ST. PAUL— Gov. Mark Dayton is siding with U.S. Steel in a fight over water pollution standards for its taconite facility in Mountain Iron.

In an interview with Minnesota Public Radio, Dayton says the current standard is out of date and enforcing it could be “catastrophic” for northeastern Minnesota and its mining interests.

A 1973 state law limiting the amount of sulfates discharged into lakes and streams that produce wild rice went largely unenforced until a few years ago. The Minnesota Pollution Control Agency is expected to issue a draft of new rules around the end of March.

U.S. Steel has lobbied the Legislature to delay implementation. Enforcement would mean huge costs for new pollution controls. Defenders of the standards warn that easing them could provoke action by the U.S. Environmental Protection Agency.