Department of Administration
658 Cedar St., Suite 300, St. Paul, MN 55155 651-296-6398
Page last modified: Monday, 04-Mar-2013 15:10:15 CST
Saturday May 18, 2013 02:45:29 AM
|Dept. of Administration / Office of Geographic and Demographic Analysis|
Minnesota Milestones Links
Indicator : Water quality in lakes and rivers
Rationale: The suitability of Minnesota's lakes, rivers and streams for swimming and aquatic life is a good indicator of water quality.Percentage of monitored lakes acres suitable for swimming
Data source: Minnesota Pollution Control AgencyPercentage of monitored river miles suitable for swimming
Data source: Minnesota Pollution Control AgencyPercentage of monitored river miles supporting aquatic life
Data source: Minnesota Pollution Control Agency
About this indicator: Of the sampling of lakes and rivers that are monitored, more lake acres became unswimmable, fewer river miles supported aquatic life, but more river miles became suitable for swimming between 1994 and 2000. Defining a body of water as swimmable is based largely on the presence of fecal coliform and E-coli bacteria, while suitability for aquatic life is based on the presence of toxins (such as ammonia, chlorine and heavy metals), water clarity and the availability of oxygen in the water.
The percentage of monitored lake acres suitable for swimming slipped from 79 percent in 1994 to 64 percent in 2000. The percentage of monitored river miles supporting aquatic life dropped from 73 percent to 65 percent during the same six years. However, the percentage of monitored river miles suitable for swimming rose from a low of 39 percent in 1994 to 62 percent in 2000.
Things to think about: The 1972 federal Water Pollution Control Act set a goal of ensuring that U.S. waters are "swimmable" and "fishable." Minnesota has made progress in controlling end-of-pipe discharges from wastewater treatment plants and industrial plants. However, the challenges posed by sources of pollution such as water runoff from cities and agricultural areas are increasing.
Technical notes: In 2000, the most recent year for which data is available, the figures are based on monitoring 53 percent of lake acres and 1.12 percent of river miles for their swimmability, and not quite five percent of river miles for their ability to support aquatic life. The Minnesota Pollution Control Agency reports its findings on about one-third of Minnesota's 10 watersheds every two years.
Other related indicators:
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