Water Quality Improvement Project
Sinclair/Dyes Inlets Water Quality Improvement Project


WA Department of Ecology is working with Puget Sound Naval Shipyard and the U.S. Environmental Protection Agency under a partnership called ENVVEST (short for “Environmental Investment”) to address water quality problems in Sinclair and Dyes Inlets.

Water quality issues

Sinclair Inlet and Dyes Inlet were listed on the 1998 303(d) list of impaired waters because of fecal coliform contamination in the marine waters and metals and other contaminants in bottom sediments. In addition, a number of creeks that discharge to these inlets were listed for fecal coliform contamination. To address all the contamination issues using a watershed approach, a partnership was established between Department of Ecology as the state agency that establishes TMDLs (Water Cleanup Plans), the Puget Sound Naval Shipyard, and U.S. Environmental Protection Agency working together on Project ENVVEST (an acronym for ENVironmental InVESTment).

The three agencies agreed to tackle fecal coliform bacteria as the initial water quality problem that required a Water Cleanup Plan. Through the use of models that take into account the dynamic nature of the marine inlets and the multiple sources of fecal coliform bacteria from the surrounding watershed, the project will provide regulators with a determination of the inputs that represent the major sources of fecal coliform bacteria and enable them to develop a plan for reducing these inputs.

The study area for the Sinclair/Dyes Inlets fecal coliform Water Cleanup Plan includes the marine waters of Sinclair and Dyes Inlets and their surrounding watersheds (see study area map). Land uses in the watershed include urban, suburban, rural residential, small hobby farms and some undeveloped land. Based on these land uses, the major sources of fecal coliform bacteria are expected to be:

Puget Sound Naval Shipyard & Intermediate Maintenance Facility in Bremerton developed an integrated model to assess fate and transport of bacteria to marine waters.
  • Human sources
    • Stormwater, when heavy rainfall causes overflows of untreated sewage in combined sewer – stormwater facilities
    • Leaks in the sanitary sewer system
    • Illegal sanitary connections to storm drains
    • Failing septic systems or poorly operated package systems
    • Landfills
  • Non-human sources
    • Urban areas: Pets and urban wildlife (rats, raccoons, pigeons, gulls)
    • Rural areas: Cattle, horses, poultry and wildlife (beaver, deer, waterfowl)

Status of the project

July 5, 2012

On April 17, 2012 Ecology submitted the finalized water quality improvement report to EPA for approval. EPA approved the report on July 5, 2012.

August 4, 2011

Once Ecology responds to comments received, we will send the finalized water quality improvement report and implementation plan to EPA for approval.

June 24, 2011: Draft TMDL available for public review and comment

Ecology invited public comment on the study and plan, which is titled “ Sinclair and Dyes Inlets Fecal Coliform Bacteria Total Maximum Daily Load: TMDL and Water Quality Implementation Plan” through August 1, 2011. Ecology also hosted two public meetings on the TMDL: July 20 and 21, 2011. Ecology and other officials were available to answer questions.

February 17, 2011 TMDL Local Review Meeting

Update on the Bacteria Study

Fall 2004 and 2005

Complete the stormwater sampling for Sinclair and Dyes Inlets. Stormwater sampling involves a great deal of weather report watching and tight coordination among the project managers, sampling teams, and Ecology’s Manchester Laboratory, which analyzes the samples. Two more storm events will be sampled in fall 2004. The full storm data set will include both quantity and quality of the stormwater. These data will be of both regional and national interest because very few studies across the nation have measured the flow (quantity) of stormwater, in addition to quality, through a storm event.

Complete the testing of the two models – the freshwater model that takes rainfall, runs it over the pervious and impervious land surfaces of the Sinclair and Dyes watersheds, and calculates resulting stream and stormwater flow into the two inlets—and the marine model that receives the flow and fecal coliform outputs of the freshwater model, takes into account tides, time of year and other factors, and calculates fecal coliform concentrations over all parts of the two inlets.

2005 - Once the models are run and the results indicate the most important freshwater sources of bacteria to the marine waters, Ecology will work with implementing agencies, PSNS, Tribes, watershed groups and citizens to develop a plan for eliminating these sources. Already, Ecology has provided grant funding to Kitsap County Health District for projects to locate and fix sources of bacteria – including failing septic systems and potential livestock sources – in several creeks in the Dyes Inlet watershed.

November 2003

Washington Department of Health reopened a large portion of northern Dyes Inlet for shellfish harvest. Approximately 1500 acres were reclassified from prohibited to conditionally approved. This meant that oysters, clams and other shellfish grown in these waters are now available for direct harvest, although temporary closures will still be needed when any sewage is discharged to the Port Washington Narrows.

Working with the Department of Health to accomplish this change were local citizens, City of Bremerton, Kitsap County Health District, Suquamish Tribe, Washington Department of Health, and U.S. Navy Puget Sound Naval Shipyard and Intermediate Maintenance Facility (PSNS). An important element assisting the Department of Health decision was the use of the Navy’s dynamic model of the inlets to demonstrate the geographic distribution of bacteria from combined sewer overflows under different storm and tidal conditions.

Storm, wet and dry season sampling – 2002 and 2003

Representing high quality science and leadership by PSNS and excellent cooperation among local partners involved in this project was the 2002-2003 water quality sampling program. Both wet season (winter) and dry season samples were collected, and in addition, storm event sampling was conducted to assess bacterial inputs during periods of high discharge from creeks and stormwater outfalls. Marine samples were taken concurrently to develop fecal coliform datasets for the whole watershed. By combining bacterial concentration data for each creek or outfall with its discharge rate during the event, the loading of bacteria from these sources to the marine waters can be calculated. The relative amount of loading from different sources will be useful in determining priorities for corrective actions in the Water Cleanup Plan. The load quantities will be used to calculate how much reduction is needed from each source, in order for marine waters and creeks to meet water quality standards.

Why this matters

Fecal coliform is a type of “bacteria” common in human and animal waste. It can make people sick and cause the closure of shellfish harvesting beds. Bacteria can get into our waters from untreated or partially treated discharges from wastewater treatment plants, from improperly functioning septic systems, and from livestock, pets and wildlife.

People can help keep bacteria out of the water. Properly collect, bag, and trash dog poop. Check your on-site sewage system to make sure it is maintained and working properly.

Technical information

Unless otherwise specified, the following documents are Ecology publications.

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Last updated August 2016


WRIA: #15 (Kitsap)
County: Kitsap

Water-body Names:
Mosher, Pahrmann, Barker, Clear, Strawberry, Chico, and Oyster Bay creeks draining to Dyes Inlet
Wright, Gorst, Anderson, Ross, Blackjack, Annapolis, Karcher, and Sacco creeks draining to Sinclair Inlet
Enetai, Springbrook, Illahee, and Wautaga creeks draining to Port Orchard Passage
Beaver Creek draining to Rich Passage (Clam Bay). Phinney Creek

Fecal coliform bacteria

# of TMDLs: 22

TMDL Approved by EPA
Has an implementation plan

Contact Info:
Danielle DeVoe
Phone: 425-649-7036
Email: Danielle.DeVoe@ecy.wa.gov

Northwest Region
Department of Ecology
3190 - 160th Ave. SE
Bellevue, WA 98008-5452