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SEDIMENT TOXICITY IDENTIFCATION EVALUATION (TIE) AND THE TMDL PROCESS
Citation:
Ho, K T., R M. Burgess, M Pelletier, D E. Campbell, K T. Perez, M Cantwell, K J. Rocha, J A. Cardin, R L. Johnson, AND E W. Davey. SEDIMENT TOXICITY IDENTIFCATION EVALUATION (TIE) AND THE TMDL PROCESS. Presented at 3rd International Conference on Remediation of Contaminated Sediments, New Orleans, LA, January 24-27, 2005.
Description:
The Total Maximum Daily Loading (TMDL) process requires states in the US to assess and categorize all surface waters to meet specific use requirements (e.g., swimmable, fishable etc.). Waterbodies not meeting use criteria are listed as impaired and must be remediated. Steps to remediate impaired water bodies include identification of the stressor, assessment of stressor source, and determination of environmentally appropriate loading values. Identification of the stressor is a critical early part of the process towards remediation of a water body. Sediment Toxicity Identification Evaluations( TIEs) are a valuable tool when used in a comprehensive approach to determine stressors present and active in a system. We have developed an approach to identify pollutants within a TMDL framework which includes the use of TIEs and other diagnostic tools. This phased approach to diagnosing a stressor has been named Pollutant Identification and Evaluation (PIE). PIEs consider three major stressor groups-- nutrients, toxics and clean sediments. Phase 1 of a PIE evaluates existing data and uses a series of logical steps to determine if the initial impairment assessment is valid. The objective of Phase 2 is to determine the presence of a source, stressor and effect. Phase 3 strives to develop a logical relationship between source, stressor and effect. Finally, Phase 4 confirms the diagnosis. We are currently conducting a case study to aid us in evaluating this approach for its?diagnostic value and determine which tools used in phases 2 and 3 have the greatest diagnostic value.