Innovative technology offers hope for toxic Agawam Lake

By Madeline Armstrong

Agawam Lake, in Southampton, is among the most polluted lakes in New York State. Each summer, the fresh water body fills with harmful blue green algal blooms that are poisonous to aquatic life, pets and humans, according to Dr. Christopher Gobler, chairman of coastal ecology and conservation at Stony Brook University. That all might be about to change, though.

The Lake Agawam Conservancy, partnering with the New York State Department of Environmental Conservation, Stony Brook University labs and the Town of Southampton, has developed a long-term HAB action plan to eliminate the toxic algae.

“Our mission is to clean up the lake from the root source of the water contamination on Long Island,” said Meghan Magyar, director and secretary of the Lake Agawam Conservancy.

These blooms are caused by the runoff of nitrogen and phosphorus pollutants into the lake. According to Gobler, these come from household septic systems, lawn fertilizers and the muddy bottom sediments of the lake. The increase of pollutants, coupled with the recent warmer temperatures from global warming, has caused the HABs in Lake Agawam to become increasingly worse in recent years.

 The number of confirmed HABs in Lake Agawam has been steadily rising since 2013. // Graph by Madeline Armstrong and numbers courtesy of the State Department of Environmental Conservation

“In 2018, we had recorded the worst toxic algae blooms in Long Island,” Southampton Mayor Jesse Warren said.

Gobler’s lab at Stony Brook University has been monitoring the lake for 20 years and has developed a new experimental treatment to address the HABs. Three solar-powered ultrasonic devices have been deployed in the lake. They shoot ultrasonic waves into the water, pushing the algae downward, making it harder for the plants to receive sunlight and, it’s hoped, mitigating the blooms. These devices are equipped with software that monitors the water quality and sends the data back to the labs at Stony Brook to be recorded. Additionally, a hydrogen peroxide-based pesticide, GreenClean Liquid, will be applied to the water, destroying the HABs’ cells and toxins.

 Three large ultrasonic devices have been deployed in Lake Agawam, equipped with monitors that will record the water quality in real time. // Photo courtesy of the Lake Agawam Conservancy.

“No one’s done it together [used ultrasonic devices and hydrogen peroxide to treat HABs] in all the world,” said Janice Sherer, planning and governmental adviser for the Lake Agawam Conservancy.

The toxic blue green algae is present year-round in Agawam Lake, but becomes more problematic during the summer when the blooms are formed in May and June, reaching their peak season during August and September. So, the treatment was started in April and will be conducted for the duration of the summer.

The “DEC will be evaluating the effectiveness of [the treatment] during the summer,” said Kevin Frazier, director of operations for the DEC. “We expect to have final results to share in the fall.”

This treatment is innovative and experimental, potentially changing the way HABs are attacked in other bodies of water moving forward. “If proven effective, the treatment techniques could be applied to other water bodies across the state with similar conditions,” said Frazier.

 The number of HABs in water bodies across New York State has been steadily rising since 2012. // Graph courtesy of the State Department of Environmental Conservation.

Agawam Lake is not unique in its water pollution. HABs are a growing problem across Long Island, especially in Suffolk County.

“Unfortunately, Suffolk County has more blue green algae cases in different lakes and fresh water bodies than any place else in New York,” said Adrienne Esposito, executive director of Citizens Campaign for the Environment, “and that’s a claim to fame we do not want.”

“There’s only so much time that we have,” Sherer said. “These water bodies are on the brink of collapse.”

While this new treatment is a big step in a positive direction, Gobler said there is much more that can be done to combat the HABs. “This is a short-term band-aid to address the immediate public health threat these events represent,” he said. “We are engaged in the equally important [if not] more important work to reduce the flow of the pollutants… into the lake.”

The influx of nitrogen and phosphorus into the water has caused severe contamination in Lake Agawam. // Photo courtesy of Christopher Gobler

The two biggest contributors to excess nitrogen in the lake are the pollutants released from septic tanks and lawn fertilizers. Magyar encourages home and business owners to upgrade their septic systems to low nitrogen septics and urges professional landscapers to eliminate synthetic nitrogen fertilizers.

In light of the increased water pollution, Suffolk County has enacted a septic replacement program, encouraging homeowners and businesses to update their septic systems by rebating all costs. “People can actually get up to $30,000 in grants to change their septic systems and use a new technology that will treat the sewage before it leeches back out into the ground or other water bodies,” Esposito said.

According to Sherer, several hundred people in Southampton have already switched to one of these denitrifying septic systems.

Additionally, testing is being done to see if dredging the lake would further combat the algal blooms. “A lot of the phosphorus comes from the bottom of the lake,” Warren said. “So, dredging would be a big solution for eliminating the phosphorus.”

 The number of HABs has increased greatly in water bodies across New York State, threatening the future of water safety. // Photo courtesy of the State Department of Environmental Conservation

“This is a moment of crisis,” said Magyar, “and Lake Agawam is a great place for us to try and find solutions.”