Dr. Jennifer Bouldin, director of the Ecotoxicology Research Facility and associate professor of environmental biology at Arkansas State University, and graduate student Molly Kennon used three tests to see any indicators of toxicity in the water and sediment samples collected from the lake and around Mayflower.
Two tests were used to test the water from the six sites. Both are Environmental Protection Agency-certified Whole Effluent Toxicity — or WET — tests. According to the EPA, WET tests are usually used to measure wastewater’s effects on specific test organisms — in this case C. dubia and fathead minnows — ability to survive, grow and reproduce.
WET tests are used by the National Pollutant Discharge Elimination System to determine facility permits.
The ASU Ecotoxicology Research Facility is an EPA-certified lab offering WET testing for local municipalities and industries. The same tests used for those clients was used on the Mayflower samples.
"When we do point-source discharges like we do with municipalities and things like that, that’s what they recommend," Bouldin said. "Their protocol is for the C. dubia and the fathead minnow for warm freshwater species."
Bouldin said it is important to run both the C. dubia test and the fathead minnow test. The C. dubia are more sensitive to the elements expected in the Mayflower samples, but it is important to run both in case there is something unexpected.
"Following that with looking for any kind of contaminant is just good practice because it’s a standardized technique," she said.
The sediment was tested with bloodworms that burrow and ingest the material. The bloodworms are not a WET testing technique because they do not test water, but Bouldin said it is an EPA-recognized organism.
"They’re just not described for the NPDES permit testing because obviously that’s aqueous only and this is sediment," she said.
The C. dubia used in the test were from an EPA lab. The fathead minnows and bloodworms were cultivated in the Ecotoxicology Research Facility.