A simple layering of wood chips and sand could be one solution to Suffolk County’s wastewater pollution problem, according to new research out of Stony Brook University’s Center for Clean Water Technology.
The center is studying an inexpensive, low-maintenance biofilter that uses these natural materials to remove as much as 90 percent of the nitrogen in the wastewater from septic systems.
Researchers at the center presented their findings at a symposium in Stony Brook on Thursday.
About 360,000 homes in Suffolk County are on septic systems or cesspools, and the waste is thought to contribute about 70 percent of the total nitrogen to the area’s waterways. Excess nitrogen in surface water leads to harmful effects such as decreased oxygen levels, harmful algae blooms and a weakening of the coastal marshes that serve as buffers during storms.
The nitrogen-removing biofilters operate by using gravity to send waste through a layer of sand and an underlying layer of saturated wood chips mixed with sand. They would be installed as an added step to a standard septic system.
The system is being tested in Massachusetts, but it has not yet operated on Long Island.
“We want confidence these will work on Long Island,” said Chris Gobler, a professor at Stony Brook University’s School of Marine and Atmospheric Sciences and co-director of the center.
To that end, Gobler said sand and wood from Long Island was sent up to Massachusetts to be tested in systems there.
The system is set to be tested in Suffolk County in the fall, in conjunction with the county Department of Health, he said.
In addition to nitrogen, the system also appears to rid wastewater of personal care products and pharmaceuticals, said Harold Walker, another co-director of the center and professor and chair of Stony Brook’s Department of Civil Engineering.
Walker said the design of the system also means “they are low maintenance and require little energy to operate.”
The move comes as environmentalists and policymakers seek to find ways to tackle the nitrogen problem in the county.
Earlier this year, Suffolk County introduced a proposal to create an aquifer-protection district funded with proceeds from a fee on water usage. The county temporarily halted the idea this month after facing opposition from state lawmakers, who would have needed to pass a bill allowing voters to weigh in on the fee.