New water quality standards aimed at curbing excessive algae growth in Minnesota's rivers and streams are valid, the Minnesota Court of Appeals ruled Monday.
A coalition of cities, along with a group of soybean growers, had asked the court to halt the new rules, saying the Minnesota Pollution Control Agency's rulemaking process was flawed.
The three-judge panel disagreed, meaning wastewater treatment plants that discharge phosphorus into streams and rivers will have to follow the stricter so-called eutrophication standards. The rules look at a combination of phosphorus, chlorophyll a and oxygen levels.
The MPCA updated the rules recently as part of the Clean Water Act, but cities have complained it will cost them millions of dollars to comply.
The city of Moorhead, for example, estimates it will cost $10 million to meet the new standards. Moorhead and other cities formed a group known as the Minnesota Environmental Science and Economic Review Board, which asked the Court of Appeals to review the rules.
Board officials said in a news release that the decision is disappointing but that they haven't yet decided whether to ask the Minnesota Supreme Court to review it.
Steven Nyhus, an attorney for the group, said the cities "have never disputed that these kinds of standards are necessary."
"However, the criteria that go into determining those standards can get to be very detailed, very science-specific, and depending on the outcomes, can have huge cost implications for communities that are running multimillion-dollar treatment plants," he said.
Environmental groups had urged the appeals court to uphold the rules.
"The rules are extremely important because they establish the desired condition of our rivers in terms of how much algae they have, how much phosphorus is in there growing algae and how much of that is OK and allows fish to live and thrive," said Kris Sigford, water quality program director with the Minnesota Center for Environmental Advocacy.
Besides asking a court to weigh in, cities had sought relief at the Legislature this year. A new law requires the state to conduct a cost analysis of new or recently adopted water quality standards.