Environment

How nitrogen finds its way into surface water

He said the study further emphasizes the need for assistance in funding research to help growers with integrating slow-release fertilizer and adopting other best-practice techniques.

“It’s not going to be fixed overnight. We need the funding and the help to address it,” he said. “Farmers are under a microscope.”

He added that, overall, the study confirms that “the main culprit is residential septic and sewage.”

According to the study, researchers used what is known as the Nitrogen Loading Model — which is widely used, in part because of its “ability to quantify sources of nitrogen with relative ease and accuracy, utilizing existing information about atmospheric deposition rates, on-site wastewater systems, sewage treatment plant outputs, fertilizer application rates, and spatial data on population, land use, and land.”

The same model has been used by the Environmental Protection Agency and by researchers on Cape Cod in Massachusetts, an area facing similar water quality issues, Mr. Lloyd said.

According to the study, atmospheric deposit rates were calculated from a Cedar Beach monitoring location in Southold belonging to the National Atmospheric Deposition Program.

It was the only available site within the study area, researchers said.

Mr. Gergela said in the future, he would like to see deposits from wildlife, including deer and Canada geese, accounted for in these studies.

High nitrogen levels in area waters have been feeding harmful algal blooms, which in turn have damaged the local ecosystem by depriving bodies of water of oxygen and negatively affecting area fisheries. Nitrogen levels have likewise been increasing in area drinking water.

“In deploying their nitrogen loading model, the Conservancy has specifically identified the sources of contamination from 43 areas in the Peconic Estuary,” Suffolk County Executive Steve Bellone said last week in release about the study.

“It is this very specific scientific data that will provide a road map for Suffolk County as we set about reclaiming our waters,” he said.

In April, Mr. Bellone joined Congressman Tim Bishop (D-Southampton), county Legislator Al Krupski (D-Cutchogue) and a coalition of East End agricultural and environmental organizations to call on U.S. Department of Agriculture Secretary Tom Vilsack to designate the Peconic Estuary as a critical conservation area under the Regional Conservation Partnership Program.

The designation would help to fund agricultural conservation and habitat restoration efforts within the estuary.

Water quality advocate Kevin McAllister said The Nature Conservancy report helps confirm the leading sources of nitrogen that need to be targeted in the future.

“A key point made here is that in implementing any kind of strategy or plan over time, we may have to address these watersheds individually, which may be the right prescription for improving things,” Mr. McAllister said.

The Nature Conservancy: Nitrogen Load Modeling to the Peconic Estuary by Timesreview