ST. PAUL — The Citizens Board of the Minnesota Pollution Control Agency hears an update Tuesday on a major study on a water quality standard meant to protect wild rice.

Shannon Lotthammer, director of the agency’s environmental analysis division, said the presentation will let the board know where things stand halfway into the two-year study, which the MPCA expects to complete late next year.

Minnesota’s current standard limits sulfate discharges into waters that produce wild rice to 10 milligrams per liter. The rule has been in place since 1973 and it’s based on research from the 1940s. Mining interests and wastewater treatment plant operators have sought to loosen the standard.

After the study is complete, the agency will decide whether the current standard needs to be changed in light of the new science.