PT15 Contaminated Harbour and River Sediment
Exhibit Hall
8:00 AM - Tuesday
(PT248) Development of a Multiple Endpoint Weight-of-Evidence Ecological Assessment Methodology.
Mitchell, D1, Bleiler, J. 1, Davis, R.2, Finkelstein, K.3, Keckler, K.4, Munney, K.5, Angus, T.6, Durrett, C.6, 1 ENSR International, Westford, MA, USA2 U.S. Army Corps of Engineers, Concord, MA, USA3 National Oceanic and Atmospheric Administration, Boston, MA, USA4 U.S. Environmental Protection Agency, Boston, MA, USA5 U.S. Fish and Wildlife Service, Concord, MA, USA6 Massachusetts Department of Environmental Protection, Boston, MA, USA
ABSTRACT- A multiple endpoint weight-of-evidence (WOE) risk assessment tool was developed to help support an investigation of an urban riverine system in southern New England. The WOE approach uses both qualitative and semi-quantitative protocols to evaluate and interpret the results from nine measurement endpoints. The protocol was developed collaboratively by the project team, which was comprised of the potentially responsible party, state and federal agencies, natural resource trustees, and the public. In order to avoid bias in application of the methodology, the protocols for WOE risk analysis were decided upon before review of any site-specific data. The initial step was to reach consensus regarding the weight accorded each of the measurement endpoints. The second step in the protocol development was to establish the sampling location-specific measurement endpoint decision rules. These rules establish whether the results of specific measurement endpoints suggest a potential for ecological risks. A second set of semi-quantitative decision rules was developed to permit the risk assessor to evaluate the sampling location-specific data within the context of the broader riverine sampling reaches under investigation in this program. The relative potential for risks in the overall riverine system (i.e., across reaches) was evaluated through the use of several methodologies, including development of a relative risk ranking system for each assessment endpoint. This ranking system considered the relative weight, as well as the risk potential, of each measurement endpoint at each sampling station. Although the absolute numerical values generated from the relative risk ranking are unitless and may not be ecologically meaningful as a stand-alone metric, this relative ranking helped to identify those sampling locations and sampling reaches that contribute disproportionately to the relative risk. Evaluation of these results will enable risk managers to determine the potential for ecological risks in different sampling reaches and sampling locations relative to one-another.
Key words: ecological risk assessment, sediment, weight-of-evidence