At Sylvester Manor: Constructed Wetlands Project On a Roll
The surest sign of the thaw of spring isn’t the popping of the first flowers of the year. It’s the sound of track excavators moving the newly thawed earth.
Over at the Sylvester Manor Educational Farm on Shelter Island this month, work is well underway on Suffolk County’s first non-proprietary constructed wetlands septic system, a project designed to remove up to 90 percent of the nitrogen in the effluent from the farm’s 1737 Manor House, where much of its staff lives.
The project is an early step in the farm’s master plan to be the site of innovative environmental experiments while continuing to honor its history, said Sylvester Manor Planning & Conservation Consultant Sara Gordon on a tour of the project in early April.
“It’s a 21st Century project with a narrative connection to the core of the site, lined up with the boxwood allée to the house, through the garden,” she said. With the excavation, she added, the farm was also able to bury some electrical lines across the field used for many of its educational programs.
The project was funded by the Suffolk County Drinking Water Protection Program, a New York State Community Capital Assistance Program grant, an education grant from the Long Island Community Foundation, and by donations from community members and board members, farmers and staff at Sylvester Manor.
If this pilot is successful, it could pave the way for approval of this technology at other sites in Suffolk County.
In the meantime, said Ms. Gordon, the Suffolk CountyDepartment of Health has required the farm to install a traditional backup septic system in case the constructed wetland fails.
The project is being constructed by Shelter Island Sand & Gravel’s Peder Larsen, who has built most of the island’s septic systems for the past 20 years, under the engineering guidance of New Jersey firm Natural Systems Utilities.
Ms. Gordon said Mr. Larsen hopes to be at the forefront of Long Island’s nascent alternative septic system industry, made possible by changes last year to Suffolk County’s sanitary code encouraging alternatives to traditional septic systems.
Researchers from Stony Brook Southampton’s Center for Clean Water Technology have also been involved in documenting the effectiveness of the system.
This project circulates wastewater through a 36-inch layer of gravel and roots from the wetland, converting ammonium from urine to nitrates and nitrites. During this process, aerobic microorganisms attached to the gravel and roots help further process the wastewater, which then enters a saturated layer where further denitrification occurs. The wastewater can then be recirculated back to the septic tank, where carbon from waste can help promote further denitrification.
The system is dependent on people using the bathrooms in a converted shipping container adjacent to the wetlands to help generate flow, especially before the height of the farm’s summer season. It is expected to be online by the end of April.
“We welcome visitors to come make a contribution to the project,” said Ms. Gordon. “We literally want peoples’ flow. It’s pretty unusual to feel like you’re making a contribution when you’re using the bathroom.”
The Manor House usually houses about eight staff members, who currently cook and bathe in the house, which is adjacent to Gardiners Creek.
In addition to the public restrooms, a second container building houses cooking, commercial laundry and shower facilities for the staff.
“They’ll sleep in the Manor House and they’ll generate most of their flow here,” said Ms. Gordon. “If this project works, we will replace the containers with residential facilities. It’s part of the early stages of our master plan.”
The Long Island Community Foundation grant will allow the farm to use the system to teach students about the cycle of waste through the ecosystem, something that students at the Shelter Island School may soon have an intimate familiarity with. The school is also installing an innovative new septic system.
“This whole place is kind of an experiment,” said Ms. Gordon. “We’re very conscious of our impact on the community, and we want to preserve what’s important.”