Unmapped utilities add nearly $207,000 to SR150 sewer project

CHELAN — Unmapped utilities, an unexpected sewer-line conflict and a previously unidentified marina connection have added nearly $207,000 to Chelan’s State Route 150 sewer main replacement project, which is now physically complete.

The Chelan City Council unanimously approved a $206,931.35 change order with contractor J&K Earthworks on Sept. 8, increasing the original $3.57 million construction contract by approximately 5.8% to $3.77 million.

Public Works Director Jake Youngren said crews encountered numerous unforeseen conditions while replacing the sewer main, including water services, storm drains and sewer laterals that were either unlocated or absent from project plans. Trench stability problems also required wider excavations, additional restoration and slower work in some areas.

Under the contract, work resulting from unknown conditions could be handled through a “force account,” with the contractor documenting the labor, equipment and materials required and the city reviewing those costs afterward.

J&K Earthworks submitted $190,909.46 in force-account costs. Following review of individual work records against field reports and project specifications, the city determined $137,656.10 was justified.

Youngren told council members the review took roughly a month and a half.

“We encountered substantial unforeseen circumstances during construction, numerous unlocated, unmapped utilities, kind of the typical stuff, but very frequent,” Youngren said.

One of the largest complications involved the North Shore Interceptor, the sewer line carrying flows from Manson that Chelan also shares in using.

Youngren said the infrastructure was not shown in city records as crews ultimately encountered it and was located directly over the project trench. That conflict accounted for approximately $43,000 of the negotiated force-account costs.

Another $69,275.25 resulted from connecting an existing six-inch side sewer serving the marina to the new 15-inch sewer main. The connection was not visible during the city’s preconstruction investigation, which included crews using cameras to search the existing sewer system for side connections.

“[We] ultimately determined that it did have an independent sewer service,” Youngren said. “So we had to go back and cut it in.”

The marina work required connecting the line approximately 65 feet from a new manhole, installing a cleanout and removing and replacing asphalt, curb, gutter and sidewalk. The city directed the work to proceed before a final price was established because of scheduling needs.

Change Order No. 2 combines the $137,656.10 in negotiated force-account work with the $69,275.25 marina connection. The project’s first change order affected only the construction schedule and added no cost.

Youngren said a budget amendment will likely be needed once the final payment is processed and the project’s exact cost is known. He told council members adequate funding remains available across the two projects covered by the larger funding package.

The Sept. 8 action is expected to bring the SR 150 sewer main project to contractual closeout following completion of the physical work.

Andrew Simpson: 509-433-7626 or andrew@ward.media