1. Gary Cooper & Stefanie Harrison
Turbidity
Gary Cooper & Stefanie Harrison

2. Definition
Measure of cloudiness in the water

3. Measuring Turbidity NTU-Nephelometric Turbidity Units
JTU-Jackson Turbidity Units

4. Acceptable Ranges of Turbidity
Designated Use Acceptable Ranges
Recreation NTU (Awwa, 1990)
Aquatic Life < 50 NTU instantaneously or
< 25 NTU for a 10 day average
< 10 NTU for trout waters or                      < 25 NTU for streams (non-trout waters) or                      < 50 NTU for lakes and reservoirs
(non-trout waters)
Human Consumption to 5 NTU (up to 5 NTU is allowed if
the water supplier can demonstrate that
this level does not interfere with:
1) disinfection 2) maintenance of a
disinfecting agent 3) microbiological
determination

5. Sources Storms/Flooding People polluting water Leaves
Soil Erosion (from building/road construction, forest fires, logging, mining)
Waste Discharge
Urban Runoff
Household pets playing in water
Algal growth
Bottom feeders (carp)- stir up sediments
Decaying plants/animals

6. Impact on Organisms

7. Effects of Turbidity Clogs fish gills Decreases growth rates
Decreases resistance to disease
Prevents egg and larval development
Smothers eggs of fish and aquatic insects
Really high levels can cause death

8. Sources www.fivecreeks.org/monitor/turbidity.html
info/turbid.html
waterontheweb.org/under/waterquality/turbidity.html