A Toxicity Reduction Evaluation (TRE) is a site-specific study to identify the causes of effluent toxicity, isolate the sources of toxicity, evaluate the effectiveness of toxicity control options, and then confirm the reduction in effluent toxicity. A Discharger undergoing a TRE must choose a consultant that has:  (1) the experience with the design of the study, (2) familiarity with a multitude of discharger specific situations and (3) the technical expertise in the areas of toxicology and chemistry. 

If you are required to perform a TRE, let BMI show you how the design and implementation of a tailored plan will save you money while answering specific regulatory concerns.

Permit Negotiation – BMI has been interacting with regulatory agencies on behalf of public and private clients for permit evaluations, modifications and negotiations. Regulatory agencies make many assumptions to establish NPDES permit limits. These assumptions reflect many variables such as: 

• the characteristics of the Mixing Zone
• the identification of Resident Species 
• the effects of upstream discharges on receiving water quality

If permit limits cannot be met based on these assumptions, actual data, not assumed values, may be necessary to obtain reasonable permit limits. A permittee may desire to negotiate the renewal of a permit with actual data values. Since the generation of actual data points to establish permit limits requires time, contact BMI to determine your potential needs today.

Chemical Translator Studies – By regulation, the permit limit of metals, in most instances, must be expressed as total (recoverable) metals. This number reflects both dissolved and adsorbed or particulate forms of metal. It is the dissolved metals fraction that poses a potential toxicity risk to aquatic organisms, therefore, a translator must be used to determine the acceptable permit level of total metals that can be discharged into the receiving water.  

BMI conducts Chemical Translator studies and advises clients on the best methods for developing a site specific water quality criteria in order to gain permit relief. This includes the use of Resident Species when the Indicator Species used to develop the limits is not native to the habitat and Recalculation of the permit limits based on the study.