St. Louis River - River Watch
Data Sheet for Physical and Chemical Parameters
School Name _____________________________________ Site Name ________________________________________
Latitude/Longitude (if available) ___________________________
? Temperature Transparency Dissolved Oxygen pH Nutrients
  Date Time Air (Co) * Water (Co) * cm. above disk (mg/L) % saturation* pH Nitrate
Sample 1                    
Sample 2                    
* see back side of this sheet for conversion charts  
Biochemical Oxygen Demand (BOD) Water quality expectations for our region
Initial Final Uptake Water Temp. < 18oC trout & salmon require cold water for spawning (< 90C)???????????????????????????? and for growth (< 190C)
  Date Time DO
5 Day DO
Transparency > 41 cm problems arise for stream creatures when transparency deviates from its background levels for a long time
Sample 1           D.O. > 7 mg/L the higher the D.O., the more oxygen available to support variety of life in the stream
Sample 2           D.O. sat. 80-125% D.O. saturation is a measure of how close the absolute D.O. value (mg/L) is to the equilibrium value for that temperature and air pressure
Average           pH 7.9-8.1 changes in pH can be caused by acid rain, the surrounding bedrock, and certain wastewater discharges
*BOD = initial DO - 5 Day DO Nitrate < 0.5 mg/L sources include fertilizer runoff, failing septic systems, wastewater treatment plants, and industrial discharges
Phosphate < 0.5 mg/L sources include rocks and soil, disturbed land areas, wastewater treatment plants, and fertilizer runoff
Other streamside observations of interest: BOD < 1.7 mg/L high BOD values indicate rapid depletion of oxygen by microorganisms that decompose organic matter in the water
sources: Mississippi Headwaters Board, River Watch Network, Minnesota DNR, UW Extension