• Collecting water quality samples in over 50 streams on a monthly basis. The data is used to create a Water Quality Index (WQI) - a way to monitor water quality trends in streams over time.
• Collecting stream insects (benthic macroinvertebrates) from over 30 streams per year. This data is used to create a Biological Index of Biotic Integrity (BIBI) - a way to assess overall stream health based on which insects are able to survive in the stream. 
• Shellfish sampling in the Key Peninsula-Gig Harbor-Islands (KGI) watershed to check for fecal coliform bacteria contamination.

• Instructions for accessing the data portal and glossary
• Access the data portal 
• Washington State water quality standards on freshwater and saltwater 

How Streams Get Their Grades
We issue an annual Surface Water Health Report Card on the health of surface water quality in each major watershed.  The report card grades a number of streams on a scale of "A" to "F" based on a combination of WQI scores, BIBI scores, and if the stream is listed as impaired per Section 303(d) of the federal Clean Water Act.  These factors combined provide a realistic overall understanding of stream health, and help direct our clean up efforts.  The report card also includes an assessment of some lakes in the county.  View most recent report card | View all report cards

Additional Resources

• Puget Sound Benthos Database 
• Washington's 2020 Clean Water Plan
• Pierce County's Municipal Stormwater Permit
• Glossary of terms for water quality