A first-of-its-kind plan could help treat wastewater on Fire Island.

Environmental advocates presented a six-year study to Suffolk legislators Monday.

One of the biggest challenges is figuring out how to get sewage off of the barrier island.

Experts says septic tanks and cesspools currently on Fire Island present risks when they overflow.

"It becomes a public health threat because it can't go anywhere," Adrienne Esposito, of the Citizens Campaign for the Environment. "It just drains into the bay or drains into the street. It's not like it's in someone's big backyard, which is what happens on the mainland."

A possible solution would be to send wastewater to the mainland through pipes under the Great South Bay.

Advocates say the next step should be a one-year feasibility study to assess costs and proper solutions.