The Astoria City Council on July 21 authorized Change Order No. 1 for the reservoir covers repair project, approving an additional $50,000 for specialized disinfection and related work and authorizing a revised contract amount of $174,502 with a potential not-to-exceed total of $182,381 including contingency.
Public Works staff said an annual inspection of Reservoir 2 found five degraded panels in the polyethylene geomembrane cover. The material supplier’s warranty covers the replacement material, but the original contractor’s labor to replace the panels is not covered, so the city must pay for removal, reinstallation and a more thorough disinfection process.
City Manager Spence and Public Works Director Jeff Harrington explained the work will require inflating the cover, applying a high-concentration disinfectant (such as chlorine) and specialized equipment (powerful blowers, handling equipment, and contractor labor). Staff said the disinfection portion of the work will cost about $50,000 and includes a mobilization fee of roughly $8,000; some city staff support reduces the overall contractor cost.
Councilors asked for clarification about the warranty and the scope of the additional costs. Harrington said the membrane material itself came with a 20-year warranty that covers materials but not the contractor labor. He said the early deterioration may have been related to construction conditions and extreme heat at installation, but staff could not state a definitive cause. The city had not identified similar failures among peer agencies, he said.
Councilor Lum moved to authorize the change order with Layfield Group for an additional $50,000; Councilor Davis seconded. The motion carried by unanimous voice vote.
Staff said the work is specialized, will be done by a contractor with specific equipment and crew costs per day, and the contractor will perform the disinfection and replacement under city supervision. The council did not change service levels or rates at the meeting.