A legal move was made Wednesday to force the state and National Grid to update equipment at two Long Island power plants.

Environmentalists filed a lawsuit against the New York State Department of Conservation and National Grid, claiming that a power plant in Northport and a similar one in Island Park need major upgrades to their cooling systems.

They say the antiquated equipment in the cooling systems are killing fish. 

Environmentalists say the fish die when they are sucked in with the cooling water that cycles through the plant.

Four years ago, the state DEC issued a policy requiring new and existing plants to upgrade their cooling systems, but environmentalists say that hasn't happened yet.

Environmentalists say that at other plants in other parts of the country, the cost of an upgrade comes to between four and 20 cents a month per customer.

News 12 received a statement from National Grid saying it is currently working with the DEC to study the impact that its cooling systems have on aquatic life.