Lake Water Quality
The Environmental Health Unit (EHU) of the Cowlitz County Health & Human Services Department (HHS) administers water quality grants funded jointly by Washington State Department of Ecology (ECY) through the Centennial Clean Water Program and HHS. As projects are completed, specific water quality results are available on ECY's Environmental Information Management System. See below for more information about each grant awarded.
Check out our printable brochure on ways to help Silver Lake, or any lake!
For information on protecting Washington waters, visit Ecology's website.
If you have questions or comments regarding the water quality program, contact Season Long at LongS@cowitzwa.gov.
In April of 2015 work was started on the study Water Quality Testing & Improvement at Two Cowlitz County Lakes. Specific results are available on ECY's Environmental Information Management System. A project summary is provided in the Project Outcome Summary Report.
Testing was conducted on Silver Lake from September 2015 to February of 2018. Planning documents available include the Quality Assurance Project Plan and Standard Operating Procedures. Summary of results are available in the Final Report – Silver Lake.
|Testing was conducted on Horseshoe Lake from March 2016 to February 2018. Planning documents available include the Quality Assurance Project Plan and Standard Operating Procedures. Summary of results are available in the Final Report – Horseshoe Lake.|
For more information, click here to view a presentation given to the Cowlitz County Board of Health in July 2016.
|In September 2018, work was started on the study Silver Lake Sediment and Water Quality Testing Plus Engagement Project. Results include two years of testing the lake and the inlet streams on a monthly basis, and one sediment testing event of the lake bottom.|
The project began in February 2018 and ended on December 31, 2022. Planning documents available include the Quality Assurance Project Plan and Standard Operating Procedures.
This project compared phosphorus, E. coli, and standard water quality parameters of two major inlets, Sucker and Hemlock creeks, to determine their impacts on Silver Lake. Additionally, lake sediment was evaluated for contaminants of concern. Below is a summary of the results over the course of the study. The summary of results is also available in the Final Report – Silver Lake.
Digitization: This project also included digitization of the Silver Lake Watershed Management Plan, making it more accessible to the public. The original document was written in 1994 by the Cowlitz County Conservation District and included Darin B. Houpt, Forest Hydrologist, and Resource Technicians Joanne Aylesworth and Steve Stinson.The digitized plan is available by using the following links: