Home > Services We Offer > Services We Offer by Method Group > Specialty Analyses > Whole Effluent Toxicity Testing
Whole Effluent Toxicity Testing

Whole Effluent Toxicity Testing

Whole Effluent Toxicity Testing

For more detailed information on TestAmerica's Whole Effluent Toxicity testing services, please click here to download our brochure.

NPDES permit programs utilize effluent chemical monitoring and Whole Effluent Toxicity (WET) testing to determine if a treated wastewater, discharged into receiving waters, poses a potential risk of toxicity to
aquatic organisms and human health. WET tests describe the aggregate toxic effect of an effluent sample, measured by a test organism's response to exposure (e.g., lethality, impaired growth, or
reproduction). Further, the tests represent the total effect of exposure of aquatic organisms to effluent, without requiring the identification of the specific pollutants. WET testing is a key element to
implementing water quality standards through NPDES permit.

WET monitoring requirements are included in NPDES permits to determine whether a wastewater has a reasonable potential to cause acute (i.e. lethal) and/or chronic (i.e. sub-lethal effects) toxicit y in
aquatic organisms.

  • Acute toxicity is a measure of pr imarily lethal effects that occur over a short period of time (i.e. 96 hours or less).
  • Chronic toxicity refers to sub-lethal effects, such as inhibition of fertilization, growth, and reproduction hat occur over a longer exposure period (i.e. 4-7 days).

WET test methods include procedures for freshwater, marine, and estuarine test species. EPA recommends WET tests use an invertebrate (water flea), vertebrate (fathead minnow), and a plant (algae) to identify the
most sensitive species and any potential for toxicity. If WET testing demonstrates that the wastewater shows a reasonable potential for toxicity, then a WET limit must be included in the permit. WET test results are used in determining compliance with NPDES WET permit limits.

TestAmerica's Analytical Approach to WET Testing

TestAmerica’s Aquatic Toxicity laboratory staff work directly with clients to evaluate and manage WET toxicity testing requirements. For 29 years, TestAmerica staff has provided toxicity testing services and interpretation of data for our clients.  TestAmerica is NELAP certified for toxicity testing in many states throughout the nation.  

TestAmerica Corvallis, located in Corvallis, OR, offers the following acute and chronic toxicity testing options:

 

Acute Toxicity Testing

• Pimephales promelas (fathead minnow)
• Ceriodaphnia dubia (water flea)
• Cyprinodon variegatus (sheepshead minnow)
• Menidia beryllina (inland silverside)
• Atherinops affinis (topsmelt), West Coast species
• Mysidopsis bahia (mysid shrimp)
• Oncorhynchus mykiss (rainbow trout)
• Daphnia pulex or Daphnia magna (daphnid)

Chronic Toxicity Testing

• Pimephales promelas (fathead minnow)
• Ceriodaphnia dubia (water flea)
• Cyprinodon variegatus (sheepshead minnow)
• Menidia beryllina (inland silverside)
• Atherinops affinis (topsmelt)
• Mysidopsis bahia (mysid shrimp)
• Oncorhynchus mykiss (rainbow trout)
• Selenastrum capricornutum (green algae)

In addition to our standard list of WET tests, our aquatic toxicity laboratory works directly with our Treatability Research Center to perform or develop custom treatment processes to address unique client needs to reduce and or identify toxicity. These types of tests are developed through additional consultation and include treatment technologies, as well as cross-collaboration between TestAmerica Corvallis' Treatability Research Center and Aquatic Toxicity laboratories (e.g. treatment evaluations to examine toxicity reduction).  To learn more about treatability testing, please visit our Treatability Testing page.