2023 Kitsap Water Quality Report

The Kitsap Public Health District’s  Water Pollution Identification and Correction (PIC)  program protects public health and prevents fecal pollution in Kitsap County surface waters.

Our environmental health employees sample dozens of streams and swimming beaches across the county for E. coli bacteria, an indicator of fecal pollution caused by human or animal waste. Fecal pollution can carry viruses, bacteria, and parasites that  make people sick .

We use water sampling results to notify the public of potential health risks, and to find and fix fecal pollution problems. This helps keep our streams, swimming beaches, and shellfish beds safe and healthy for the public to enjoy.

This Water Quality Report summarizes water quality monitoring results and highlights from the 2023 water year (Oct. 1, 2022 to Sept. 30, 2023).

Highlights from our work in Water Year 2023.

Note: Kitsap Public Health District monitors surface water quality in unincorporated Kitsap County with funding from County stormwater fees and within Poulsbo city limits through a monitoring services contract.  Because of this, our Water Quality Report does not include data for streams contained entirely within Bainbridge Island, Bremerton, or Port Orchard city limits.

Through sun, rain and snow, our Water Pollution Identification and Correction (PIC) team is in the field year-round, keeping tabs on the waters Kitsap residents share and love.

Our mission is to protect the public from waterborne illness and other water quality-related hazards. Water that is polluted with fecal bacteria is our primary concern because it can make people sick when swimming or eating shellfish. 

You might see our environmental health specialists in bright green vests wading the shallows at local swimming beaches, bushwhacking through soggy ravines, or tromping Puget Sound shorelines. Feel free to give them a wave and say "hi." Our team is always happy to answer questions about our work.

You can support our mission by keeping your septic system maintained, picking up after your pet, and keeping farm manure away from surface water (find more tips at end of this report). Together we make Kitsap County a safe and healthy place for all!

For more information on the program, contact PIC at 360-728-2235.

All creek systems in Kitsap County eventually drain into Puget Sound. Many  flow into shellfish growing areas . Because of this, pollution in surface waters contributes to contamination of shellfish beds. By reducing pollution in surface waters, our PIC program improves water quality in shellfish growing areas.

Since PIC work began a quarter-century ago, there has been a net increase of more than 5,000 acres of shellfish beds approved for harvest around Kitsap County.

The Health District issues public health advisories for streams that have consistent problems with high bacteria levels. Advisories are posted to protect the health of people who might come into contact with stream water, especially children.

The Health District adopted a new advisory threshold in 2022 to incorporate changes to the state water standard.

The Health District will issue an advisory when E. coli bacteria in water samples collected over a one-year period exceeds a geometric mean value (GMV) of 320 E. coli per 100 milliliters.

There are no public health advisories in effect for streams in 2024. No streams exceeded our advisory threshold based on sampling results for water year 2023.

The state Department of Ecology  establishes standards for surface water quality.  The freshwater standard is applied to “primary contact” water bodies, where people are likely to become submerged or ingest water through recreational activities such as wading and swimming.

The state standard for freshwater is based on the geometric mean value (GMV) of E. coli (EC) bacteria identified in 100 milliliter (100 ml) water samples. The geometric mean represents the central tendency of a dataset. Bacterial concentrations can be highly variable, so the geometric mean is useful for assessing trends.

In 2021, Washington state adopted E. coli bacteria instead of fecal coliform bacteria as the basis for its water quality standard. This change aligned the state standard with the federal standard and more accurately represents disease risks.

Use the interactive map below to explore water quality sampling results for streams monitored by the Kitsap Public Health District. Mobile users can  view the dashboard here .

The Health District monitors for health risks at  17 lakes across Kitsap County  during summer months to help keep swimmers healthy.

The Health District issues health advisories when water samples show high levels of E. coli bacteria at swimming areas or when potentially toxic cyanobacteria (blue-green algae) blooms are present.

E. coli indicate the presence of fecal pollution. Fecal pollution can carry viruses, harmful bacteria and other pathogens that make people sick.

Some cyanobacteria blooms  produce toxins . At high levels, these toxins can make people sick and kill animals.

We issued advisories for Kitsap Lake and Mission Lake in Water Year 2023.

If your family frequents swimming beaches during the summer, sign up to receive health advisories by email or text. Go to  kitsappublichealth.org/subscribe . Current water quality advisories are posted at  kitsappublichealth.org/beaches .

You can also follow the Health District on  Facebook ,  Twitter  and  Instagram  to stay up to date.

There are many sources of fecal pollution in surface water. Some sources, such as waste from wildlife, occur naturally and are difficult to prevent. Other sources, including sewage leaks and pet waste, can be prevented by people and organizations.

The video below explains basic pollution sources and preventions steps. Learn more at  cleanwaterkitsap.org .

The Kitsap Public Health District’s water quality work is made possible by  Clean Water Kitsap , a multi-agency partnership that receives funding from county stormwater fees. Clean Water Kitsap protects people, property and natural resources by reducing flooding and stormwater runoff, and preventing stormwater pollution.