Wild rice research: The results could affect you

Iron Range employers and municipalities will face devastating costs if the standard is not updated.

The only technology that will meet that standard is membrane treatment (e.g. reverse osmosis). Studies of currently operating systems show that municipalities would need to impose huge water bill increases (a typical increase might be $130 per month per household) to build and operate the required systems.

Predicted costs to treat a single discharge from a mine are on the order of $120 million in capital costs, and tens of millions of dollars a year in operation and maintenance costs.

Given naturally occurring sources of sulfate, treatment on this scale may still not meet the current standard where the wild rice grows.

The Minnesota Chamber of Commerce and others are working with the Minnesota Pollution Control Agency (MPCA) to conduct modern research on the effects of sulfate on wild rice. While sulfate is a nutrient for all plants and is naturally occurring in all waters, the current standard is antiquated, based on field surveys conducted in the 1950s and ‘60s, and were not intended for setting a water quality standard.

In 2011, the legislature recognized the problem, appropriating $1.5 million for modern scientific research on the effects of sulfate on wild rice and directing the MPCA to use that research to update the standard. The MPCA contracted with the University of Minnesota Duluth and Twin Cities professors to conduct the research.

In December 2013, the MPCA released the results of five studies, in addition to multi-year field surveys and an additional study conducted by the Minnesota Chamber and its members.

The research and field studies by the MPCA and the Minnesota Chamber show:

1. Sulfate is not toxic to wild rice except at very high concentrations (e.g. 1,600 mg/L to 2,500 mg/L). Both the MPCA and MN Chamber studies agree on this.

2. Field surveys reveal that wild rice grows well in natural waters containing much higher sulfate concentrations than 10 mg/L. Healthy wild rice was found in water with sulfate as high as 1,000 mg/L.

3. Any negative impacts to wild rice from sulfate are mitigated by the presence of iron in the water and sediment where wild rice grows.

Unfortunately the MPCA has developed a hypothesis regarding sulfide impacts to wild rice. The MN Chamber believes that the scientific studies do not support that hypothesis, that the studies are technically flawed and additional research is needed. The MN Chamber believes that the correct sulfate standard should be 1,600 mg/L or higher.

What can you do?

Stay informed.

Thank your legislator for their ongoing engagement.

Encourage leaders in your community to get involved.

We all want to protect wild rice. Let’s make sure that the MPCA’s standards are based on sound modern science.