Mohegan Lake, NY – Those lazy, hazy days that call for a dip in the lake are fast approaching. Unfortunately, the “No swimming allowed” sign has frequently been posted out by Lake Mohegan, making it impossible for residents and visitors to enjoy an afternoon by the water. Lake Mohegan has often been cited as one of the most polluted bodies of water in New York State by the Department of Environmental Conservation (DEC). The level of harmful algal blooms (HABs) has caused the beaches surrounding the community of Mohegan Lake to be closed nearly every year during the critical summer vacation season.

In an effort to rid the lake of it toxic green film, Senator Murphy and Westchester County Executive George Latimer teamed up to write a letter to Basil Seggos, Chairman of the Department of Environmental Conservation, urging the need for a coordinated rehabilitation plan. The plan would include the use of alum to restore the lake’s water quality as well as the area’s overall environment.

Through the efforts of Ken Belfer, President of the Mohegan Lake Improvement District and other local community groups, the lake has been primed as a location for a pilot project that could determine the future use of alum in lakes, ponds and other waterways throughout the state.

“It is our belief that Lake Mohegan will prove the use of alum can successfully battle phosphorous and other harmful algal blooms that plague the area,” said Senator Murphy. “Together, working as a bi-partisan team with County Executive Latimer, Ken Belfer, and the residents of the Mohegan Lake community, we can return the lake to its status as one of the major destinations for recreation in Westchester County.”

Westchester County Executive George Latimer said, “Westchester County government is committed to using innovative methods to help clean up our region’s waterways, and Lake Mohegan is one of the most contaminated water bodies in New York State. It is time we act to change that. The use of alum has, in test cases, shown to be effective in combatting the spread of harmful algal blooms, and I commend Senator Murphy’s efforts to expand its use here.”

Small amounts of alum, which were applied to the lake in 2002, provided significant improvements over the water quality. The lake community has had four different lake management consultants recommend the use of alum over the course of the past 15 years; however, the DEC has not sanctioned its use in the lake, opting instead for the use of copper sulfate.

Lake Mohegan has harmful algal blooms that have necessitated the restricting swimming in the body of water. A sample taken near the center of the lake in July 2017 indicated that the bloom was widespread and conditions along shorelines and recreational areas could be worse because the blue-green algae would produce toxins that would sicken people or kill indigenous wildlife.

There are three main causes of blue-green algae blooms – phosphorus pollution, high temperatures and a lack of natural water flow. Phosphorus pollution can be traced to human activity, with phosphorus-based fertilizers, untreated septic tanks and poor storm water management all contributors to algae issues. The nutrients from the phosphorus feed the algae, leading to blooms.