Juanita Creek’s history of bacteria spurs all-out water sampling effort

A long history of frequent beach closures has prompted one of the most intensive sampling efforts now underway along Juanita Creek.

A long history of frequent beach closures has prompted one of the most intensive sampling efforts now underway along Juanita Creek.

The water samples, which the King County of Natural Resources and Parks Department started collecting throughout the watershed July 27, will allow officials to identify where high bacteria counts are coming from.

“We’ve had problems with the swimming beach at Juanita for a long time,” said Jonathan Frodge, senior limnologist for the department. “We’ve shut Juanita Beach down more than any other beach in the county.”

Through King County’s Swimming Beach Monitoring Program that monitors several sites in the area during the summer months to determine levels of bacterial pollution and relative human health risks, officials have found Juanita Creek to be one of the “top bad actors,” along with Thornton Creek, Frodge said.

The incidence of high bacteria in which Juanita Creek holds the record for spans longer than 10 years, he added.

The most recent closure of Juanita Beach Park’s swimming area occurred earlier this month when fecal coliform levels rose up enough to cause concern. As the elevated counts of the bacteria indicated possible sewage pollution, the Public Health Department determined the water was not safe to swim in and the city of Kirkland closed the beach Aug. 7. After samples met standards for three consecutive samples, the city reopened the beach Aug. 12.

Working with King County, the city of Kirkland recently received a grant from the Washington State Department of Ecology that is providing funds for the sampling. Because Juanita Creek already had a history of high bacteria and it empties into a public beach, it is considered a priority for the pollution-control project, Frodge said.

The county already has taken nearly 200 samples throughout the watershed and today teams will be along Juanita Creek taking nearly 200 more. This will include several sites along the waterfront of the swimming beach.

In October during the rainy season, King County of Natural Resources and Parks Department will take several more samples before it combines all the sampling data.

“We’re trying to find out where it’s coming from because we can’t fix the problem until we can find it,” Frodge said.

The usual suspect for the bacteria source at Juanita Beach has been the urban runoff that enters adjacent to the beach from Juanita Creek, said Jenny Gaus, surface water engineering supervisor for Kirkland Public Works. Urbanized water could be attributed to any number of factors, including wildlife, geese, pet waste and broken sewer lines.

The main stem of Juanita Creek originates east of Interstate 405 and flows about five miles west and south, entering Lake Washington on the west side of Juanita Beach Park. The Juanita Creek drainage basin is approximately 4,000 acres. Land use in the area is considered highly developed.

“We’re hopeful that we will be able to find where the sources are in the watershed so we can take care of the problem, but also learn from the study and use the results in other areas of King County,” Frodge added.

Carrie Wood can be reached at 425-822-9166, ext. 5050 or cwood@reporternewspapers.com.

Learn more

For more information about Juanita Creek, visit www.kingcounty.gov, click on environment and search Lake Washington watersheds.