By employing a structured, tiered approach of manipulation using various physical, chemical and even biological treatments, the cause or causes of toxicity in an effluent sample are determined in a toxicity identification evaluation (TIE).  Although TIE methods were originally developed as forensic tools for use with toxic effluents, the procedures have proven invaluable in a variety of situations and discharge conditions.  TIEs can be applied in risk assessment studies to provide a more accurate list of significant stressors that are likely to cause adverse impacts to aquatic and terrestrial organisms.

The success of TIEs depends on the experience of the researcher.  Small changes in toxicity or unusual responses to manipulations can occur when certain toxicants or toxicant combinations are present.  The expertise of TRE researchers, built through the success of TIEs on many different municipal and industrial wastewaters, can make the difference between a successful and failed TIE.  This is especially true when organism response is subtle or marginal. Our staff is experienced in conducting acute and chronic Phase I, Phase II and Phase III TIEs from sources such as:

  • Municipal wastewater
  • Food processing
  • Meat packing
  • Hardrock mining
  • Oil refineries
  • Gas and oil fields
  • Chemical manufacturing

TIEs are frequently part of a larger effort referred to as a Toxicity Reduction Evaluation, or TRE. Our scientists have developed and executed Toxicity Reduction Evaluation plans for many of our clients and worked closely with design and engineering firms to integrate toxicological data with waste stream and engineering information to yield economic and environmentally sound treatment options.