Event Title

Lessons from 29 years of monitoring at the Commencement Bay disposal site

Presentation Abstract

Dredged material disposal in Puget Sound is managed by the Dredged Material Management Program (DMMP), an interagency partnership consisting of the Washington State Department of Natural Resources (DNR), the U.S. Army Corps of Engineers, Seattle District (USACE), the Washington State Department of Ecology (Ecology), and the U.S. Environmental Protection Agency, Region 10 (U.S. EPA). The Commencement Bay non-dispersive aquatic dredged material disposal site in Tacoma, WA, was established in June 1988 by the Puget Sound Dredged Disposal Analysis (PSDDA) program (predecessor of the DMMP), under the dredged material management plan for central Puget Sound sites. The DMMP developed a monitoring framework to assess the physical, chemical, and biological effects of dredged material disposal at Puget Sound non-dispersive aquatic disposal sites and their surrounding environments. In the 29 years since the Commencement Bay disposal site was established, over 8.6 million cubic yards of dredged material has been taken to the site, and the DMMP has conducted 10 environmental monitoring studies to ensure compliance with the Clean Water Act and to verify that the disposal site was performing as designed. This presentation reviews the monitoring findings at Commencement Bay within the context of the DMMP framework, and explores how the program has adapted over time. As an additional performance evaluation of the disposal site, we have calculated volume weighted mean (VWM) chemical concentrations of dredged material taken to Commencement Bay using disposal volumes and pre-dredging chemistry results to determine how they compare to measurements at the disposal site during corresponding site monitoring events. As the Commencement Bay site moves into its 30th year of operation, the DMMP is evaluating the lessons learned at the site to inform potential refinements to the overall monitoring framework.

Session Title

Posters: Monitoring: Species & Habitats

Conference Track

SSE18: Posters

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE18-96

Start Date

5-4-2018 11:30 AM

End Date

5-4-2018 1:30 PM

Type of Presentation

Poster

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

This document is currently not available here.

Share

COinS
 
Apr 5th, 11:30 AM Apr 5th, 1:30 PM

Lessons from 29 years of monitoring at the Commencement Bay disposal site

Dredged material disposal in Puget Sound is managed by the Dredged Material Management Program (DMMP), an interagency partnership consisting of the Washington State Department of Natural Resources (DNR), the U.S. Army Corps of Engineers, Seattle District (USACE), the Washington State Department of Ecology (Ecology), and the U.S. Environmental Protection Agency, Region 10 (U.S. EPA). The Commencement Bay non-dispersive aquatic dredged material disposal site in Tacoma, WA, was established in June 1988 by the Puget Sound Dredged Disposal Analysis (PSDDA) program (predecessor of the DMMP), under the dredged material management plan for central Puget Sound sites. The DMMP developed a monitoring framework to assess the physical, chemical, and biological effects of dredged material disposal at Puget Sound non-dispersive aquatic disposal sites and their surrounding environments. In the 29 years since the Commencement Bay disposal site was established, over 8.6 million cubic yards of dredged material has been taken to the site, and the DMMP has conducted 10 environmental monitoring studies to ensure compliance with the Clean Water Act and to verify that the disposal site was performing as designed. This presentation reviews the monitoring findings at Commencement Bay within the context of the DMMP framework, and explores how the program has adapted over time. As an additional performance evaluation of the disposal site, we have calculated volume weighted mean (VWM) chemical concentrations of dredged material taken to Commencement Bay using disposal volumes and pre-dredging chemistry results to determine how they compare to measurements at the disposal site during corresponding site monitoring events. As the Commencement Bay site moves into its 30th year of operation, the DMMP is evaluating the lessons learned at the site to inform potential refinements to the overall monitoring framework.