Mason County annual BEACH report

We monitored three beaches weekly in Mason County from May 20 – Aug. 30, 2019:

  • Belfair State Park
  • Potlatch State Park
  • Twanoh State Park

 


Twanoh State Park Beach in Mason County

Keeping beaches safe

The Beach Environmental Assessment, Communication & Health (BEACH) Program ensures that marine water is safe to swim and play in and informs the public if water doesn't meet swimming standards.

From Memorial Day through Labor Day in 2019, we sampled 62 public high-use beaches statewide, either weekly or biweekly, for enterococcus, a type of fecal bacteria. High enterococcus levels are linked to swimmer illness.

Mason County saltwater swimming beaches

We monitored three beaches weekly in Mason County from May 20 – Aug. 30, 2019. 

Find details about each of the Mason County beaches below:


Data summary: Bacteria results compared to standards

The chart below summarizes the bacteria levels at Mason County beaches in relation to the EPA swimming standard or saltwater swimming criteria. Beaches are considered unsafe for swimming when the geometric mean of enterococcus/100 mL of water is greater than or equal to 30 and the statistical threshold value of enterococcus/100 mL is greater than or equal to 110. We issue a public swimming advisory when enterococcus levels exceed 104 per 100 mL of water. 

Table: Calculated geometric mean and statistical threshold value at Mason County beaches (in enterococcus per 100 mL) for 2019

Beach Geometric Mean Statistical Threshold Value
Belfair State Park 13 26
Potlatch State Park <10 11
Twanoh State Park <10 10