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Update on Water Quality in Lake Eucha M. D. Smolen Biosystems and Agricultural Engineering OSU January 31, 2002. Why all the fuss?. The lake is clear and clean. The fishery is good. But Tulsa water tastes bad. Algae Blooms produce taste and odor
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Update on Water Quality in Lake Eucha M. D. SmolenBiosystems and Agricultural Engineering OSUJanuary 31, 2002
Why all the fuss? • The lake is clear and clean. • The fishery is good. • But Tulsa water tastes bad
Algae Blooms produce taste and odor substances that are very difficult to remove.
What are the blooms and what causes them? • Microscopic algae –sometimes in clumps, but not always • Can occur winter or summer • The culprits appear to be “bluegreens” and “diatoms”
What causes algae blooms? • Innoculation – invasive species • Lots of nutrients: • Nitrogen and Phosphorus • Sunlight • Low grazing pressure • Some competitive advantage
Nutrients in Lake Eucha • Have been increasing for the past 20 years • Very high Nitrogen concentration • Algae growth is limited by Phosphorus
ADPC&E Data Nitrate Phosphate
Nitrate in tributaries 1993-1994 Background Oklahoma Conservation Commission Data
Phos in Tribs 1993-1994 Background Oklahoma Conservation Commission Data
Nitrate at Beaty and Spavinaw 1998-01 Tulsa Metropolitan Utility Data
TP 1998-2001 Tulsa Metropolitan Utility Data
Comparison of TP 93 to 2000 1998-2001 1993-1994
Comparison Nitrate 93-00 1998-2001 1993-1994
In the lake Algae blooms Bottom of lake Tulsa Metropolitan Utility Data
Derived from monitoring data. Phosphorous Loading lbs per acre
Nutrient Loading Observed Data 7.8% 13.9% 0.7% 6% 70.8%* 0.8% *includes 24% from Dacatur
How long will it take to clean up Lake Eucha? • A long time because: • Nitrogen and Phosphorus feed the algae (and the food web). • Dead materials and sediment-bound nutrients settle out in the lake. • This storage feeds the water column periodically. • It may take years to clean out the lake.
It will clean out eventually If the supply of nutrients in runoff stops, the lake will flush.