Aquatic Toxicology

What is aquatic toxicology / toxicity?

Aquatic Toxicology is an analysis which studies the adverse effects of chemicals on aquatic organisms. These organisms are subjected to varying concentrations of an aqueous solution to determine if lethal or sub-lethal effects are observed. Bioassay tests can also be applied to soil and sediment materials with plant and terrestrial invertebrate species.

What is Whole Effluent Toxicity (WET) testing?

NPDES permit programs utilize effluent chemical monitoring and Whole Effluent Toxicity (WET) testing to determine if an effluent (treated wastewater / stormwater / other process waters) 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) toxicity in aquatic organisms. Other options include: hazardous waste designation testing, pure product testing, sediment/soil toxicity testing.

Acute Toxicity

Acute toxicity is a measure of primarily lethal or immobilization effects that occur over a short period of time (i.e. 96 hours or less).

• 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

Chronic toxicity refers to sub-lethal effects, such as inhibition of fertilization, growth, and reproduction that occur over a longer exposure period (i.e. 4-7 days).

• 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)

WET test methods include procedures for freshwater, marine, and estuarine test species. EPA recommends WET tests use an invertebrate, vertebrate (fish), and a plant 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.

How can Eurofins support aquatic toxicology testing?

Eurofins is a NELAC-accredited laboratory with the ability to add additional certifications as needed. Our National Pollutant Discharge Elimination System (NPDES) / toxicity compliance experience spans a broad range of contaminants and aquatic environments (e.g., freshwater, estuarine, lake, stream, wetland, and tidal). The staff performs thousands of toxicity tests ranging from simple acute testing to lifecycle chronic and bioaccumulation studies. This experience includes testing over 40 different marine and freshwater vertebrate, invertebrate, algal, and plant species. Representative services include:

We offer a broad range of aquatic toxicology testing including the design of client-specific test protocols required to satisfy Clean Water Act (CWA) specifications and other non-wastewater needs. Our testing capabilities include:

• Toxicity Reduction Evaluations (TREs)
• Toxicity Identification Evaluations (TIEs)
• Whole Effluent Toxicity (WET) Tests
• Toxicity Treatability Evaluations (TTEs)
• Water Quality Based Effluent Limits (WQBELs)
• Bioassay Testing and Chemical Analyses
• Criteria Development
• Permit Reviews and Evaluations
• Evaluation of Uncontrolled Releases

All of our aquatic toxicology tests are performed in accordance with USEPA methods. If required, customized protocols are employed for non-wastewater sources to comply with other regulatory agency requirements. Our culture laboratory consists of systems designed for the purpose of breeding healthy organisms with genetic traceability. Monthly Standard Reference Toxicant (SRT) tests are performed on all organisms cultured in house. Concurrent SRT tests are performed on organisms brought in from outside culture laboratories. All SRT data is graphed and evaluated for consistency.

Specialty Services

In addition to providing standard analytical testing to support environmental remediation projects, pilot testing, and routine monitoring, the laboratory provides specialty testing for the following:

• PFAS water treatment studies
• Pore water generation
• Nonaqueous phase liquid (NAPL) mobility and hydrocarbon identification
• Geotechnical characterization of soils (sieve analysis, grain size, bulk density, etc.)