Minnesota milestone river monitoring program maps

Pollution trends at Milestone sites

Phosphorus: Total Phosphorus Pollutant Levels have Decreased at Nearly Eight Out of Ten Monitoring Sites

Total Phosphorus Pollutant Levels have Decreased at Nearly Eight Out of Ten Monitoring Sites

Of the monitoring stations with valid data, 78 percent show a decrease in pollutant levels, 1 percent show an increase and 21 percent show no particular trend in either direction. Common sources of phosphorus include fertilizer, animal waste, wastewater treatment facilities and plant matter such as leaves.

Nitrogen: The Health of Minnesota's Water Bodies have been Negatively Affected by Increases in the Level of Nitrogen

The Health of Minnesota

Where valid data exist, 1 percent of monitoring stations show a decrease in pollutant levels, 75 percent show an increase and 23 percent show no particular trend in either direction. Common sources of nitrogen are plant matter like grass, wastewater treatment facilities and fertilizer. Nitrogen is measured as nitrite/nitrate.

Ammonia: Ammonia Levels have Decreased at Nearly all Minnesota Monitoring Stations

Ammonia Levels have Decreased at Nearly all Minnesota Monitoring Stations

Of the monitoring sites having sufficient data, 83 percent show a decrease in pollutant levels, 4 percent show an increase and 13 percent show no particular trend in either direction. Animal waste, fertilizer, remnants of organic matter and wastewater are some of the sources of ammonia.

Biological Oxygen Demand: Biological Oxygen Demand Levels have Decreased at Nearly all Minnesota Monitoring Stations

Biological Oxygen Demand Levels have Decreased at Nearly all Minnesota Monitoring Stations

Common sources of biological oxygen demand include animal waste, wastewater and other biodegradable materials. Where valid data exist, 89 percent of the monitoring sites show a decrease in pollutant levels, 1 percent show an increase and 10 percent show no particular trend in either direction.

Total Suspended Solids: Over 90 percent of the levels of total suspended solids have either remained constant or decreased.

Over 90 percent of the levels of total suspended solids have either remained constant or decreased.

Of the total monitoring sites that have valid data, 41 percent show a decrease in pollutant levels, 4 percent show an increase and 54 percent show no particular trend in either direction. The most consistent decreases are in the Rainy and the St. Croix River Basins. Sources of total suspended solids include erosion from construction sites and agricultural fields as well as any uncovered soils and streambank erosion.

Fecal Coliform: Decreases in fecal coliform bacteria have been experienced throughout Minnesota.

Decreases in fecal coliform bacteria have been experienced throughout Minnesota.

All of Minnesota's river basins have experienced decreases in the levels of fecal coliform bacteria. Of the monitoring sites that have valid data on fecal coliform, 82 percent show a decrease in pollutant levels, 0 percent show an increase and 18 percent show no particular trend in either direction. Fecal coliform sources include human and animal waste.