Late-night work on the underbelly of Deception Pass Bridge will continue for a little longer and cost a little more than originally expected, according to City Engineer Joe Stowell.

A contractor has been working since March 27 on a project to replace the hangers that suspend a 10-inch water transmission line under the bridge. The pipe carries water from the Anacortes water plant on the Skagit River to the city, but is mainly a backup for the 24-inch water line that also runs under the bridge.

The work, which goes from 8 p.m. to 6 a.m., causes brief delays at the bridge as one lane is closed during that time.

Stowell said bad weather has caused the project to go on longer than originally anticipated. The under-bridge work is done with equipment that looks similar to a “cherry picker,” but has an articulated arm that can also move a platform downward to the underside of the bridge.

The workers don’t go out there when the wind is 35 miles per hour or higher, he said, which has happened quite a few times in the last month.

The work was expected to be wrapped up by May 25, but the city got their permit with the state extended until June 15. The primary work that remains is to paint the pipe to match the bridge.

“I don’t believe it will take that long for them to finish,” Stowell said.

The impetus for the project came from a citizen who noticed corrosion on the pipes and reported it. The city sent out inspectors who confirmed the problem.

Bridge Masters Inc. won the construction bid at $686,000. The city also contracted with KBA, Inc. as construction managers.

Stowell explained that workers discovered corroded pipe couplings last fall; fixing the problem added significant time and work to the project.

KBA’s original contract was for nearly $30,000, but the amount was increased to $75,000.

City staff proposed a second contract amendment to cover the increased cost due to the extension of the project. If approved by the city council, the total contract will be a “not to exceed” amount of $117,000.

Stowell said the city also plans to inspect the 24-inch pipe, which is made from ductile iron, throughout its many miles of length in order to look for areas of pitting and corrosion.