Basics
Healthy Human Population
Outdoor Activity
Indicator
Condition of swimming beaches
Vital Sign Indicator
Percent (%)
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Beginning in 2022, 95% of core beaches meet safe swimming standards annually.

Target fact sheet

Memo to Science Panel with rationale

Heather Gibbs
Contributing Partners
Last Updated
01/07/2025 20:19:32
Map
Location of Puget Sound swimming beaches monitored for recreational water quality criteria. A beach that passes has no more than one exceedance event of the swimming standard during the swim season. In 2024, 9 Puget Sound marine beaches (6 core beaches) that were monitored failed to meet the recreational water quality standard.
Description

The "condition of swimming beaches" indicator reflects marine water quality conditions in areas heavily used for recreation. This indicator tracks the percent of swimming beaches that pass swimming standards with no more than one exceedance event of the swimming standard during the summer. Swimming beaches not meeting water quality standards indicate increased risk of people getting sick through gastrointestinal illnesses, respiratory illnesses, and skin infections.


Vital Sign Indicator Chart
Condition of swimming beaches
By: Core Puget Sound Beaches

The percent of Puget Sound core beaches that have no more than one exceedance of the swimming standard during the summer. Core beaches are a prioritized subset of all monitored beaches sampled every year. The method for calculating an exceedance of the swimming standard changed in 2022. Beginning in 2022, an exceedance is now recorded over a 7-day period and is called an exceedance event. Results from the new method are marked differently from earlier years.

The "condition of swimming beaches" indicator reflects marine water quality conditions in areas heavily used for recreation. Swimming beaches not meeting water quality standards indicate increased risk of people getting sick through gastrointestinal illnesses, respiratory illnesses, and skin infections.

Key Vital Sign Indicator Results
  • 84% of Puget Sound core beaches monitored during the 2024 season met the recreational water quality standard. This is a 2% decrease from 2023. Core beaches are a subset of all monitored beaches that are sampled yearly or almost every year since 2004 and are considered as the highest-use and highest-risk marine beaches in Washington.
  • Six core beaches had two or more exceedance events of the swimming standard in 2024. Those beaches are Indianola Dock, Pomeroy Park (Kitsap County), Jack Hyde Park, Titlow Park (Pierce County), Larrabee State Park, Wildcat Cove (Whatcom County), and Twanoh State Park (Mason County). Additionally, there were four non-core beaches that failed during the 2024 sampling season: Belfair State Park (Mason County), Boulevard Park near Taylor Dock, Little Squalicum Park (Whatcom County) and Hollywood Beach (Clallam County).
  • Since 2004, soon after the BEACH program started, many local bacteria problems have been identified and corrected through local pollution identification work. There are still year-to-year fluctuations in marine water quality at swimming beaches due to different factors, but many beaches are experiencing water quality improvements and the work to identify problems continues.
Methods
Monitoring Program

Washington State Department of Ecology BEACH Program

Data Source

Washington State Department of Ecology BEACH Program and BEACH Annual Report

Washington’s BEACH Program was launched in 2003 in response to the BEACH Act, which amended the U.S. Clean Water Act in 2000. Washington's program is a collaboration between the Department of Ecology, Department of Health, Tribes, local health jurisdictions, and volunteer groups. During the sampling season (Memorial Day to Labor Day) BEACH partners monitor high-use/high-risk beaches throughout the Puget Sound and Washington’s coast.

For this indicator, a beach that passes swimming standards means there is no more than one exceedance event of the swimming standard during the summer. The swimming standard is exceeded if bacteria levels are greater than 104 enterococcus/100mL.

The number of monitored beaches varies from year to year depending on availability of funding and where water quality issues arise. A subset of beaches, called the core beaches, are prioritized every year to be sampled. Many core beaches have been used to assess the trend in the condition of swimming beaches since 2004. There are about 43 core beaches (range is 36 to 48) and 60 total beaches (range is 46 to 76) sampled every year. Beginning in 2022, only core beaches are used to calculate the percentage of passing beaches given their long-term datasets and possible trends identified from improvements made at beaches by BEACH partners. 

The method for calculating an exceedance of the swimming standard changed in 2022. Beginning in 2022, an exceedance of the swimming standard (greater than 104 enterococcus/100mL) is now recorded over a 7-day period and is called an exceedence event. For example, if a beach fails to meet the swimming standard and a resample shows that bacteria levels have remained high, the exceedance is counted as one event. If bacteria levels remain high after a 7-day period, this would count as a second exceedance event. Previously, every sample with high bacteria levels from a beach counted as a unique exceedance. This new approach more accurately reflects that high bacteria levels from a source may take a few days to disapate from the environment. 

Critical Definitions

Enterococci bacteria: a group of bacteria found in the gastrointestinal tract of humans and other mammals. Decisions to post an advisory or close saltwater beaches to swimming are based on the amount of enterococci bacteria in the water that indicates human or animal feces are present.

Interpretation of Results

Most swimming beaches in Puget Sound have good water quality. However, bacteria problems may arise from faulty septic tanks, sewage spills, stormwater, and animal waste, including pet waste, farm animals, and wildlife. The source of contamination is different from beach to beach and is not always obvious. Some beaches have chronic bacteria problems that are difficult to solve. While, problems at other beaches may be quickly resolved and reflect localized problems rather than trends over all of Puget Sound water quality.

Water quality results fluctuate from year-to-year and at times may be attributed to environmental factors like weather. For example, after a long dry spell, a large rain event can cause an upland flush that increases bacteria levels in the marine water.

Fortunately, water quality problems at some beaches have been corrected. Pollution Identification and Correction (PIC) programs work to find and remove bacteria sources that harm human health at areas used for water recreation.

Datasets

No datasets uploaded.

Reporting Guidance
Reporting Instructions
Subcategories
Name
Core Puget Sound Beaches
2004-2021, 2022-present