Beach and Shellfish Closures
Water pollution affects human uses of Narragansett Bay as well as its ecology. Beachgoing and shellfishing are among the most popular recreational activities on the Bay. Yet many areas of the Bay are permanently or periodically closed to swimming and shellfishing due to high levels of bacteria, considered an indicator of disease-causing organisms. Sources of bacteria include discharges of raw sewage from combined sewer overflows (CSOs), failing septic systems, cesspools, and wild and domestic animals.
Rhode Island uses Enterococci, a group of bacteria found in warm-blooded animals, to assess the safety of bathing waters, while a broader group known as fecal coliform is used for shellfishing areas based on U.S. Food and Drug Administration requirements. Once a beach violates state criteria, it remains closed until new samples indicate that conditions have improved. Shellfishing areas are either permanently closed, permanently open, or conditional, meaning they’re closed to shellfishing for a week following heavy rain. In addition, the R.I. Department of Environmental Management (RIDEM) conducts routine shoreline surveys near shellfish growing waters to locate potential bacterial sources.
The R.I. Dept. of Health has conducted federally funded sampling at all 69 licensed saltwater beaches since 1995, while RIDEM runs the state-funded monitoring of all commercial shellfishing areas. Both beach and shellfishing area closures are strongly influenced by summer weather, particularly rainfall, which washes bacteria from the land into nearby stormdrains. Beach closures in the middle and lower reaches of Narragansett Bay also tend to be related to local stormwater runoff, a common factor for beach closures nationally. The upper reaches of the Bay, north of Conimicut Point in Warwick and Nayatt Point in Barrington, are closed to swimming and shellfishing due to high bacterial levels from urban runoff, CSOs and other sources. Newport Harbor has long been closed to shellfishing, and King’s Park Beach was permanently closed to swimming in 2004 due to stormwater contamination from the nearby CSO.
Beaches on Greenwich Bay and Conimicut Point accounted for the largest percentage of closures over the last several years, with beaches in a number of other areas also strongly impacted by stormwater runoff. In some of these areas such as Greenwich Bay, new efforts to connect homes to sewer lines are expected to help improve the situation. In addition, recent efforts have been made to provide stormwater treatment and decrease this source at several beaches where it has been a problem, such as Scarborough Beach and Narragansett Town Beach.
Shellfish closures on Narragansett Bay reflect a north–south pollution gradient as well as the impact of local stormwater runoff. Bacteria levels impair 21 percent of Rhode Island’s estuarine waters for shellfishing, but closure rates in the Upper Bay are projected to decrease due to the CSO retention tunnel recently completed in Providence by the Narragansett Bay Commission. RIDEM completes a yearly re-assessment of the bacterial condition all shellfish waters based upon the previous year’s water sampling and shoreline survey results. Maps of shellfish closures are available on RIDEM’s website at www.dem.ri.gov.
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