Toxicity Testing Unit

Aquatic Water Flea;
Ceriodaphnia dubia
(Photo courtesy by USGS)
Contact Information: Nicole Wright, Program Manager Toxicity Testing Unit
As part of the RIBS program, the Toxicity Testing Unit (TTU) uses bioassays to look for toxicity in surface waters and sediments. Tests on ambient surface waters are conducted using the "water flea" (a crustacean), Ceriodaphnia dubia, to identify toxic effects on survival and reproduction. Collected sediments are also analyzed using the Microtox® toxicity testing system, which uses the bioluminescent bacterium Vibrio fischeri to look for the presence of toxicity in bottom sediments. A quick fact sheet on the method of water quality assessment using toxicity testing data is provided here: TTU Fact Sheet (PDF, 171 KB).

Luminescent Bacteria;
Vibrio fischeri
(Photo courtesy
of ENFO Project)
The TTU also provides technical oversight of Whole Effluent Toxicity (WET) testing programs required at some industrial, municipal and remediation facilities as part of the State Pollutant Discharge Elimination Systems (SPDES) permit program.