PROVIDENCE - The Department of Environmental Management will hold an informational meeting on Thursday, February 27 to discuss the draft water quality restoration plan for Scott Pond in Lincoln. The meeting will take place from 4:30 p.m. to 6 p.m. at Lincoln Town Hall.
Scott Pond does not meet state water quality standards for total phosphorus and dissolved oxygen. These water quality impairments adversely affect both recreational use of the pond and aquatic life. As a result of elevated phosphorus levels, the pond frequently experiences excessive growth of algae, low dissolved oxygen levels, and cyanobacteria blooms. These nuisance conditions impact aquatic life, and in the case of cyanobacteria blooms, make the pond unsafe for recreation.
Wastewater and storm water discharges represent the two most significant sources of pollution to the pond. The Blackstone River is the only tributary to Scott Pond, and a majority of the river's flow during dry periods consists of treated wastewater discharged from the Woonsocket wastewater treatment facility and four facilities located in Massachusetts. Also, portions of the watershed are heavily urbanized. As a result, storm water runoff containing phosphorus flows largely untreated into Scott Pond during rain and/or snowmelt events, further degrading the pond's water quality.
Other sources of pollutants to Scott Pond may include re-suspension of nutrient-rich sediment in the Blackstone River and Canal, and the internal release of phosphorus from pond sediments. While these sources may intermittently contribute pollutants to pond, they are not easily quantified.
The Department has drafted a water quality restoration plan, known as a Total Maximum Daily Load (TMDL) that details specific pollution abatement requirements and recommendations for pollution sources in Rhode Island including urban runoff, and internal cycling from the release of phosphorus from lake sediments. The Town of Lincoln and the RI Department of Transportation (RIDOT) will be required to amend their Storm water Management Program plans consistent with the requirements described in the document. TMDLs are mandated by the federal Clean Water Act and establish the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards.
Inflow from the Blackstone River via the Blackstone Canal is responsible for the majority of the external phosphorus load to Scott Pond. DEM has determined that lower effluent limits for total phosphorus that DEM issued to the Woonsocket WWTF in 2008 and that EPA recently issued to the four MA facilities are protective of Scott Pond.
The TMDL document is available online at DEM's website: www.dem.ri.gov/programs/benviron/water/quality/rest/reports.htm#draft
DEM is accepting public comments on the TMDL document for inclusion in the public record until March 31st. Written comments can be submitted to Scott Ribas in DEM's Office of Water Resources via email to firstname.lastname@example.org, or mailed to Scott Ribas, DEM Office of Water Resources, 235 Promenade Street, Providence, RI 02908.