Washington State Department of Ecology

Publication Summary

Title

Control of Toxic Chemicals in Puget Sound: Evaluation of Loading of Toxic Chemicals to Puget Sound by Direct Groundwater Discharge

Month-Year Published

April 2011

Online Availability

View this publication in Acrobat PDF format

1317 kilobytes, requires version 4.0 or later of Adobe Acrobat Reader Software get Acrobat Reader

Short Description

This study presents estimates of the annual chemical mass delivered to Puget Sound by direct (submarine) groundwater discharge, for 34 toxic chemicals of concern. The report (1) describes the methods and assumptions used to develop the loading estimates and (2) discusses sources of uncertainty in the values. The loading estimates best represent an upper-bound (worst-case) condition; actual toxic loading to Puget Sound by direct groundwater discharge is likely significantly lower than the estimates presented.

The groundwater loading estimates will be synthesized with loading estimates for other toxic delivery pathways during Phase 3 of the Control of Toxic Chemicals in Puget Sound project.

(Also see abstract below)

Publication Number

11-03-023

Author(s)

Pitz, C.

Print Availability

Request from the program.

Number of pages

Keywords

basin, discharge, groundwater, loading, model, Puget Sound, toxic chemicals

Subject Waterbodies

Skagit Bay, Similk Bay, Port Susan, Possession Sound, Tacoma Narrows, Case Inlet, Dana Passage, Hood Canal, Admiralty Inlet, Rosario Strait, Puget Sound, Great Bend, Lynch Cove, Dalco Passage, Poverty Bay, Nisqually Reach, Drayton Passage, Balch, Cormorant passages

Related Publications

Title

Relationship

Quality Assurance Project Plan: Puget Sound Groundwater Toxics Loading Analysis, Direct Discharge Pathway

supporting publication

Appendix A: Shoreline Classification Analysis Results

appendix

Appendix B: Groundwater Discharge Analysis Results

appendix

Appendix C: COC Concentration and Mass Flux Estimates - Non-detect substitution Method 1 (0.5RL)

appendix

Appendix D: COC Concentration and Mass Flux Estimates - Non-detect substitution Method 2 (Lowest RL)

appendix

Appendix E: COC Concentration Decision - Ambient Areas

appendix

Abstract

Long Description

In 2010-2011, the Washington State Department of Ecology developed quantitative estimates of the annual toxic chemical load delivered to Puget Sound by direct groundwater discharge. The analysis was performed for a priority list of 34 toxic chemicals of concern identified during Phase 1 of the Control of Toxic Chemicals in Puget Sound project. The results of this evaluation will help to:

Estimate the maximum annual toxic chemical load likely to be delivered to Puget Sound via direct discharge of groundwater.

Improve understanding of the relative contribution of the direct groundwater discharge pathway in comparison to other toxic loading pathway estimates.

Provide data to support refinements to Ecology′s Puget Sound Toxics Box Model.

The report (1) describes the methods and assumptions used to develop the loading estimates and (2) discusses sources of uncertainty in the predictions. The loading values presented in the report best represent an upper-bound (worst-case) condition. Actual toxic loading to Puget Sound by direct groundwater discharge is likely significantly lower than the estimates presented.

In Phase 3 of the Control of Toxic Chemicals in Puget Sound project, the groundwater loading estimates presented in this report will be synthesized with loading estimates for other toxic delivery pathways. This information will support ongoing efforts to improve the accuracy of the overall Puget Sound Basin toxics budget.

This page last updated August 17, 2011