Large river water quality monitoring

Today, Metropolitan Council Environmental Services monitors more than 150 river miles in the Twin Cities metro area via 15 long-term monitoring sites on 4 rivers: the Mississippi, Minnesota, St. Croix, and Crow rivers. We monitor these large rivers for a variety of physical, chemical, and biological variables. The goal is to document long-term changes in water quality and assess and characterize biological communities and riverbed sediments.
Large river water quality monitoring allows us to:

• Measure compliance with state water quality standards and criteria
• Meet National Pollutant Discharge Elimination System (NPDES) permit requirements
• Assess the operations of our wastewater treatment facilities
• Determine the biological health of large river ecosystems
• Obtain information on the sources and water quality impacts of nonpoint source pollutants
• Document long-term trends and changes in water quality

Large River Water Quality Monitoring Sites

Note: Automatic monitoring stations measure temperature, pH, dissolved oxygen, and specific conductivity at 15-minute intervals. Biological monitoring is conducted at 8 sites (6 on the Mississippi River and 2 on the Minnesota River) where macroinvertebrates are collected and sent to a lab for identification.

Water quality paramters and frequency of measurement

(Frequency is weekly during March – October and biweekly during November – February)
 

Frequency	Analyte
Bi-Weekly	Biological Oxygen Demand, Total (In-situ 5-day) Biological Oxygen Demand, Carbonaceous (In-situ 5-day)
Weekly	Temperature Dissolved Oxygen pH Specific Conductivity Turbidity Chloride, Total E. coli Fecal Coliform Chlorophyll-a Nitrogen - Ammonia Nitrogen - Nitrate Nitrogen - Nitrite Nitrogen, Total Kjeldahl Nitrogen, Total Kjeldahl, Dissolved Phosphorus, Ortho, Dissolved Phosphorus, Total Phosphorus, Total Dissolved Solids, Total Suspended
Quarterly	Alkalinity, Total Ions - Calcium, Dissolved Ions - Magnesium, Dissolved Ions - Silica, Dissolved Ions - Sodium, Dissolved Ions - Sulfate, Dissolved Ions - Potassium, Dissolved Solids, Total Dissolved Carbon, Total Organic Hardness Trace Elements - Aluminum, Total Trace Elements - Antimony, Total Trace Elements - Arsenic, Total Trace Elements - Beryllium, Total Trace Elements - Cadmium, Total Trace Elements - Chromium, Total Trace Elements - Copper, Total Trace Elements - Iron, Total Trace Elements - Lead, Total Trace Elements - Mercury, Total Trace Elements - Nickel, Total Trace Elements - Selenium, Total Trace Elements - Silver, Total Trace Elements - Thallium, Total Trace Elements - Zinc, Total

Additional resources

• EIMS for data on monitoring and water quality
• River monitoring reports
• 2018 Regional River Water Quality Report