JENNIFER GUSTAVSON PHOTO | From left, Group for the East End president Robert DeLuca, The Nature Conservancy conservation manager Kevin McDonald, Long Island Pine Barrens executive director Richard Amper, Peconic Baykeeper Kevin McCallister and Citizens Campaign for the Environment executive director Adrienne Esposito. The group of environmentalists announced their slate of recommendations for Suffolk County's new water quality plan Monday in Yaphank.

Long Islanders will face “serious problems” with their drinking water come 2050 if action isn’t taken now to remedy a groundwater contamination dilemma that has significantly increased within an 18-year time period, environmentalists warned Monday.

Representatives from the Long Island Pine Barrens Society, Citizens Campaign for the Environment, Peconic Baykeeper and the Nature Conservancy met at Camp Olympia near the Carmans River in Yaphank to announce a  slate of recommendations for the county to consider as it finalizes the recently completed Suffolk County Comprehensive Water Resources Management Plan.

The county’s new study, which compares 2005 data to its former 1987 plan, found that nitrogen contamination in the upper glacial aquifer, the area closest to the land’s surface, as well as in the Magothy Aquifer located below the upper glacial aquifer, has increased by more than one milligram per liter.

But Long Island Pine Barrens Society executive director Richard Amper said the study fails to “accurately reflect the magnitude” of those statics, because a one milligram per liter increase in nitrates correlates to a 40 percent increase of nitrates in the upper glacial aquifer and a 200 percent increase of nitrates in the largely pristine Magothy Aquifer.

“We are not saying that people should not drink their tap water,” Mr. Amper said. “But every Long Islander should be concerned about this trend.”

In addition to a decrease in drinking water quality, the study also shows that surface waters — such as rivers, lakes and bays — are also deteriorating.

Peconic Baykeeper Kevin McAllister said that since 90 percent of streams are fed by groundwater, he recommends the county implement stronger standards to limit nitrogen loading.

“It’s a sad day for Long Islanders when these waters become sour,” Mr. McAllister said, noting that Great South, Moriches, Quantuck and Shinnecock bays were added last year to the New York State Department of Environmental Conservation’s “Impaired Waters” list due to excessive nitrogen entering surface waters from sewage treatment plants and septic tanks.

Environmentalists also criticized the county’s study for not including a plan to decrease Volatile Organic Chemicals detected in groundwater.

“These chemicals are known carcinogens and yet they are increasing exponentially in our drinking water supply,” said Citizens Campaign for the Environment executive director Adrienne Esposito. She said most VOCs come from gasoline, pharmaceuticals and cosmetics.

About 80 pesticide-related compounds have also been detected in public, private and monitoring wells throughout the county, the study found.

Robert DeLuca, Group for the East End president and a former biologist for the Suffolk County Health Department, said he believes the county should develop a strategy to engage the agricultural community in creating standards to reduce nitrogen and pesticide contamination.

The group of environmentalists have jointly submitted their recommendations to the county, which is expected to finalize the report later this summer.

A Suffolk County Department of Health spokeswoman did not respond to an email seeking comment for this story.

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