St. Louis River - River Watch

Data Sheet for Physical and Chemical Parameters

School Name _____________________________________

Site Name ________________________________________

Latitude/Longitude (if available) ___________________________

Temperature

Transparency

Dissolved Oxygen

Nutrients

Date

Time

Air (C^o) *

Water (C^o) *

cm. above disk

(mg/L)

% saturation*

Nitrate
(mg/L)

Phosphate
(mg/L)

Sample 1

Sample 2

Average

* see b

Biochemical Oxygen Demand (BOD)

Water quality expectations for our region

Initial

Final

Uptake

Water Temp.

< 18^oC

trout & salmon require cold water for spawning (< 9⁰C) and for growth (< 19⁰C)

Date

Time

DO
(mg/L)

5 Day DO
(mg/L)

BOD *
(mg/L)

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

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