Screening Evaluations for Upland Confined Disposal Facility Effluent Quality

摘要

Section 404 of the Clean Water Act requires evaluation of the potential impacts of dredged material discharges from confined disposal facilities (CDFs). A joint U. S. Army Corps of Engineers (USACE) and U.S. Environmental Protection Agency (EPA) Technical Framework (USACE/EPA 2004) provides guidance for evaluation of potential contaminant pathways to determine if controls or management actions are required. Guidance for implementation of the Technical Framework is provided in the USACE Upland Testing Manual (UTM) (USACE 2003). The UTM provides a tiered approach for performing pathway evaluations. Tier II of the UTM contains a screening methodology to determine the need for pathway testing. The screens compare screening criteria, such as water quality standards, with predictions based on bulk sediment chemistry and partitioning//bioavailability relationships. One potential pathway of contaminant release from CDFs is effluent water discharged during CDF filling operations. An elutriate test procedure is available to predict chemical releases in effluent for comparison to water quality criteria, and water column bioassays are available to determine potential toxicity of effluent (Palermo and Thackston 1988a, 1988b; Palermo 1985; EPA/USACE 1998; USACE 2003). This technical note provides procedures developed for Tier II of the Upland Testing Manual (USACE 2003) to conduct an initial screening evaluation of CDF effluent quality. The screening evaluation is based on equilibrium partioning principles and conservative application of design and operating principles for CDFs.