Post Falls officials say as much as 130,000 gallons of raw sewage spilled from the city’s wastewater system over the weekend, and they aren’t sure whether it will seep into the Spokane Valley-Rathdrum Prairie Aquifer, the region’s source of drinking water.
“Some of it is still soaked in the soil,” said Terry Werner, the city’s public works director. “Will it get down into the aquifer? That’s why we hired a hydrologist.”
Police reported the spill – the second in Post Falls in the past year – about 5 a.m. Monday at the Idahline Lift Station, a facility that collects and lifts wastewater to a higher elevation.
City crews responded within 15 minutes, and the site has been cleaned up, treated and covered with a clean layer of soil, said Kit Hoffer, city spokeswoman. A hydrologist will monitor the spill’s effects, Hoffer added.
The station’s alarm system did not detect the spill because of a broken wire, city officials said. Though it is still unknown when the spill began, Hoffer said, the city determined all alarms were working Saturday morning.
Construction work has been going on at the station at Fifth Avenue and Pleasant View, and Werner believes vibration from equipment, truck traffic and the compacting of soils likely caused a thin wire in the alarm system to break.
The estimated amount of sewage that spilled is the “worst-case scenario,” Werner said,
Last September, as much as 10,000 gallons of sewage spilled onto the ground at the city’s Fourth Street treatment facility because of a power failure.
The Idahline station’s alarm system has been repaired, city officials said. Results from the hydrologist could take 30 days.
“At this stage we’re just waiting to hear what the hydrologist says,” Hoffer said. “We’re getting back to normal.”