Suffolk OKs 2 new waste treatment options

Developers who want to build small but dense projects in unsewered parts of Suffolk County now have two new wastewater treatment options in their toolbox -- a change officials and environmental advocates hope will help limit rising levels of sewage-related nitrogen in the underground aquifers that supply Long Island's drinking water.

For years builders who wanted to put up small hotels, nursing homes and apartment complexes in areas not served by central sewers had just one option to treat sewage. Some of the 32 projects that used the technology -- an underground fiberglass tank system known as Cromaglass -- racked up hundreds of water quality violations for excess nitrogen, according to state and county records.

Suffolk officials and Cromaglass representatives blamed those problems on poor maintenance and operation and said a recent crackdown has addressed most of the violations. Still, the problem took more than a decade to fix.

Tuesday, after years of prodding by developers and advocates, county health officials approved two additional technologies for use at developments that generate up to 15,000 gallons of effluent per day. Both new systems remove nitrogen from sewage so that it contains no more than 10 milligrams per liter, the state drinking water standard.

"It's definitely a step in the right direction," said Kevin McAllister of the water quality group Peconic Baykeeper, who has long urged Suffolk officials to pursue more advanced wastewater treatment options.

Nitrogen from sewage and septic waste is a problem because it can contaminate wells and foul coastal waters, triggering fish kills and harmful algae blooms. Over the past decade, nitrogen contamination has increased in Suffolk groundwater, according to a draft version of the county's drinking water management plan.

County officials said the new wastewater systems would limit such pollution while giving builders more options to develop commercial and multifamily projects in the three-quarters of Suffolk County not served by central sewers.

One of the new systems -- the Nitrex -- has "exceptional" results and removes nitrogen down to two or three milligrams per liter, officials said. The other is an above-ground plant called the BESST system that has been used here successfully on a larger scale.

"Our goal is to find the most cost-effective approach that will minimize the adverse impacts of nitrogen from wastewater disposal systems on coastal waters," Suffolk health Commissioner Dr. James Tomarken said in a statement.

The new options come after McAllister and others complained about nitrogen pollution from many of the Cromaglass plants -- the very problem they were intended to fix.

Suffolk health officials point out that the Cromaglass violations are relatively small potatoes compared with the vast pollutant load from homes in neighborhoods without sewers. Wastewater from cesspools contains about 50 milligrams per liter of nitrogen -- five times the state limit that Cromaglass plants must meet.

And the plants process only a fraction of the overall volume of wastewater that ends up in the aquifers: less than 310,000 gallons a day, or 0.52 percent of the total flow to Suffolk treatment plants.

But even small plants can contaminate drinking water wells and harm streams and bays, said Martin Trent, former chief of the Suffolk health department's ecology office. "As more and more of these things go in, you don't want to have 30 or 40 of these out there that don't operate," said Trent, who retired in 2010.