Biogas and Biosolids Evaluation: Digester 1 Cleaning

The City of San Mateo is seeking a qualified contractor to clean and prepare the interior of its existing anaerobic digester (Digester 1) so that the unit can be inspected and condition‑assessed. The work includes safe shutdown, pre‑draining, gas purging, removal and off‑site disposal of remaining contents, high‑pressure interior washing, erection of interior scaffolding, and surface preparation. The contractor may also provide temporary on‑site dewatering systems at its discretion. This is a sealed‑bid solicitation; bidders must purchase the full set of plans/specifications via Barker Blue and submit a bid bond of at least 10 % of the bid amount. The estimated construction cost is $1.1 million, and the contract’s substantial completion period is 130 working days. • Scope: interior cleaning, waste removal, high‑pressure wash, scaffolding, surface prep for one anaerobic digester. • Required: California Class A contractor license, bid bond ≥10 % of bid, purchase of contract book via Barker Blue. • Timeline: Publication 9/16/2026, bid deadline 10/14/2026 2 PM, 130‑day completion period after notice to proceed. • Estimated value: $1.1 M (construction cost estimate). • Mandatory compliance: prevailing‑wage, DIR SB 854 registration, health‑order safety protocols.