FBSR, as well as public water suppliers who utilize the Big Sioux River and its associated aquifer for drinking water sources, originally petitioned South Dakota’s Department of Environment and Natural Resources (DENR) to enforce a nitrate limit of 10 ppm for the Agropur wastewater discharge permit.

Ten ppm is the current safety standard for drinking water, and twice as high as some public health groups and research suggests. The DENR set a higher limit of 18 ppm (nitrates) for Agropur, which we can only assume Agropur is working to reach as they solve their start-up problems. An important lesson is that Agropur's discharge is not the only problematic rate of nitrate discharge on the Big Sioux River. Smithfield Foods and the Sioux Falls Wastewater Plant are expanding their discharges, and indications are that DENR will issue new discharge permits for them at 50 (nitrates) ppm, which dramatically exceeds acceptable health levels. Both plants have the financial capability of meeting a safety level of 10 ppm.

Make your voice heard and contact the DENR to ask for a discharge permit of 10 ppm.

The Big Sioux does not have an unlimited capacity to assimilate whatever pollution we dump into it.

https://www.sdnewswatch.org/stories/expanded-s-d-cheese-plant-violates-pollution-limits/