Whole Effluent Toxicity Testing & TIE/TRE Services for Compliance
Persistent toxicity in wastewater effluents can place your operations at risk of exceeding Whole Effluent Toxicity (WET) limits in an NPDES permit—resulting in potential penalties, project delays, or reputational damage. At EnviroScience, we help facilities across a wide range of industries identify, resolve, and prevent effluent toxicity issues through expert Toxicity Identification Evaluations (TIEs) and Toxicity Reduction Evaluations (TREs).
What Is a TIE/TRE Evaluation?
A Toxicity Identification Evaluation (TIE) is a structured, EPA-approved methodology used to determine the specific toxicants responsible for observed toxicity in effluents. Once the suspected source of toxicity is known, a Toxicity Reduction Evaluation (TRE) implements corrective actions to mitigate or eliminate these toxicants—ensuring regulatory compliance and long-term environmental sustainability.
Why Whole Effluent Toxicity Compliance Matters
WET testing is a key requirement under the Clean Water Act and NPDES permitting. Regulatory agencies may mandate a TIE/TRE investigation to restore compliance when toxicity is detected in effluent discharges. Without timely resolution, your organization may face:
- Expensive enforcement actions
- Delays in permit renewals
- Project shutdowns or discharge limitations
- Negative community or public perception
EnviroScience’s Proven TIE/TRE Process
With over 35 years of regulatory and laboratory experience, EnviroScience provides a full-service, stepwise TIE/TRE approach designed to address compliance targets and reduce operational disruptions efficiently.
Our process includes:
✅ Adherence to EPA toxicity testing protocols
✅ Establishing baseline toxicity through in-house WET testing
✅ Site-specific evaluations of plant operations, chemical usage, and treatment processes
✅ Data-driven recommendations to eliminate toxicity at the source
✅ Ongoing technical support throughout regulatory interactions
Customized Toxicity Solutions for Your Industry
Our TIE/TRE services are tailored to the needs of:
- Municipal wastewater treatment plants
- Industrial and manufacturing facilities
- Chemical processors
- Power generation stations
- Mining and extraction operations
No matter your industry, we help you meet your discharge permit requirements and minimize the risk of costly fines or shutdowns.
Case Study: How We Helped a Client Avoid Six-Figure Penalties
One industrial facility faced recurring toxicity exceedances that jeopardized its permit renewal. Within 90 days of initiating a TIE/TRE with EnviroScience, we identified the key contributors to effluent toxicity and recommended targeted process adjustments.
The result: complete elimination of exceedances and regulatory approval—without costly plant upgrades.
FAQs: TIE/TRE and Whole Effluent Toxicity Testing
Q: What is the difference between a TIE and a TRE?
A: TIE identifies the suspected toxicants responsible for noncompliance. A TRE follows up by applying and evaluating corrective actions to reduce or eliminate that toxicity.
Q: Why would my facility need a TIE or TRE?
A: If your discharge fails a WET test or shows persistent toxicity in bioassay results, regulators may require a TIE/TRE to investigate and correct the issue.
Q: How long does the TIE/TRE process take?
A: The timeline varies, but most initial TIE evaluations and recommendations are completed within a few weeks. Ongoing support is provided as necessary during the implementation of the TRE corrective action.
Q: What regulations require TIE/TRE testing?
A: EPA and state agencies require TIE/TRE under the Clean Water Act when WET testing indicates recurring or unexplained toxicity in effluent discharges.
Get Ahead of Compliance Issues—Contact EnviroScience Today
Don’t wait for a permit violation to take action. EnviroScience’s expert Laboratory Services team, led by Director of Laboratory Services Jennifer Vydra, is ready to help you navigate your TIE/TRE needs with confidence and precision.
Few environmental firms in the country retain EnviroScience’s degree of scientific know-how, talent, and capability under one roof. The diverse backgrounds of our biologists, environmental engineers, scientists, and divers enable us to provide comprehensive in-house services and an integrated approach to solving environmental challenges—saving clients time, reducing costs, and ensuring high-quality results.
Our client guarantee is to provide “Excellence in Any Environment,” meaning no matter what we do, we will deliver on our Core Values of respect, client advocacy, quality work, accountability, teamwork, and safety. EnviroScience was created with the concept that we could solve complex problems by empowering great people. This concept still holds true today as our scientists explore the latest environmental legislation and regulations and incorporate the most up-to-date technology to gather and report data.
EnviroScience expertise includes but is not limited to aquatic surveys (including macroinvertebrate surveys and biological assessments); ecological restoration; ecological services (including impact assessments, invasive species control, and water quality monitoring); emergency response; engineering and compliance services; endangered mussel surveys; laboratory and analysis; stormwater management; sustainability services; threatened and endangered species; and wetlands and streams (including delineation and mitigation). Further, EnviroScience is one of the few biological firms in the country that is a general member of the Association of Diving Contractors International (ADCI) and offers full-service commercial diving services.