A pipe cracked at the Terrace Ridge Lift Station, located near 244th Street SW. and Cedar Way, and spilled sewage into Lyons Creek through a storm drain.
City workers found the leak at about 12:30 p.m. Friday, Sept. 9, and shut off the line within 20 minutes, said city public works director Larry Waters. According to water tests, city workers believe about 3,000 to 5,000 gallons flowed down stream before it was discovered.
“We suspect it might have been leaking for a day or so,” Waters said.
The incident is of greater concern to Lake Forest Park residents because the spill occured in the southeast edge of Mountlake Terrace and flowed downstream into Lake Forest Park, said the city storm water program manager Mike Shaw.
The city also contacted the state Department of Ecology, the city of Lake Forest Park and other local authorities about the incident.
Terrace Ridge Lift Station and the pipe that cracked was already scheduled to be replaced in 2006, Waters said. City workers completed repairing the pipe on Sept. 13.
City workers also went door to door and told residents near the creek about the spill, Shaw said.
To be safe, residents should avoid contact with the creek water for several weeks because of the spill, said Shaw. If you do touch the water, wash vigorously with a generous quantity of soap and hot water.
The accident released large quantities of fecal coliform bacteria into the creek, which is considered a health hazard, Shaw said. People have a higher risk of getting sick from waterborne diseases if exposed to large quantities of fecal coliform bacteria.
Small quantities of coliform occurs naturally in bodies of water like rivers, creeks and lakes, Shaw said. In some parts of Lyons Creek, city workers found coliform bacteria levels as much as 10 times higher than what the state Department of Health considers safe.
City workers will continue to take water tests and notify the public when the danger has passed, which could take days or weeks, Shaw said.
“It really depends on rainfall at this point,” Shaw said. “The more water that falls, the faster the fecal coliform bacteria will flush down the system or decompose.”
Last week’s spill is not as large as the Veterans Day spill last November. The Ceder Grove Pump Station, which is also near Lyons Creek, spilled about 150,000 gallons because the pump station lost power, the alarm system failed and pipe was aligned incorrectly.