating, were excluded from the study.
Sanitary sewer systems are designed to carry only raw sewage from residences and industry, whereas combined sewer systems are designed to carry stormwater runoff as well.
While the Clean Water Act requires both systems to provide treatment prior to discharge, large volumes of stormwater can overwhelm treatment plants during heavy rainfall, causing untreated wastewater to be diverted to the nearest lake, river, stream or coastal waterway.
NELC has been working with Environment Rhode Island to prompt local and state officials to take concrete steps to eliminate the discharge of untreated sewage into Rhode Island’s Narragansett Bay.
The repercussions of sewer overflows in the bay are severe. Rhode Island has 76 sewer overflow outfalls, and all of them discharge into the Narragansett Bay watershed. The state has listed the bay as an impaired water body due to excessive amounts of pathogens and nutrients.
Waterborne pathogens from sewer overflows can pose a major hazard to public health, causing infections, dysentery, hepatitis A and gastroenteritis.
Children are especially susceptible to pathogenic illnesses from sewer overflows. They tend to swallow the water during recreation, and to ingest large amounts for their size. Teenagers and adolescents also tend to congregate at “unrecognized” beaches, which are often closer to overflow discharge pipes and thus more contaminated.
Subsistence fishers, who consume more seafood than the general population, are also at increased risk. Although consumption advisories have been posted, the bay is dotted with families raking for clams and oysters and consuming their catch.
Further, pathogens and nutrients from combined and sanitary sewer over- flow threaten the survival of fish species by reducing dissolved oxygen levels and killing bacteria essential to aquatic ecosystems of the bay.
Technology to reduce the impact of sewer over- flows is widely available. The city of Providence has nearly completed construction of an underground tunnel that will store excess flow during wet weather and transport the wastewater to a secondary treatment plant during dry weather. Numerous other municipalities in the Narragansett watershed, however, have not seriously addressed the issue.