Almost everything about Southampton is tony. Its residents (Calvin Klein, David Koch, Tory Burch). Its branzino (especially the $53 oven-roasted version from Sant Ambroeus). And especially its real estate, where a 2,000-square-foot cottage on a quarter of an acre in the village is currently listed for $2.4 million.

But there is one rather significant blight on this charmed corner of civilization: cyanobacteria. This blue-green algae is blooming and blooming and blooming some more in the once majestic Agawam Lake, which lies at the center of the village, connecting its downtown area to the southern coastline.

Although multi-million-dollar homes surround its borders, Agawam Lake isn’t exclusively the province of the super-rich. Before exposure to its waters could cause a host of maladies, ranging from vomiting and diarrhea to rashes and breathing difficulties, it was a popular spot for boating and fishing. A ferry dating back to the 1800s even used to taxi local families across its waters.

Despite many valiant attempts at filtration, the algae problem persists.

But for years it has been the subject of fear and loathing, and it’s now one of the most polluted lakes in New York. The algae was first detected in 2003, leading to a host of efforts from local nonprofits and a visit from then governor Andrew Cuomo himself to restore the lake’s eco-system and water quality. In 2012, local news outlets reported that a dog had died after drinking the water of Georgica Pond, which is also contending with a serious algae problem.

“On Long Island, there is no freshwater body that has had blooms as intense or consistent as Lake Agawam,” says Christopher Gobler, Ph.D., a professor at Stony Brook University and Agawam Lake’s leading expert. Why is an area known for its affluence and scenic landscapes plagued with such a pollution problem, and why does it persist?

Born and raised in Southampton, Brenda Simmons has witnessed Agawam Lake’s demise firsthand. She recalls that neighborhood boys used to catch fish there in the 50s and 60s. “Why isn’t it clean by now, with all the money that I know had been poured into that?” asks Simmons.

This mobile harvester system removes algae off of Agawam Lake’s surface.

Several partnerships between village, town, and state officials have sprung up to combat the problem. The Lake Agawam Conservancy nonprofit, Stony Brook University’s School of Marine and Atmospheric Sciences (the department in which Dr. Gobler works), and the Southampton Village Clean Water Committee have developed initiatives to mitigate present algal blooms and sources of contaminants.

But there’s no easy remedy. The biggest chemical contaminants that cause algal blooms—excess nitrogen and phosphorus—have been accruing for decades, thanks to fertilizers and chemicals that ensure the lawns of the East End are as lush and verdant as possible. These contaminants have accumulated to form a six-foot layer of lake-bed sediment, from which they are periodically released back into the water. Researchers are completing a study this summer that will bring them one step closer to dredging the mud—a necessary measure to fully clean the lake—and Dr. Gobler remains optimistic that proper funding will be available when it is needed.

But sewage is really at the heart of this matter. Southampton lacks a centralized wastewater system; instead, around 75 percent of the homes rely on old septic systems that involve antiquated cesspools, which can leach nitrogen into the surrounding underground aquifers and water tables.

“Why isn’t it clean by now, with all the money that I know had been poured into that?”

As those water tables rise, nitrogen contamination will increase, further polluting all of the local water, from marshes, lakes, and bays to the Hamptons’ drinking-water supply. “Until all those septic systems are upgraded, everything else is a Band-Aid,” says Meghan Magyar, a director and secretary of the Lake Agawam Conservancy.

But such an overhaul takes years of planning and execution, and the village is still in its early stages of rolling out a plan. In 2019, Suffolk County committed to eliminating cesspools and older septic systems through a $4 billion investment, allocated over the next 50 years.

If that seems expensive, it’s because the project is massive—Southampton dates back to 1640, and, accordingly, its narrow, meandering roads pose myriad problems for the design of a centralized sewage district. Suffolk County, which includes the Hamptons and Montauk as well as larger towns such as Huntington, Brookhaven, Babylon, and Islip, is offering rebates to homeowners who update their systems, but a recent report in The Guardian claimed that only 773 have done so, with 200,000 still in need of overhauls.

Meanwhile, the sewage crisis has been exacerbated by the pandemic. Wealthy New Yorkers decamping to the Hamptons placed even more strain on the existing infrastructure. Accordingly, those homeowners who didn’t realize that the tanks must be emptied regularly (when their homes are inhabited full-time) experienced septic meltdown. A putrid sinkhole in the backyard, or raw sewage spewing from a faucet, can really put a damper on your dinner party.

So, for the time being, don’t even think about walking Fifi around the shores of Agawam Lake. As any good Southamptonite will tell you, everyone who’s anyone only goes to the ocean beaches anyway.

Anisah Abdullah is a Brooklyn-based writer