Publication Summary

This is the study plan for Using Sediment Profile Imaging (SPI) to Evaluate Sediment Quality at Two Puget Sound Cleanup Sites: Part II: Port Gamble Bay.

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 with reasonable accuracy at least some of the commonly measured sediment quality triad data. These data include contaminant chemistry, laboratory toxicity, and direct evidence of benthic community impairment. If this proves to be true for at least some types of benthic habitats or sediment samples, then a preliminary SPI survey might reduce the need for, scope, and 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 in Port Gamble 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 Port Gamble Bay site. The preliminary SPI survey will be conducted from August 22-24, 2006. Ecology will conduct its follow-up sediment quality survey from August 28-30, 2006.

The final report, targeted for completion in April 2007, will describe any relationships that exist between the SPI data and triad indicators of benthic community impairment for the Port Gamble 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 SPI_PG06