US Army Corps of Engineers
Seattle District Website

DMMP User Manual

The DMMP User Manual provides detailed information on current procedures for evaluating proposed dredged material for open-water disposal, as well as provides information on disposal sites and beneficial uses of dredged material.  The User Manual is periodically updated to reflect program changes made through the SMARM process.



Contact the DMMO

Seattle District (CENWS)
Dredged Material Management Office
PO Box 3755
Seattle, WA 98124-3755


2018 DMMP User Manual

The procedures in the 2018 Dredged Material Evaluation and Disposal Procedures User Manual replace guidance in all previous versions of the DMMP User Manual. The updates apply to all projects in Puget Sound, on the Washington Coast, the north side of the Columbia River, and all other water bodies within the State of Washington.

This edition of the DMMP User Manual reflects technical and policy updates that have occurred through the sediment management annual review meeting process and public workshops. It is considered to be a living document and is revised periodically as needed to reflect changes made through the public review process.  For the first time we have included an Appendix listing the major updates in this version of the User Manual.

To download the User Manual click the link or image below.


Seattle District has developed statistical analysis software called BioStat to facilitate bioassay statistical comparisons with appropriate reference sediments. Submittal of screen shots or statistical reports from BioStat will provide the documentation necessary to support summarized interpretations of bioassay data in the sediment characterization report.

To download a .zip file with all the files necessary to run BioStat, click here

DMMP Project-Specific Issue Resolution Process

In 2016, the Washington State Legislature passed a proviso directing the Washington State Departments of Ecology (Ecology) and Natural Resources (DNR) to conduct a management review of the Dredged Material Management Program (DMMP). Ecology and DNR completed their review later that year and submitted a report to the Legislature entitled “Management Review of the Dredged Material Management Program”.  The report made a number of recommendations, including:

“Define a process in the User Manual that an applicant can use to elevate an individual project decision before the management of all four DMMP agencies. The process would include a threshold for elevating an issue, a process for resolving the issue, and a timeframe in which an applicant can expect a timely response.”

DMMP agency managers and staff developed an elevation process in the fall of 2018.  This process was presented at the 2019 SMARM.  No comments were received, and the project-specific issue resolution process detailed below is now accepted and available for project proponents to use.  Detailed information is available in the link below and will be added to the next User Manual update.