To identify if the bacteria are from human sewage, tests for the presence of specific bacteria such as Escherichia coli or Pseudomonas aeruginosa have been used. This provides information on the species of animal which added the bacteria to the water. These concentrations are often exceeded in urban streams in King County. The Seattle - King County Public Health Department determines the public health implications of the bacteria data collected from this program and conveys this information to elected officials and the public. Currently no King County beaches are closed due to fecal coliform concentrations exceeding state standards.
Closed beaches are well marked with signs alerting people to the closures .
The current regulations allow local health officers to determine if a facility is polluted or not. The state Department of Health has not developed pollution standards for bathing beaches. The ten state standard which is a geometric mean of 200 fecal coliform with no single sample exceeding 1000. There is no standard approach among local health departments regarding when or if a beach is closed. Nor is there a consistent indicator or level of contamination used for signaling the need for a closure action.