City replaces problem sewage lift station, pipe
EVERETT - A sewage lift pumping station due for replacement likely caused the pipe break that let loose one million gallons of untreated sewage this spring.
The city is fast-tracking new construction to prevent future incidents.
The state Department of Ecology fined the city $4,000 over the April break that sent untreated sewage through a resident’s yard and into North Creek near Silver Lake. Everett came to an agreed order with Ecology last month and it mandates the city build a new pipe by April 2013.
The city is building a 5,000-foot force main that meets the order. Public works crews concluded over the summer that the entire pipe needed replacement.
Concurrently, the city is replacing the lift pumping station that connects to the pipe. The lift station uses pressure to move sewage uphill to the wastewater treatment facility.
The new force main will cost up to $3.4 million. The new lift station will cost $4.75 million. The money will come out of the city’s utilities fund, which is paid for with water and sewer bills.
The city signed a contract earlier this year to replace the lift station and is expected to be finished by next fall.
The lift station has problems with pressure surges and was at the end of its life.
In the city’s 2007 sewer comprehensive plan, the station in question in the 12000 block of Silver Way had failing grades for overflows, mechanical failures and pressure surges. None of Everett’s other 30 lift stations received worse marks.
The lift station’s pressure issues probably broke the pipe, public works spokeswoman Marla Carter said last week.
“It is very likely that the frequent pressure surges due to pumps’ on-off operation in (the lift station) have contributed to the failure of the force main,” Carter said.
The city had repaired three smaller leaks in 2011 on the same pipe segment that failed in April.
The iron pipe was installed in 1981. Public works was expecting it to last until at least 2030. The April spill was a surprise. When a corrosion consultant inspected the pipes after the 2011 leaks, the consultant didn’t find any issues, Ecology noted.
In May, the City Council fast-tracked a plan to replace 1,500 feet of the pipe. Crews found over the summer that more than 3,000 additional feet of the pipe needed replacement.
The first 1,500 feet of pipe should be built by this week, Carter said.
The spill sent one million gallons of sewage through a resident’s yard and ended up in North Creek, which feeds Lake Washington by way of the Sammamish River.
The city settled with the resident for $200,000 earlier this year, city spokeswoman Kate Reardon said.
The City Council signed off on the agreed order with Ecology at a September meeting. The order also requires Everett to evaluate its sewage lines for other problems and report to Ecology by June on any further fixes that are required.
Check out our online Publications!