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Measures of Water Quality. Introduction. The United States Geographical Survey monitors waterways all over the country, tracking all of the most important factors that have an impact on water quality . . Temperature. Taken and recorded every time a sample is gathered.
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Introduction • The United States Geographical Survey monitors waterways all over the country, tracking all of the most important factors that have an impact on water quality.
Temperature • Taken and recorded every time a sample is gathered. • Important indicator of changes in water quality • All aquatic organisms have a preferred temperature range • Influences water chemistry – higher temperatures allow for more dissolved minerals, less dissolved gases (like Oxygen) • USGS data for streams and rivers in Maryland
Color and Odor • Can indicate other measurements/tests needed • Should be continually monitored & logged for changes • Should be described with every sample taken
Turbidity • Measure of clarity • High turbidity causes lakes to fill in faster, places for pollution to attach, reduced plant productivity, habitat destruction (from sedimentation) • Measured with a “turbidity tube” (at right) • USGS Data for Maryland
pH • Measured on a scale of 0-14, 7 is neutral. • pH reading of 5 is 10X more acidic than pH of 6 • Determines the solubility of water, and the availability of nutrients to organisms • USGS Data for Maryland Streams & Rivers
Alkalinity • Measure of water’s ability to neutralize acid • Important because it indicates how healthy a stream is, how it resists changes • Higher readings are better • Measured in PPM of Calcium Carbonate CaCO3
Nutrient Balance • Nitrates • Critical for plants & animals • Denitrification (getting Nitrogen gas from nitrates) = important task in ecosystems • Nitrate load being too high causes algae blooms • Phosphorus • Also critical for plants and animals • Often the “limiting factor” in streams • Too much phosphorus can also cause algae blooms
Dissolved Oxygen (DO) • Cooler water can hold more dissolved Oxygen gas (O2) • 10 PPM is optimal, but not necessary for life • DO readings should be taken every few days, at the same time each day. • USGS Data for Maryland Streams
Fecal Bacteria • Presence indicates animal/human pollution • Not always an indicator of an unhealthy stream, just of poor drinking quality • Testing generally indicates presence, not levels
Works cited • http://ga.water.usgs.gov/edu/temperature.html • http://ga.water.usgs.gov/edu/phdiagram.html • http://www.nsf.org/consumer/drinking_water/dw_well.asp?program=WaterTre#problems • http://ga.water.usgs.gov/edu/dissolvedoxygen.html • http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&lv=list.listbyalpha&r=216594&subtop=200 • http://ga.water.usgs.gov/edu/turbidity.html • http://water.epa.gov/type/rsl/monitoring/vms510.cfm