Evaluation of Dredged Material Proposed for Disposal at Island, Nearshore, or Upland Confined Disposal Facilities - Testing Manual

摘要

This manual is a resource document providing technical guidance for evaluation of potential contaminant migration pathways from confined disposal facilities (CDFs). Disposal of dredged material in CDFs is one of the most commonly considered alternatives for material deemed unsuitable for conventional open water disposal because of potential contaminant impacts and is also an option commonly considered for disposal of contaminated sediments dredged for purposes of sediment remediation. If contaminated sediments are placed in a CDF, consideration of pathways for migration of contaminants from the site and potential contaminant impacts may be required. A suite of evaluation procedures and laboratory test procedures has been developed to evaluate CDF contaminant pathways and is presented in detail in this manual. A tiered testing and evaluation approach is used. The Tier I evaluation determines the need for pathway evaluations, pathways of concern, contaminants of concern, and which pathways require more detailed evaluations based on existing information. Tier II evaluations consist of determining the need for management actions derived from very conservative techniques that use the chemical, physical, and biological characteristics of the dredged material and basic information about the CDF. Tier III focuses primarily on definitive evaluations, including pathway testing. Tier IV, which should rarely be needed for navigation projects, includes formal quantitative risk assessment designed to answer specific, well- defined questions.