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Water Quality Improvement Projects (TMDLs)

Water resource inventory area (WRIA) 14, Washington State.

Water Quality Improvement Projects
Oakland Bay Area Projects


Oakland Bay is typical of the narrow, shallow embayments characterizing South Puget Sound in Washington State. While they are highly productive areas for shellfish and salmonids, low flushing rates also make these areas very sensitive to human impacts. For over 100 years Oakland Bay’s protected waters have made it an ideal port for the city of Shelton, whose economy is based upon the lumber and pulp mills dominating the waterfront. Shelton operates a domestic wastewater treatment plant that discharges treated sewage into Oakland Bay near Eagle Point.

Oakland Bay is one of the most important commercial shellfish areas in the country, producing over three million pounds of manila clams a year. Other shellfish produced in this area include Kumamoto and Pacific oysters, and mussels. The shellfish industry is a critical economic factor to the local economy. Oakland Bay has numerous commercial shellfish growers registered with the Washington State Department of Health. There are hundreds of recreational harvesting areas on state-owned tidelands and it is an important harvest area for the Squaxin Island Tribe.

Land use is primarily commercial forest, with a much smaller percentage dedicated to residential development and agriculture. Shorelines of both the marine area and the lakes in the watershed are heavily developed. Agricultural lands are dominated by small hobby farms.

Oakland Bay from Public Fishing Beach.  Photo courtesy of Anise Ahmed, WA Dept. of Ecology.

Water quality issues

Areas in Oakland Bay fail to meet state water quality standards for fecal coliform bacteria. In many marine waters, water quality standards for bacteria are set to protect shellfish harvest. Protecting the significant commercial and tribal shellfish harvest in Oakland Bay was an important consideration in beginning this water cleanup process.

Several tributaries to Oakland Bay and Hammersley Inlet also have bacteria problems. In freshwater, too much bacteria can pose a health risk to people swimming, fishing, or playing in the water. 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. Contaminated tributaries also contribute to bacteria concentrations in Oakland Bay and Hammersley Inlet. Reductions in bacteria concentrations are needed in Campbell, Cranberry, Deer, Uncle John, Malaney, Shelton, Johns, Mill, and Goldsborough Creeks.


Protecting the significant commercial and tribal shellfish harvest in Oakland Bay was an important consideration in beginning this water cleanup process. To protect shellfish harvest, salmon, and recreational use of area water bodies, Ecology and local partners began a cleanup process in the spring of 2003. The first step of the process was a water quality study. Starting with an evaluation of existing water quality data, Ecology and the technical advisory group designed a study plan to fill information gaps. After completion of the plan for the bacteria study, called the Quality Assurance Project Plan (QAPP), field work for the study began in fall 2004. The Squaxin Island Tribe conducted most of the field work for the temperature study. Field work for the studies was conducted throughout 2005. During 2006-07 the data was compiled, analyzed, and modeled.

Ecology released and made available the bacteria study report and summary cleanup plan (more commonly referred to as the total maximum daily load, or TMDL) for public review and comment May 9 - June 8, 2011. After addressing comments, Ecology submitted the report to the federal Environmental Protection Agency (EPA) for consideration on June 30, 2011. The EPA approved the TMDL on August 18, 2011. Included in the TMDL were implementation plan specifics. The EPA does not approve those sections of the TMDL.

Now that EPA has approved the bacteria report, Mason County's Action Plan provides the foundation for cleanup plans. Cleanup work includes continued monitoring, evaluation, and adjustment of cleanup strategies to achieve bacteria reduction targets.

Project information

Cranberry, John, and Mills Creeks

Oakland Bay and Hammersley Inlet

Related information

Oakland Bay Study: A dye and modeling study in an enclosed estuary with a high degree of refluxing (Ecology Publication)
Report on a dye study, commissioned by the City of Shelton, of their wastewater discharge near a shellfish closure zone in Oakland Bay and Hammersley Inlet.

Reconnaissance Survey of Inner Shelton Harbor Sediments: Chemical Screening of Nearshore Sites and Evaluation of Wood Waste Distribution (Ecology Publication)
A screening level survey of sediment quality in inner Shelton Harbor, conducted in May 1999. This study also measured dissolved oxygen in the water column of inner Shelton Harbor.

Shelton Laundry and Cleaners, November 2003 and April 2004 Groundwater Monitoring Results (Ecology Publication)
Report on groundwater monitoring for concentrations and distribution of tetrachloroethylene (PCE) in samples taken at four monitoring wells at Shelton Laundry and Cleaners in Shelton, Washington in November 2003 and April 2004.

WRIA 14: Kennedy-Goldsborough Watershed Information (Water web site)
Water information on the Kennedy-Goldsborough watershed, including reports and data.

Partner websites

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