Nassau must pay tens of thousands of dollars in fines over environmental violations at its Bay Park, Cedarhurst and Lawrence sewage-treatment plants under the terms of an agreement with state environmental officials the county signed this week.

The order on consent by the state Department of Environmental Conservation covers violations involving the effluent from the Cedarhurst and Lawrence plants, which the county took over from those villages in a move to consolidate sewage treatment in 2008.

It also includes violations over the county's air-contamination permit at its larger Bay Park facility, which processes about 50 million gallons of sewage a day and serves more than 500,000 people.

MapSuffolk sewage statusMore coverageWater quality on Long Island

The agreement calls for Nassau to pay $40,000 in fines and spend $59,000 on projects to benefit the environment.

The consent order takes effect the day the DEC signs it. A DEC spokesman said Thursday the agency would sign it "shortly."

While the county had planned to shut down the Lawrence and Cedarhurst plants and reroute the sewage to Bay Park in East Rockaway, those plans were halted after Bay Park sustained heavy damage during superstorm Sandy in 2012.

advertisement | advertise on newsday

Since then, the county has continued operating the two smaller plants, which together treat about 2 million gallons of sewage a day, Chief Deputy County Executive Rob Walker said. But effluent from the two plants has not met water-quality standards, leading the DEC to bring the enforcement action against the county.

Under terms of the consent order, the county agreed to divert the sewage from the two plants to Bay Park by the end of October and decommission the plants by the end of the year.

Walker said the infrastructure already is in place to begin sending the sewage to Bay Park, which is permitted to treat up to 70 million gallons a day.

"We literally could hit the switch," he said. Once the diversion is complete, the county will begin dismantling the two plants, he said.

Michael Martino, spokesman for United Water, the private company that is operating Bay Park, said the impact of the additional sewage on the facility "will be minimal."

The consent order also addresses violations regarding an air-contamination permit at Bay Park. That permit relates to the generators the plant must use for electricity. While there are electric transmission lines to the plant, they only provide a fraction of the amount of power the facility needs to operate, Walker said.

The consent order maintains that the county filed its renewal application late and included neither the backup diesel generators it installed before Sandy in the application nor nine natural gas generators it installed in 2014 -- although it informed the state about both moves.

It also took no action to offset the contamination created by the natural-gas generators, according to the document.

advertisement | advertise on newsday

The order allows the county to continue to operate Bay Park under the terms of its expired air permit until a new one is issued, and it requires that the county inform the state within 60 days about its ultimate plans on how to power the facility.