Aging sewage treatment plants, antiquated septic systems, storm runoff and fertilizer use are loading Long Island's waters with nitrogen, a pollutant that can threaten public health and the environment.
Nitrogen levels have been rising in Long Island's aquifers for three decades, said Stony Brook University marine scientist Christopher Gobler, citing a Suffolk County study. Nitrogen in the aquifer that supplies most of Long Island's drinking water increased by as much as 200 percent between 1987 and 2005, the study of the most recent data available found.
The amounts remain well below the U.S. Environmental Protection Agency limit for safety. But environmentalists and elected officials worry about the continued increase and its effect on the Island's groundwater and surface water.
Millions of pounds of nitrogen are generated on Long Island each year "and unfortunately most of that, as we all know, is not going to sewage treatment plants, but is going to septic tanks" and eventually seeping into groundwater and surface water, Gobler said. "We do expect these numbers to rise."
Nitrogen forms when microorganisms break down in sewage, manures, decaying plants or fertilizers.
The element occurs naturally and is necessary for human health and plant growth. But when ingested in high levels, it can deprive bodies of oxygen in blood. In infants, excess nitrogen in water used for formula preparation can lead to "blue baby syndrome," where the lack of oxygen turns the skin blue. In adults, high nitrogen levels, in severe cases, can lead to brain damage.
Nitrogen pollution is one of the most widespread and challenging environmental problems in the country, according to the EPA. It affects 15,000 waterways, including 2.5 million acres of lakes and reservoirs, and 80,000 miles of rivers and streams, agency officials said.
"Addressing nutrient pollution is a top priority for EPA," said the agency's acting Assistant Administrator Nancy Stoner in Washington, D.C. The contamination "threatens waters used for drinking, fishing, swimming and other recreational purposes," she said.
Septic systems can leak
In Suffolk, 70 percent of the homes and businesses use septic systems, and in Nassau 30 percent are on such systems. The remainder in both counties are attached to public sewers. Both systems, if not maintained or updated, can leak pollutants, experts and environmental advocates said.
"When you flush it down your toilet or put it in your sink, it goes into the groundwater and then into our bays," said Adrienne Esposito, executive director of the Citizens Campaign for the Environment.
But Walter Dawydiak, acting director of environmental quality for the Suffolk County Department of Health Services, said nitrogen levels in Long Island's aquifers are still at 3 to 4.5 parts per million. That's well below the maximum 10 parts per million allowed under public health standards.
Nitrogen levels in the Upper Glacial Aquifer, which supplies much of Long Island's water, grew to 3.38 parts per million in 2005 from 2.45 parts per million in 1985, according to the Suffolk study. The deeper Magothy Aquifer showed an increase in the same period to 1.6 parts per million from 0.96 parts per million.
Fertilizer- or pesticide-laden runoff from lawns and farms also contribute to nitrogen pollution.
To combat the threats, environmentalists and governments have started efforts to increase public awareness about Long Island's water, pass legislation to curb nitrogen levels and boost campaigns to build new sewage treatment plants.
The newly formed Long Island Clean Water Partnership, which includes the Citizens Campaign, Group for the East End, Long Island Pine Barrens Society and The Nature Conservancy, this month launched a $3 million, three-year advertising and education campaign about protecting Long Island's waters.
Lawmaker seeks cleanup
Assemb. Robert Sweeney (D-Lindenhurst), chairman of the Assembly Committee on Environmental Conservation, has sponsored several pieces of legislation intended to clean up Long Island's waters, including one to establish state groundwater standards limiting nitrogen levels to 2 parts per million.
"We have one source of drinking water and it's beneath our feet," Sweeney said. "And there is no Plan B if something goes wrong with that."
Suffolk Legis. Kara Hahn (D-Setauket) said expanding the sewer system would considerably help combat the increasing nitrogen. But at a cost of $2.1 billion to hook up a mere 40,000 homes, that approach is too expensive, despite the urgency, she said.
A variety of small sewage treatment plants have recently been proposed or undertaken in Suffolk.
County officials this month broke ground on a $75 million sewer expansion in Hauppauge Industrial Park that consists of $41 million to upgrade the treatment plant and $34 million for sewer installation and pump stations. Northport Village was selected to receive a $3.1 million state grant and as much as $3.03 million in loans to upgrade its sewer plant.
In Nassau, the Bay Park Sewage Treatment plant processes wastewater for about 40 percent of the county's population and has long been blamed for nitrogen loading in the Western Bays. The county samples nitrogen levels monthly.
The plant in July started a pilot program using bacteria to remove nutrients such as nitrogen. Early indications show that 80 percent of the nitrogen is being removed from treated water, which is discharged into Reynolds Channel, officials said.
"With those kinds of numbers, it illustrates how far we can go with this type of technology at Bay Park," County Executive Edward Mangano said Tuesday. "The results are very encouraging."
If expanded to the entire facility, the amount of nitrogen removed would likely decrease but still have a dramatic impact, officials said.
The test will run for five months and the data will be used to help design and build a full-scale facility at Bay Park, Mangano said. He is seeking $722 million in borrowing for critical sewer system repairs, particularly for the electrical system at Bay Park.
Superstorm Sandy flooded that plant and Long Beach's sewage treatment plant, and sent more than 2 billion gallons of raw or partly treated sewage into channels and bays.
The EPA and state Department of Environmental Conservation have declared swaths of water on the South Shore and Long Island Sound "impaired," citing elevated levels of infectious microorganisms, reduced oxygen and increased nitrogen loading.
Algae can be a problem
Excess nitrogen in surface water allows algae that feed on the element to grow unchecked, depleting the waters of oxygen and killing off marine life.
That worries environmentalists and elected officials because polluted waters mean less fishing and recreational boating, closed beaches and fewer tourism-generated dollars in a region with an economy dependent on those industries.
"Our tourism, our quality of life, our economy is so reliant on the quality of those waterways and I think that while we face an extraordinarily difficult fiscal reality, the people of Suffolk County do not want us to continue to allow the degradation at the pace it has occurred," Hahn said.
Southampton Supervisor Anna Throne-Holst, an Independence Party member, is leading an effort to tap state funds to create a collaboration among area research institutions to find the best water quality control approaches for Long Island.
Riverhead Town Supervisor Sean Walter, a Republican, supports the collaborative approach. "It's time for us to really put thinking caps on in looking to improve these systems," he said.
Throne-Holst in July submitted a proposal to the Long Island Regional Economic Development Council seeking a $2.7-million state grant to establish an incubator facility for Stony Brook University, Brookhaven National Laboratory, Cornell Cooperative Extension and the Suffolk health department to find the best system to reduce nitrogen content in septic systems.
The project, she said, has the backing of all of Suffolk's town supervisors and represents the start of what she said she hopes becomes a sustained effort to save the waters.
"It puts the money behind funding the research and development and the actual manufacturing of technology," she said. "We realize we have to come at it from many different directions."
With Emily C. Dooley
CORRECTION: An earlier version of this story misstated the amount of raw or partially treated sewage released by the Bay Park treatment plant after superstorm Sandy.