By GREGORY ZELLER //
A simple sand-and-wood filtering system could replace cesspools on Long Island and across the state.
A white paper issued this week by Stony Brook University’s Center for Clean Water Technology discusses how Nitrogen Removing Biofilters, using locally sourced natural materials, have shown the ability to remove high amounts of nitrogen from household wastewater.
The NRB technology is not proprietary to SBU – tests are already underway in other regions – but it shows great promise for Long Island’s particular set of water-quality issues. Nitrogen has been identified as Island groundwater’s Public Enemy No. 1, making the NRBs, which are also effective against other contaminants, an “economically viable alternative” to traditional onsite wastewater treatment facilities, according to the university, including “high-performance” facilities.
In full-scale pilot studies investigated by the Center for Clean Water Technology, NRB systems incorporating sand and finely ground wood are treating household wastewater “as well or better than the most advanced wastewater-treatment plants,” noted Chris Gobler, CCWT co-director and professor in SBU’s School of Marine and Atmospheric Sciences.
Aside from their effectiveness in removing nitrogen, the NRBs are “also showing highly efficient removal of most pharmaceuticals and other personal care products,” according to Harold Walker, CCWT co-director and chairman of SBU’s Department of Civil Engineering.
Added bonus, according to Walker: The systems are “passive by design,” meaning they are low-maintenance and energy-efficient. The gravity-based NRBs – comprised of a sand-based “nitrification layer” and a sand-and-ground-wood “denitrification layer” – connect to a standard septic tank/pump chamber, with a “low-pressure distribution system” regularly delivering wastewater.
In those pilot studies, the systems have “demonstrated the ability to consistently achieve” high percentages of nitrogen removal (up to 90 percent) and “efficient attenuation” of pathogens, pharmaceuticals and personal-care products, according to the white paper, Nitrogen Removing Biofilters for Onsite Wastewater Treatment on Long Island: Current and Future Prospects.
The treatise calls the results “encouraging.” Other assessments are more flattering.
Richard Amper, executive director of the Long Island Pine Barrens Society, ranked the NRB technology “among the most promising we’ve seen in Long Island’s effort to restore water quality,” while Chris Clapp, an Island-based marine scientist for The Nature Conservancy, suggested a “transformative impact on our regional wastewater management.”
“This novel technology is game-changing for the evolution of how we remove nitrogen pollution from residential wastewater,” Clapp said.
Citing “Long Island’s water-quality crisis,” New York State Assemblyman Fred Thiele Jr. (R-Bridgehampton) credited the CCWT with focusing its research in the right direction, noting the NRB white paper puts the center “at the forefront of developing and utilizing effective and affordable on-site wastewater treatment systems.”
The need for better nitrogen-removal protocols has become paramount on Long Island, particularly in Suffolk County, which lacks a centralized sewage treatment system. The white paper notes that approximately 360,000 septic tank/leaching systems and cesspools serving roughly three-quarters of county homes have increased nitrogen levels in regional groundwater 50 percent in the last three decades.
Nitrogen-enriched groundwater is “flowing into sensitive coastal environments,” the paper notes, triggering toxic algal blooms, reducing oxygen levels in coastal waters, depleting shellfish populations a wreaking other ecological havoc.
To answer this call, the CCWT was funded in 2015 by the New York State Environmental Protection Fund, which is administered by the state Department of Environmental Conservation. Lead jointly by SBU’s College of Engineering and Applied Sciences and the university’s School of Marine and Atmospheric Sciences, the center focuses public and private partners on the development and commercialization of affordable, effective water-quality restoration and protection technologies.
The NRB technology is just one of several potential water-treatment options on the center’s drawing boards, but the release of the white paper shows the CCWT is making excellent progress, according to State Sen. Ken LaValle (R-Port Jefferson), who was instrumental in obtaining that Environmental Protection Fund stipend.
“I am pleased to see that the state investments we made … are already showing great progress,” LaValle said in a statement. “The release of this initial white paper by the center illustrates the type of research that is crucial to developing the most cost-effective means for eliminating contaminants from our groundwater.”
Pilot installations of the NRB systems are now underway at a Long Island “test center,” the university said, with operations scheduled to begin this fall as part of a Suffolk County Department of Health Services demonstration program highlighting septic-treatment innovations.
After that, the potentially breakthrough technology – which is testing well in real-world scenarios in warmer climates – will hit the road on Long Island.
“The next step is to pilot them at residences,” Gobler said, “to see if they can consistently perform in more dynamic situations.”