Pierce County officials on Friday warned people to stay out of the waters off Chambers Creek Regional Park in University Place after 200,000 gallons of "partially disinfected" sewage accidentally was discharged into Puget Sound earlier this week.
The discharge occurred Wednesday after a mechanical failure at the Chambers Creek Regional Wastewater Treatment Plant, county officials said Friday.
Red "Closed" signs have been posted at the park's beach off Grandview Avenue notifying swimmers, waders and boaters to avoid contact with the water until further notice. People who come into contact with the water should wash well with warm, soapy water and also launder their clothes, officials said.
Water-quality experts with the Tacoma-Pierce County Health Department are testing the water for unsafe levels of bacteria, the county reported.
"The effluent was fully treated although a portion did not receive UV exposure during the disinfection stage due to a temporary system outage," said Carl Every, the county Public Works and Utilities sewer division manager. "We immediately took samples and determined we did not exceed our discharge limits."
Every said the spill did not appear to violate the conditions of a national permit that allows the county to dump wastewater into the Sound.
One of three channels funneling sewage through the UV disinfection system went down for about 30 minutes before a technician discovered the problem and corrected it, the county said.
On Thursday, county officials notified the state Department of Ecology of the accidental discharge and began working with the Health Department on Friday to issue a water advisory as a precaution.