Wild rice is a delicate plant, valuable to those who harvest it, and a habitat for much wildlife, but Minnesota’s state grain is stirring up debate at the state Capitol.

Though water quality standards to protect wild rice were established almost half a century ago, the Minnesota Pollution Control Agency only began consistently enforcing them six years ago. Now, those regulations are frustrating iron and copper-nickel mining operations that have to filter their wastewater, which could cost billions of dollars.

In response, some state leaders, like Sen. David Tomassoni, DFL–Chisholm, have introduced bills to the state Legislature to address the issue.

“All of the sudden we’re endangering peoples’ jobs and asking tax payers to pay billions of dollars to enforce this,” said Tomassoni, who introduced a bill last month to suspend the standard. “It doesn’t make sense.”

He said the MPCA needs to identify exactly what waters in the state are wild rice waters, clarify the process to add new waters to that list and further confirm the relationship between water quality and wild rice growth before it can enforce a standard.

But MPCA assistant commissioner for water policy Rebecca Flood said that could take years.

The agency’s first priority is meeting the federal Environmental Protection Agency’s Clean Water Act rules, she said, but she understands the financial concern.

“It’s not the Pollution Control Agency’s objective to make municipalities go bankrupt because of the need to meet permit requirements,” Flood said. “We really are working hard with permittees to not have them be financially stressed to the point that it would drive them out of business.”

But many people, like University of Minnesota-Duluth American Indian studies professor Erik Redix, say protecting wild rice from endangerment is worth the cost.

Redix has harvested wild rice since he was a teenager, he said, and the grain remains a primary food source for his family.

While harvesting, he said he’s noticed that some rice beds will fluctuate from year to year in their productivity.

“I assume that that’s just due to the natural cycle of the plant, but you don’t know if it’s something else [like water quality],” Redix said.

Minnesota Department of Natural Resources records reported that there were nearly eight times less harvesting licenses issued from the 1960s to the 2000s, which could mean there’s less wild rice in the state, but it can’t be confirmed. State wild rice waters weren’t identified, recorded or studied until 2008.

After the waters were identified, the 1854 Treaty Authority, an inter-tribal resource management agency, alerted the MPCA that several of them were downstream from mines.

Only after that did the agency start enforcing the standard consistently through permits.

State legislation in 2011 required the agency to validate the standard through research. So it commissioned the University of Minnesota to study the correlation between sulfate levels and wild rice.

Since then, research has been mounting to show the relationship between sulfate — which is the component of wastewater regulated by the standard — and wild rice survival.

But the relationship is complicated, said UMD adjunct biology professor John Pastor, who researched sulfate and wild rice for the MPCA.

Sulfate is released when oxygen hits rocks in mines during the mining process, he said, and then it travels into nearby water. When sulfate eventually settles in the sediment at the bottom of lakes, bacterial decomposers sometimes convert the sulfate to a new form called sulfide, Pastor said.

While researchers like Pastor have found that sulfate alone doesn’t impact wild rice growth even at concentrations much higher than the state standard, he said it’s harmful to wild rice when converted to sulfide, even at very low concentrations.

Research in state lakes and control tanks found that the more sulfides are in water, the less wild rice is produced.

“You really can’t, from our data, raise the concentration of sulfate all that much before the sulfide starts to become toxic,” Pastor said.

Sulfate content in mining wastewater can be up to hundreds or thousands of parts per million, but the standard requires the operations to reduce the content to just 10 parts per million, which is expensive.

Iron, however, can keep sulfate from turning to sulfide, Pastor said. But more research needs to be done to tell where iron is stopping that conversion in lakes and how that affects wild rice growth.

The MPCA will present all the research it has gathered up until now that validates the standard to the state Legislature at the end of the month. But Tomassoni’s and other bills could still suspend the standard.

If the standard were suspended, it would save mining companies and taxpayers’ money, but it would interfere with federal EPA standards — which still have the final say.

Redix said he worries that the more society industrializes, the less protection there will be for wild rice.

“It’s something that’s really important,” he said. “It should be studied, and these rules should remain in place to protect this resource by any means necessary.”