5.5. SR 08-06-2007 - Laserfiche WebLink

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The manual, funded by the Metropolitan Council along with five Twin Cities municipalities and water- shed management organizations, is available as a printed document and on the web at www.metrocouncil.org. Detailed Assessment of Phosphorus Sources to Minnesota Watersheds Minnesota Pollution Control Agency Barr prepared a report titled Detailed Assessment of Phosphorus Sources to Minnesota Watersheds in conjunction with Limno-Tech, Inc., Dr. David Mulla, and Dr. Prasanna Gowda, under the TMDL (total maximum daily load) master contract for the Minnesota Pollution Control Agency. If:r,~PoIaII" 'S='CanaoltAtleMl' Detaiied. Assessment " Concerns from the Minnesota State Legislature and other parties about the phosphorus content of automatic-dishwasher detergents resulted in legislation requiring a study of all of the sources and amounts of phosphorus entering publicly owned treatment works (POTWs) and Minnesota surface waters. To provide the MPCA with the information necessary to comply with this new legislation, Barr and our master-contract partners performed an assessment that inventoried: a) the sources and amounts of phosphorus entering Minnesota surface waters for each of the ten major watershed basins and for the entire state of Minnesota, from point and non-point sources during low (dry), average, and high (wet) flow conditions, and b) the sources and amounts of phosphorus enter- ing three different sizes and categories of publicly owned treatment works. The assessment also examined statewide variations in these annual loadings by major basin and flow condition. In addition, Barr looked at the effect of various phosphorus-source-reduction options on receiving-water quality and wastewater-treatment-facility per- formance. The assessment found that, under average flow conditions, the point-source total phosphorus contribution is 31 percent of the loadings to surface waters statewide, while non-point sources represent 69 percent. It also found that, statewide, 43 percent of phosphorus entering POTW s was from human waste and 57 percent was from non-ingested sources-with only 2.8 percent of that from automatic dishwasher detergents. Automatic-dishwasher A detailed explanation of the study, the approach and methods used, the fIndings, and the recommended concepts for lowering the amount of phosphorus that comes from both point and non-point sources can be found on the MPCA's website at www.pca.state.mn.us/hot/legislature/reports/phosphorus-report.html. deterQent: 3% Barr Engineering Company Page 19