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Our shoreline provides tremendous value to our communities – from swimming, beach walks, and fishing, to shellfish harvesting and boating. Vashon-Maury Island’s beaches are a treasure for residents and visitors alike. But when our recreational waters become polluted with human or animal poop, this fecal pollution can make us sick.

Current project

North Colvos Passage Project

King County Water and Land Resources Division (WLRD) and Public Health - Seattle & King County (PHSKC) are working with property owners to find and fix pollution sources (such as pet waste, manure from hobby farms, wildlife waste, or failing on-site sewage systems (OSS)) in North Colvos Passage.


What we're doing

  • Conducting sanitary surveys and sampling shoreline tributaries in the Northern Colvos Passage area to identify sources of fecal coliform bacteria. If pollution is identified, we will use a systematic approach to find the source.
  • Collaborating in partnership with professionals and community members to identify and implement pollution solutions.
  • Connecting with community members and building mutual understanding of how individual actions can reduce fecal pollution in their area.

What you can do

  • Find ways to make sure that no poop is entering the water. For example, make sure to pick up dog droppings on the beach and in your yard.
  • Attend workshops and events when available (see event schedule)
  • Farms can work with King Conservation District for management plans to ensure manure from farm animals does not cause pollution.
  • Help us to perform water sampling and visual surveys by giving consent for samplers to access your shoreline (in project focus areas only)
  • Perform septic maintenance for a rebate of up to $300 (in project focus area only)
  • Submit a pollution complaint if you are worried about pollution in your area by calling us at 206-477-8050 or use our online form.

Keep the beaches swimmable, fishable, and diggable

  • The Vashon-Maury shoreline provides value to the community in swimming, beach walks, fishing, boating, and shellfish harvesting.
  • Shellfish growing areas have been downgraded, water quality has declined, and fecal pollution from humans and animals is of grave concern.
  • Pollution sources can impact property owners resulting in costly repairs, property damage and liability.
  • By working together, we have already fixed many pollution sources.

Previous successes

Over the past decade, PHSKC, Vashon homeowners, and other partners have made large investments in reducing pollution and improving water quality. The investment improved water quality and resulted in reopening 493 acres of shellfish harvesting areas.

In 2018-2020, PHSKC had a similar project in Outer Quartermaster Harbor, Neill Point, and several beaches along East Passage. During this time, we:

  • Collected 352 water quality samples
  • Hosted 4 workshops and provided information or technical assistance to over 1,000 property owners
  • Found 10 new fecal pollution sources
  • Provided a septic maintenance rebate to 18 properties

Water quality sampling

To make sure that excessive fecal bacteria are not affecting the water around Vashon-Maury Island, King County staff will sample freshwater flows onto the beaches along Puget Sound. Vashon residents may see County workers collecting fresh water samples along the beaches. County staff will only sample where there is public access or where they have permission from property owners to access private property.

Learn more on the Water quality sampling webpage.


Contact us


This project has been funded wholly or in part by the United States Environmental Protection Agency under Assistance Agreement PC-01J18001 to the Washington State Department of Health. The contents of this information do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.

Mark your calendars!

Join us on Zoom for our first Q&A session

  • Friday, Sept. 25, 2020 at 4:00pm
  • Saturday, Sept. 26, 2020 at 11:00am

Phone option: call +1-253-215-8782
– meeting ID: 509-175-3331
– passcode: 978271

  • Hear about the new Colvos Passage project
  • Meet the project team
  • Tell us why healthy beaches are important to you

If you have a specific question, contact us before the session to make sure that we will answer it.

Septic Maintenance Rebate

We are offering a rebate of up to $300 for septic maintenance activities performed in the project focus areas.

To be eligible for the rebate:

  • Contact Public Health about preventing pollution on your property
  • Complete an online septic maintenance workshop (workshop dates posted above)
  • Complete septic system maintenance: inspection, riser installation, and/or pumping

Contact us to apply for the rebate.

Deadline: December 31, 2021

Funding for rebates is limited. They will be given on a first-come, first-serve basis until funding is exhausted.

A community event on Vashon Island to educate the public about safe onsite septic systems.

A community event on Vashon Island to educate the public about safe onsite septic systems.

Vashon Island beach inspection

A field worker doing onsite inspection at a Vashon Island beach location


Link/share our site at www.kingcounty.gov/oss/pic