Computerization of the Decision-Making Framework: Surface Runoff Toxicity Bioassay Test Results (LAT-R Program)
Abstract
The Decision-Making Framework (DMF) for the management of dredged material has been developed and used at numerous Corps projects (Lee and others 1991). Among the many components of the DMF is surface runoff water quality, which is one of the pathways investigated when confined disposal is considered. Evaluation of surface runoff quality, like the evaluation of effluent quality, is based on the chemical composition of the discharge as well as the biological effects (toxicity). To perform these evaluations, surface runoff tests (Skogerboe, Price, and Brandon 1988) are performed on wet, anaerobic sediment and oxidized, aerobic sediment to generate representative samples of the runoff immediately after disposal and later when the dredged material has dried out. The chemical composition of the runoff test samples is compared with existing water quality standards. When constituents not having water quality standards are present or a biological evaluation is desired, the toxicity of the surface runoff test samples is evaluated using the water column bioassay test for acute toxicity (U.S. Environmental Protection Agency/U.S. Army Corps of Engineers (USEPA/USACE) 1994). Analysis of these test results has now been computerized as part of the Automated Dredging and Disposal Alternatives Modeling System (ADDAMS) (Schroeder and Palermo 1995). The surface runoff test for chemical composition is evaluated using the RUNQUAL module (Schroeder, Gibson, and Dardeau 1995), and the bioassay test is analyzed by the LAT-R module (Laboratory Analysis of Toxicity from a CDF Runoff), which is described herein. The LAT-R program compares survival data for various aquatic organisms at several runoff dilutions and computes the LC50 for the runoff under both wet and dried conditions. Using the LC50 and a mixing zone model, the toxicity of the discharge can be evaluated for compliance with water quality regulations. The purpose of this technical note is to introduce the LAT-R module.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1997
- Accession Number
- ADA381011