R2 AM Contaminated Harbor and River Sediment
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in Ballroom 2

(BAY-1117-850689) Development of California marine sediment quality objectives using a mulitiple line of evidence framework.

Bay, S¹, Beegan, C², Vidal, D¹, Ranasinghe, J¹, Connor, M³, Greenfield, B³, Weisberg, S¹, ¹ Southern California Coastal Water Research Project, Westminster, CA, USA² California State Water Resources Control Board, Sacramento, CA, USA³ San Francisco Estuary Institute, San Francisco, CA, USA

ABSTRACT- Few states have adopted a regulatory policy for sediment quality management that includes numeric values for sediment contamination. Uncertainty and debate regarding the efficacy and reliability of chemistry-based sediment quality criteria have generally resulted in the establishment of nonregulatory guidance that places the burden on local regulators to determine how to interpret sediment quality data. California is developing a sediment quality objectives policy for bays and estuaries using a novel approach that is based on a multiple line of evidence assessment (MLOE) framework. This approach is a significant departure from other programs in several respects: 1) the sediment quality triad of chemistry, toxicity, and benthic community health is formally incorporated into policy; 2) new and refined benthic community indices specific to California habitats have been developed, 3) numeric thresholds for each line of evidence were developed using a regional database; and 4) a MLOE assessment framework has been developed that provides both a definitive conclusion regarding sediment quality and an ordinal classification useful for prioritizing impacted sites. Similar MLOE assessment frameworks were also developed for assessing sediment contamination relative to impacts on human health and wildlife, but additional data are needed to address site-specific issues related to variations in prey species, wildlife receptors, and fish consumption rates.

Key words: sediment, assessment, sediment quality triad, california