Green Cove

Routine water quality testing in Thurston County has shown high levels of harmful bacteria in Green Cove Creek. Thurston County Public Health's Clean Water Program is doing more tests in Green Cove Creek to try to find the sources of bacteria.
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  • Monitoring Locations
  • Bacteria Results
    • The table below shows how many times laboratory results have shown high levels of bacteria at each monitgoring site in Green Cove Creek. sites with more frequent high results may be closer to bacteria sources.

      A result is considered high if over 320 Most Probable Number (MPN), the number set by the Washington Department of Ecology. Sites with average E. coli levels above this number are highlighted in red. Sites with average E. coli levels above 100 MPN are over the ideal protective level set by the State of Washington. They are highlighted in orange.

      The average concentration of bacteria means these sites are generally not safe for direct contact with the water. Bacteria can enter your body through the nose and mouth as well as through cuts and scrapes on the skin. We recommend you don't play in, wade barefoot or in sandals, or touch the water in Green Cove Creek.


      Number of high results

      Average result (MPN)


      7 out of 16



      10 out of 18



      3 out of 16



      4 out of 19


  • Status
    • ​We're working to get information out to your neighborhood and scheduling visits near areas with high levels of bacteria. Property visits are a chance for us to work together to prevent bacteria from entering our water. They are conducted outside, and you can choose to join us or stay indoors.

      If you receive a letter or postcard requesting a site visit, feel free to contact us with questions or to schedule. 

      Contact information:


  • What to expect during a property visit:
    • ​We'll review the components of your septic system and compare it to our records

      Collect water samples

      Look for possible sources of E. coli bacteria.

      Possible sources include:

      • Septic systems: Bacteria from failing septic systems can end up in Green Cove Creek. There are several programs that offer financial assistance for septic maintenance, including the Craft3 program and the Homeowner Grant Program for Septic System Maintenance.
      • Stormwater issues: Stormwater is water from rain that runs off land, rooftops and driveways and can enter nearby waterways. Stream Team has information on managing stormwater.
      • Pet Waste: Dog poop contains a lot of bacteria that can get into Green Cove Creek.  You can pick up a free pet waste bag dispenser for your neighborhood to help manage this. More information can be found on the Stream Team website.
      • Manure from chickens, cows, horses and other livestock. The Thurston Conservation District offers free technical assistance for this issue.
      • Feeding wildlife: This can cause animals to gather and their waste can get into Green Cove Creek. Please, DON'T feed wildlife.

  • What happens after the site visit is completed?
    • ​After the visit, we'll send a summary letter that details how you can address any issues we found. We may refer you to other resources who can provide free technical assistance and may connect you to funding to make water quality improvements.

      While these visits are voluntary and we really appreciate you scheduling, if we do see anything on your property, such as a failing septic system or nonpoint violations in the form of E coli contamination entering the stream from your property, we will require you to fix or address the issue. We have some assistance to help with septic repairs you may qualify for, such as the Craft 3 low interest loan program


Email Tamara Cowles or call 360-490-3423

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