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Improving wastewater treatment and reducing other point-source polluters has decreased phosphorous and nitrogen levels in the Inland Bays. Still, for more than 15 years, monitors have seen no decrease in nutrient pollutants in the bays. Of the three Inland Bays, only Rehoboth Bay is meeting recommended allowable levels of pollution.
The members of the Citizens Advisory Committee (CAC) to the Center for the Inland Bays (CIB) heard an update on water quality as part of their meeting Tuesday, Jan. 8.
The Department of Natural Resources and Environmental Control (DNREC) collects samples from the Inland Bays four times a year, measures the concentration of pollutants and then issues data in five-year sets. Rehoboth Bay meets the state’s standards for both phosphorous and nitrogen, known as total maximum daily loads (TMDLS).
Only one site in the Indian River Bay, the one closest to the inlet where the tides flush water through regularly, meets its TMDL, and no part of Little Assawoman Bay meets TMDL requirements.
Chris Bason, science and technical coordinator for the CIB, emphasized that water quality is only one aspect of the overall health of the bays. Clarity and algal growth are also key.
“There is good news for Rehoboth Bay, but some pretty bad news for parts of Indian River Bay and for Little Assawoman Bay,” said Bason.
DNREC uses the median numbers of its data, which means that half the time the nutrient concentrations are higher than the numbers used to compare to TMDL, which can have a serious impact on ecosystems.
Regulations on wastewater treatment plants have helped slash phosphorous levels in the bays. Much more work can be done to reduce the amount of nitrogen, said Bason.
CIB’s pollution control strategy outlines ways to reduce nitrogen, including improving treatment plants and stormwater controls, restoring wetlands, reducing air emissions and impervious surfaces, improving septic systems and implementing a buffer regulation.
Buffers are extremely important in reducing nitrogen, Bason said, because the plants absorb nitrogen from water and soil and keep runoff from reaching waterways.
Forested buffers along waterways control flooding, filter water, and have recreational and aesthetic values. CIB calls for buffers to be included as part of a comprehensive wetlands management strategy.
Wetlands assessment
Amy Jacobs of DNREC’s Watershed Assessment Section said the vast majority of wetlands have at least one stressor present.
Even though so many acres of wetlands are impaired in some way, they can be managed so that they can still perform their important functions, said Jacobs.
So far, the team, assisted by staff from CIB, has observed and graded nontidal wetlands. This year, the area’s tidal wetlands will be surveyed.
Seal Island
Seal Island, a former wetland area and bird habitat near Fenwick Island, has been reduced to a bare mud flat. Along with DNREC and the U.S. Army Corps of Engineers, CIB has a project under way to restore five of the seven acres that remain of Seal Island.
Eric Buehl, habitat coordinator for CIB, is working with the state and the Corps of Engineers as well as with Fenwick Island and some of its residents to restore the eroding island. The plan includes the use of fiber logs to stabilize the western shoreline, a variety of native grasses, and a network of twine and mylar flags to keep snow geese away from the grasses until they are established, said Buehl.
He said the center still has to wait for some federal and state permits but hopes to begin planting grass on Seal Island in spring 2009.
Contact Leah Hoenen at leah@capegazette.com
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