The study measures levels of pollutants – in this case, phosphorus, bacteria, sediments and nitrate – to ensure they comply with safety standards. The study's data were compiled based on a decade's worth of water-quality data, as well as fish surveys, stressor identification investigations and stakeholder input.
Calling for a range of 31 to 39 percent reductions in phosphorus for Lake Winona and flow-dependent reductions for the Whitewater River and its tributaries, the report offers pollutant-reduction strategies, such as wastewater-discharge limits, urban stormwater controls and updated agricultural practices, among other measures.
These strategies and reduction goals are important for this area of Minnesota, which is typified by a karst landscape, meaning the porous bedrock is only covered by a thin layer of topsoil. This means pollutants are easily introduced into the groundwater.
EPA Testimony Statements -- http://www.epa.gov/ocir/hearings/testimony/113_2013_2014/2013_2.htm