Publication Summary

This is the study plan for Using Sediment Profile Imaging (SPI) to Evaluate Sediment Quality at Two Puget Sound Cleanup Sites: Part I - Lower Duwamish Waterway.

The Washington Department of Ecology (Ecology) is evaluating the use of preliminary Sediment Profile Imaging (SPI) surveys to streamline studies of contaminated sediment cleanup sites. This may be feasible if SPI data, such as the Redox Potential Discontinuity depth or Organism Sediment Index, can predict at least some of the commonly measured sediment quality triad data. These data include contaminant chemistry, laboratory toxicity, or direct evidence of benthic community impairment. If SPI data can predict at least some types of benthic habitats or sediment samples, then a preliminary SPI survey might reduce the need for, the scope, and the cost of more detailed cleanup site investigations.

The SPI Feasibility Study involves two sites. The Lower Duwamish Waterway in Seattle has surface sediments containing mixtures of chemical contaminants, including PCBs, phthalates, trace metals, and polycyclic aromatic hydrocarbons. In contrast, the former Pope and Talbot mill site on Port Gamble Bay contains few of the contaminants found elsewhere in Puget Sound but does have large areas of wood waste that can alter benthic communities.

This Quality Assurance Project Plan describes the project that will be conducted at the Lower Duwamish Waterway site. The preliminary SPI survey will be conducted from July 23-25, 2006. Ecology will conduct its follow-up sediment quality survey from August 8-11, 2006.

The focus of the final report, targeted for completion in April 2007, will be to describe any relationships that exist between the SPI data and triad indicators of benthic community impairment for this site. In addition, some sample data may serve to fill data gaps, confirm earlier results, or provide a baseline for post-cleanup monitoring.

Link to EIM data for User Study ID SPILDW06