High flows and cracked streets

While Spokane County roads seem to have taken the brunt of the recent rains and snow melt, cities on the West Plains have experienced their own set of problems.

Both Cheney and Medical Lake's water reclamation plants have seen unusually high flows from their respective sewer systems; something the Airway Heights plant seems to have dodged. Where all three cities have seen similar impacts is in their street conditions.

Circumstances last evening Thursday forced Medical Lake officials to take some emergency actions to prevent flooding from creating additional problems. City Administrator Doug Ross said they noticed manholes in the area of Campbell Street had become filled with water, or "surcharged," and that a sewer lift station serving the South Lake Terrace subdivision was at capacity, as were lines coming into and exiting the station.

Ross said part of the problem was residents in South Lake Terrace running sump pumps to clear basements, flooded due to high runoff created by rains and temperatures into the 40s melting the snow pack. This also led to a softening of the ground allowing water to flow into the manholes and thus into the mains.

Ross said the city contacted Big Sky Utilities, which sent a vactor truck that began pumping out the main on Campbell around 8:30 p.m. They were able to make sure nothing flowed back out of the manholes, and the truck finished around 11:30 p.m.

The system was still surcharged as of Monday, Feb. 27, and the city was still seeing high flows through its plant, which Ross said at one point peaked at 3.1 million gallons - the average is 430,000 gallons - and was likely down to around 1 million gallons. Ross said crews were also pumping water from Medical Lake itself, with the pump located in the wetland just north of the causeway going to Eastern State Hospital.

"We're still pumping a lot of water," he added.

The city of Cheney's treatment plant saw high flows as well, beginning around Feb. 16 and running through Feb. 22. Whereas the city's typical peaks average between 1.5–2 million gallons per day, Public Works Director Todd Ableman said during this period they average 5.4–5.8 million gallons.

Most of the city's system is gravity flow to the treatment plant. Of the three lift stations, all located east of the Burlington Northern Santa Fe railroad tracks, Ableman said only one became surcharged, the station serving four homes on Front Street.

The treatment plant has two duplicate sewage processing lines, Ableman said, that due to recent equipment upgrades, are capable of maintaining the aerobic digestion process. Plant personnel switched back and forth between these trains to accommodate the high flows and not over-tax the plant.

"We were worried that with the flows, we would have to open up both," Ableman said. "But it seemed good. All of our tests were coming out right, and the turbidity was fine."

Airway Heights Public Works Director Kevin Anderson said their treatment plant was experiencing only minimal increases in peak flows. The plant, which is newer than Cheney and Medical Lake facilities, averages about 700,000 gallons per day, with peaks usually averaging 900,000 gallons.

Anderson said this past week the facility had been experiencing peaks about 25 percent higher than the average.

"We're able to make operational tweaks for everything to work fine," he added.

What has been an issue has been impacts to streets. Anderson said they have been "inundated" with potholes, with several so deep they required filling with gravel first before crews applied cold mix patches over the top.

Anderson also said that soft soils, mainly north of U.S. Highway 2, have led to parts of roadways dipping. It's conditions Ross said are also happening in Medical Lake, rather than potholes, and particularly around State Route 902. He added that once things dry out, crews will have about 7–8 spots that will require "some digging" to fix.

"It will be a brutal spring and summer," Ross said. "We'll only be able to do the most severe because we just don't have any money."

Ableman said Cheney streets are pretty good for the most part, something he attributed to the city's ongoing arterial and street preservation work. Pavement cracking and sagging forced rerouting of bus traffic to Eastern Washington University using a portion of Erie Street between Elm and Cedar, and Department of Transportation crews were applying cold mix patches on parts of State Route 904.

"So far though, we're weathering the storm pretty good," Ableman said.

John McCallum can be reached at jmac@cheneyfreepress.com.