We monitored three beaches in Island County from May 21 through Aug. 31, 2018:
- Dave Mackie Memorial County Park
- Freeland County Park, Holmes Harbor
- Windjammer Lagoon
Freeland County Park in Holmes Harbor has a permanent swim advisory due to bacteria levels.
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 2018, 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.
Island County saltwater swimming beaches
We monitored three beaches in Island County weekly from May 21 – Aug 31, 2018.
Find details about each of the Island County beaches below:
During the 2018 swim season, Dave Mackie Memorial County Park had very good water quality. This beach was sampled 15 times during the monitoring season. All sampling events had bacterial levels in the safe swimming range.
A shoreline survey was conducted at this beach by BEACH Program staff on May 15, 2018.
Freeland County Park beach had a permanent swimming advisory from May 16 to Nov. 30. The advisory was issued because there were sporadic high bacteria levels during the months that beach wrack (decaying marine vegetation) accumulates on the beach. This beach was sampled 16 times during 2018. On May 21, sampling results showed bacterial levels in the closure range, but upon subsequent sampling results dropped into the safe swimming range.
During the summer, north winds cause beach wrack to accumulate along the southern Holmes Harbor shoreline. Beach wrack can be up to two feet thick in areas. In 2012 – 2013, a study was conducted at this beach by the Department of Health to determine if beach wrack could be a source of bacteria. The study showed lower levels of bacteria during the winter and spring seasons when beach wrack was not present in such great amounts. High bacteria levels during summer months may be part of a natural condition at this beach.
A shoreline survey was conducted at this beach by BEACH Program staff on May 15, 2018. A recommendation to the county was made that water quality signage should be more visibly posted. We also recommended maintaining the seasonal advisory.
During the monitoring period, Windjammer Lagoon had very good water quality with low bacteria levels. This beach was sampled 15 times during the monitoring season and met swimming standards for all periods sampled.
Data summary: Bacteria results compared to standards
The chart below summarizes the bacteria levels at Island 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 35 and the statistical threshold value of enterococcus/100 mL is greater than or equal to 276. We issue a public swimming advisory when enterococcus levels reach 104 per 100 mL of water.
Table: Calculated geometric mean and statistical threshold value at Island County beaches (in enterococcus per 100 mL) for 2018
| Beach |
Geometric Mean |
Statistical Threshold Value |
| Dave Mackie Memorial County Park |
12 |
26 |
| Freeland County Park, Holmes Harbor |
23 |
83 |
| Windjammer Lagoon |
12 |
26 |