Gov. Mark Dayton on Wednesday vetoed an attempt by a bipartisan group of lawmakers to nullify the state's wild rice sulfate standard.
Dayton said in a letter that the bill "ensures ongoing litigation that will prolong, not relieve, the current regulatory uncertainties."
"The bill you have sent me is in direct conflict with federal law," Dayton wrote, citing the Clean Water Act.
Minnesota has had a sulfate discharge limit in waters where wild rice grows since 1978, but it's rarely been enforced. The Minnesota Pollution Control Agency, at the Legislature's direction, attempted to revise the rule using updated science, but an administrative law judge rejected the move.
Lawmakers from the Iron Range introduced bills that would get rid of the longstanding standard while a longer-term solution is worked out, but Dayton said doing so would be going backward.
"Wild rice is very special to Minnesota. It is essential to the culture and spirituality of many Native American Tribes in our state," Dayton wrote.
Dayton did acknowledge that recent studies have questioned whether the 10 milligrams per liter limit was necessary on every body of water, especially when sulfate treatment can be costly for mining companies and municipalities.
He did not suggest a solution, but said he's hopeful one will be achieved.
"This Legislature can do better. Minnesotans -- including those whose cultural, environmental, and economic interests are invested in this complex issue -- deserve much better," he wrote.