Westerly - State of Rhode Island: Division of Planning

The Westerly Comprehensive PlanChapman Pond is included in the RIDEM 2006 List of Impaired Waters due to lead concentrationsand noxious aquatic plants. The source of nutrients and other pollutants can generally be traced tothe surrounding land uses, including an adjacent road salt storage facility and the inactive municipallandfill.Water Quality of Rivers and StreamsThe rivers and streams in the Pawcatuck watershed are now in generally good condition, but thereare threats actively eroding the environmental quality of the watershed. Recent monitoring on thePawcatuck River and its tributaries suggests that the river is threatened by lead levels, which mayoccasionally exceed the national EPA chronic aquatic life standards. Elevated nutrients, particularlynitrate levels, have also been measured in the Pawcatuck River. Fecal coliform bacteria is anotherimportant nonpoint source contaminant, originating from farm and wild animals and failing septicsystems. Several measurements are routinely taken in the watershed to assess the health of aquaticcommunities. Results of the assessment tests indicate that several rivers and streams within thewatershed are stressed, including portions of the Pawcatuck River. 21Water Quality of Coastal Waters and Salt PondsIn the salt pond region, failing or sub-standard septic systems have been identified as the single mostimportant nonpoint source of bacterial and nutrient contamination to the coastal waters. 22 The tidalportions of the Pawcatuck River and Little Narragansett Bay are listed as impaired water bodies inboth Rhode Island and Connecticut as a result of elevated bacteria levels. Currently, the directharvesting of shell fish is prohibited at all times in Little Narragansett Bay due to pollutionclosures. 23 Shell fishing is not permitted in the tidal portions of the Pawcatuck River, from the MainStreet highway bridge in Westerly south to the mouth of the Pawcatuck at Pawcatuck and RhodesPoint. This reach is assessed as partially supporting aquatic life.Oxygen levels are very low because of nutrient over-enrichment. Metals and pathogens are alsothreats in the upper tidal reach. The Westerly wastewater treatment facility is considered to be arelatively minor loading source in comparison to the nonpoint source inputs (urban runoff, stormsewers, etc.) along this stretch of shoreline. 24The salt ponds are considered valuable parts of the coastal wetlands. Of the three major coastal saltponds within the town of Westerly, Quonochontaug Pond (733 acres) is the largest salt pond; itseastern half is within Charlestown and the western end is at Weekapaug Point in Westerly. It isparticularly sensitive to threats of nonpoint source pollution due to prevalent soil types that result inslow permeability and high runoff rates. Water quality in the eastern section is generally good. Inthe western end, restricted tidal flow can result in depleted oxygen levels and, in some restrictedcoves, higher bacteria levels. 25 Bacterial water quality surveys of the pond from 1977 to presentindicate somewhat higher coliform counts adjacent to developed areas, although overall bacterialwater quality remains good. 26 Although there is limited data, it appears that the total averagenitrogen concentration is increasing with time. 2721 …Ibid. p. 522 …BETA Group, Inc., January 2005 (Revised May 2007), Town of Westerly On-Site Wastewater Management Plan, pp. 1-623 …Rhode Island Department of Environmental Management, May 2007, Quality Assurance Project Plan: Little Narragansett Bay and PawcatuckRiver Bacteria Sampling Plan, p. 924 …Pawcatuck Watershed Partnership, 1998, The Pawcatuck Watershed Report, p. 625 …www.saltpondscoalition.org/quonny%20pond.html, Pond Profiles: Quonochontaug Pond.26 …BETA Group, Inc., January 2005 (Revised May 2007), Town of Westerly On-Site Wastewater Management Plan, p. 627 …Callender, Ted. October 2006, Water Quality and Nutrient Status of Quonochontaug Pond – May to October 2006, p. 1Westerly, Rhode Island 45