Two wastewater treatment plants in southwest Ohio are appealing the state's order to reduce the amount of phosphorus that goes into the Great Miami River.
Dayton and Montgomery County say changing their operations to comply with the new rules could cost up to $2 million. They say those costs would need to be passed onto water customers.
The Ohio Environmental Protection Agency earlier rejected a request to delay setting the limits. The state EPA says its research shows the plants are sending too much phosphorus into the river during the summer and that can add up to more toxic algae blooms.
The Great Miami River flows through the southwestern part of the state and into the Ohio River, which last year saw a 600-mile algae bloom.
