Lake Catherine Biological Assessment and Mixing Zone Study
Lake Catherine, Arkansas
At the request of the Arkansas Department of Pollution Control and Ecology (ADPCE), a study was conducted to determine if the Outfall 001 effluent at a metals production facility was having an impact on the aquatic biota in Lake Catherine and to determine the mixing zone and critical dilution for biomonitoring. The study involved an integrated physical, chemical, and biological approach including the following:
A dye study to define zones in Lake Catherine influenced by the Outfall 001 discharge;
Benthic invertebrate collections, identifications, and analyses to identify effluent effects, if any, on the benthic community;
Habitat evaluations to determine if habitat is limiting for benthic invertebrates;
In situ dissolved oxygen, conductivity, pH, and temperature measurements in the water column to define environmental conditions during the study; and
Model stimulation, using the EPA model CORMIX, to predict effluent dilution under a variety of environmental conditions.
Both Hester-Dendy's and rock baskets were used and evaluated prior to selecting rock baskets as an artificial substrate for benthic invertebrate collections. The study results demonstrated that the effluent from Outfall 001 was not impacting the aquatic biota in Lake Catherine. The ADPCE accepted the proposed mixing zone definition and associated critical dilution for biomonitoring.
Little Rock, AR
● Fayetteville, AR
● Baton Rouge, LA
● Jackson, MS
