Massachusetts Agency Seeks Comment on Plans to Clean Up Nantucket, Polpis Harbors
The Massachusetts Department of Environmental Protection (DEP) will
hold a public meeting on Oct. 9 to seek comment on a draft document
identifying the need to limit and reduce the nutrient nitrogen in the
coastal waters of Nantucket and Polpis Harbors on the Island of
Nantucket.
The embayment restoration plan for these estuaries, formulated by
DEP and the University of Massachusetts/Dartmouth School for Marine
Science and Technology (SMAST), is proposed as part of a comprehensive
six-year, collaborative project intended to improve estuarine water
quality in 89 embayments along the southeastern Massachusetts coastline.
Nantucket and Polpis harbors are currently impaired by excess
nutrients, mainly nitrogen. These embayments are listed on the 2004
Massachusetts Integrated List of Waters as impaired by nutrients and
pathogens.
Steady population growth and increased land use development,
particularly during the last several decades in southeastern
Massachusetts, has created an overabundance of nitrogen in the region's
harbors, bays and estuaries. The primary controllable source of
nitrogen is stormwater and wastewater discharged from septic systems.
Leaching lawn fertilizers, discharges from agricultural land uses,
nutrient-rich sediments, and atmospheric deposition also contribute
varying quantities of nitrogen.
At the public meeting, DEP staff will present a draft Total Maximum
Daily Load (TMDL) for limiting nitrogen to the amounts that the water
bodies can absorb without violating water quality standards and
impairing uses such as fishing and recreational activities. The plan
calls for reducing watershed sources of nitrogen by up to 57 percent.
Most of the reductions will be from better treatment and handling of
runoff and wastewater, but nitrogen from fertilizer use should also be
controlled wherever possible.
"This cleanup plan charts a new path for enhancing recreational
opportunities and restoring ecological health on Nantucket," DEP
Commissioner Laurie Burt said. "Nantucket officials have shown great
initiative and commitment by providing the leadership necessary to
improve future water quality on the island."
The major components of this effort included several years of
chemical, physical and biological studies within the Nantucket Harbor
System, and the use of a dynamic water quality model that linked the
watersheds and embayments to determine the present sources of nitrogen
and the loading rates from each, the nitrogen concentrations in each
embayment, the nitrogen concentrations that will result in the
restoration and protection of the embayments, and the target nitrogen
loading rates that will achieve those protective concentrations. This
watershed modeling and TMDL analysis will serve as a planning tool for
communities to implement new comprehensive wastewater management
strategies in order to improve estuarine water quality.