Fecal coliform levels in the Mississippi have fallen significantly. The two decades shown represent the 10 years before and during the time the Twin Cities sewer separation project was under way. One major reason for this is the successful 10-year effort, completed in 1996, to separate storm from sanitary sewers in the Twin Cities. But at the same time, the challenges posed by nonpoint sources of pollution, for example runoff from cities and agricultural areas, are increasing in proportion with changing land uses and expanding population and development. The chart compares three decades of water quality in the Mississippi for four measures.
All measures indicate water quality is improving.
To deal with these newer challenges, the MPCA uses a basin management strategy. In basin management, staff assess the quality of water within drainage basins, and then work with local governments, industries, land owners and citizens to establish shared water-quality goals, determine where they re not being met, and prioritize control activities. Follow-up measurements then determine whether progress is being made in achieving the shared goals. The Minnesota River, long considered one of the most polluted rivers in the state, is on the mend. The chart compares two decades of measurements which show significant declines in the amount of sediment carried by the river at median flow rates.