Abstract

 The purpose of performing a sediment quality assessment is to determine whether sediments pose a risk to aquatic organisms or humans. Once a determination is made that sediments pose a risk at a site, cleanups are often stalled at the point of determining performance measures for a remediation. Determining site-specific cleanup values is costly and can be confounded by many factors (e.g., mixtures of contaminants, local background chemical concentrations and biological conditions, water body usage, regulating agency experience and bias, as well as political considerations). Because of the complexity with determining site-specific cleanup values, many regulatory agencies are setting target cleanup levels at empirically derived sediment quality guidelines (e.g., ER-L, ER-M, TECs, PECs). Agencies often default to the more restrictive of the sediment quality guidelines (e.g., ER-L over ER-M or TEC over PEC). These numbers are often too restrictive and put the onus on the responsible party to perform costly studies to determine site-specific cleanup levels.
  At many contaminated sites, "background" chemical concentrations exceed many of the lower-effects sediment quality guidelines (e.g., TEC, ER-L). Also many contaminated sites exhibit similar biological community structures to their surrounding areas due to background chemicals and physical factors unrelated to a particular source that are not conducive to abundant, diverse benthic communities. These factors along with the difficulty of determining site-specific values can be used to accelerate the cleanup process by setting non-numeric, performance-based cleanup targets. This is particularly true for small sites situated within areas that have "background" levels of contaminants or physical factors that impair the aquatic community.
Conditions that are more conducive to negotiation of performance based cleanup standards include smaller projects (e.g., <10,000 cubic yards), a cooperative approach with regulators, community involvement, and desire to redevelop bordering property with waterfront as a complimentary amenity.