Contra Costa Water District approves $5 million construction contract for Randall-Bold treatment plant upgrades

Contra Costa Water District approves $5 million construction contract for Randall-Bold treatment plant upgradesThe district board has unanimously awarded a construction contract to TNT Industrial Contractors to replace aging chemical feed and sludge collection equipment, and to address hydraulic concerns at the 50 MGD facility.

TNT Industrial Contractors secured the construction contract with a $4.67 million base bid, narrowly beating six other bidders and landing within 2.5% of the engineer's estimate.

The project will replace mechanical equipment dating back to 2007 in the sedimentation basins and address corrosion and hydraulic issues in the clearwell.

A permanent bypass will be installed to ensure uninterrupted water supply to the Diablo Water District during future clearwell maintenance outages.

The board also approved a $217,698 contract amendment with Water Works Engineers, LLC for design services during construction.

The Contra Costa Water District (CCWD) Board of Directors unanimously approved a construction contract worth up to $5.04 million for improvements at the Randall-Bold Water Treatment Plant during its May 20, 2026, meeting. The contract was awarded to TNT Industrial Contractors, whose $4.67 million base bid emerged as the lowest among seven competitors. According to Stan Ali, a construction manager within CCWD's engineering department, the highly competitive bidding process resulted in a winning bid that was within 2.5% of the district's $4.5 million engineer's estimate. The approved total includes an 8% change order authority of $374,051. Built in 1992 and last significantly upgraded in 2007, the Randall-Bold facility operates at a capacity of 50 million gallons per day (MGD). It is jointly owned by CCWD and the Diablo Water District under a joint powers agreement, with CCWD responsible for operations and capital improvements. The capital improvement project will address multiple operational and safety concerns at the facility. Key scope items include replacing worn-out chemical feed piping and sludge collection equipment in the sedimentation basins, which have been in continuous operation since 2007. The project will also resurface the U-shaped launder troughs that guide clarified water through the plant. At the back end of the facility, the contractor will address hydraulic concerns and corrosion within the clearwell's inlet piping. Crucially, the project includes the installation of a permanent bypass system. This will allow CCWD to drain the clearwell for future maintenance while continuing to supply water to the Diablo Water District. To support the construction phase, the board also authorized a $217,698 amendment to an existing professional services agreement with Water Works Engineers, LLC. This brings the design firm's total contract to $1,556,698 to provide submittal reviews and design clarifications as the physical upgrades are executed.