Seattle Public Utilities estimates the cost to remove and replace a sewer line impacted by a significant amount of cement entering the system in Madison Park will be more than $1 million by the time the issue is fixed.
SPU spokesperson Mary Kelley declined to provide any substantive information regarding how this issue arose, directing the Madison Park Times to submit a public records request.
Those records show that the issue arose at the site of a single-family residence at 3820 E. Howe St., where the owner was having a single-family residence torn down to make way for a new two-story home. Eric Jones received demolition and construction permits on March 21.
A private contractor notified SPU’s Operations Response Center of a sewer backup in a pipe running north and south in the western part of 39th Avenue East on Aug. 15. The pipe was checked with a camera, and cement slurry was found in the line. An SPU State Environmental Protection Act Emergency Repair memo issued on Aug. 21 states the mainline was 20-40 percent filled with slurry, and attempts to clear the line were unsuccessful. That meant putting in a bypass pump to avoid any sanitary sewer overflows.
“The sewer mainline runs approximately north/south impacting 250 feet of pipe between East Blaine and East Newton Street,” according to the document. “…The proposed work is considered an emergency (SMC 25.05.880) because it needs to be undertaken quickly to prevent an imminent threat of serious environmental degradation, due to possible failure of the sewer main and the associated risks to public health and safety and public and private property.”
While SPU tells the Madison Park Times it is still attempting to find the responsible party, a letter from SPU claims and litigation advisor Eric Duncan was sent to March-MacDonald, Inc. on Oct. 1. The contractor had been working at the construction site since July, according to city records.
“Once repairs are complete SPU will invoice you for costs that will include response and repair of the damage,” the claim notification letter states, adding March-MacDonald should identify subcontractors who handled shoring work at 3820 E. Howe St.
SPU had to skip the normal bidding process due to the imminent threat of system failures and sewer backups, and issued a $381,300 Red Packaged Emergency Contract to Titan Construction for bypass pumping, traffic control and trenchless obstruction removal.
Efforts to remove the grout using an inpipe robotic method were stalled because it had filled the brick maintenance hole (MH).
“Titan has stated they could try removal of the grout in the MH and restore the flow channel by using an impact hammer, or they can excavate and replace the MH in kind using Seattle standard specifications and standard plans,” reads a Sept. 19 SPU Construction Management Division field memo. “SPU is directing Titan to attempt the removal of the grout from the brick MH with the full understanding that the removal technique may cause damage to the MH causing to need to be replaced.”
The grout was thought to have ended 55 feet south of the maintenance hole, but crews found it actually went 128 feet, according to an Oct. 8 email from Jade Sullivan, manager of small projects and emergency contracting for SPU’s Construction Management Division, to SPU Rehab Program manager Caroline Barlow.
“In addition, the grout was not easily removed and about 20 feet of pipe north of the manhole sustained damage to the host pipe,” the email reads. “It was found that the liner had bonded to the liner and grout removal by robotic method was no longer possible without destroying the existing liner.”
Titan had reached $448,000 in its Red Package rates by the time it was decided that excavation and restoration would be needed, which required a $395,000 change order. Added to the estimates for restoration were $206,000 in soft costs and $40,000 in contingency costs, according to the email, for a total budget projection of $1,093,000.
Kelley told MPT in early October that the excavation and replacement work was expected to last up to six weeks.
“There is temporary loss of some on-street parking and lane closures on 39th Avenue E., although local access will be maintained,” Kelley wrote to MPT.