REPORT TO COUNCIL
SUBJECT
Title
Award of Contract for Water Tank Mixing Systems (F16-63)
Report
REPORT IN BRIEF
Approval is requested to award a contract to PAX Water Technologies of Richmond in an amount not to exceed $332,439 for the purchase of seven (7) water mixers and eight (8) water quality stations to be installed in water tanks at the Hamilton, Mary-Carson, Wolfe-Evelyn, and Wright water plants. The total cost will be partially offset by a PG&E rebate in an estimated amount of $21,474.
EXISTING POLICY
Pursuant to Chapter 2.08 of the Municipal Code, a contract for goods and/or services may be exempt from competitive bidding requirements when the goods or services are available from a sole source.
ENVIRONMENTAL REVIEW
N/A
BACKGROUND AND DISCUSSION
Tank mixing systems are used to circulate water within tanks in order to keep the quality of the stored water from deteriorating. Water that is not mixed can become thermally stratified and lose its disinfectant residual; water that is mixed remains at a constant quality, meeting State of California Title 22 requirements. The City currently uses large centrifugal pumps to mix the water, but they were not designed for this purpose and their use is energy-inefficient and costly.
The PAX mixer is an active, submersible system that mixes large volumes of water using a patented impeller, which establishes a stable flow structure throughout the storage volume. Installation of the PAX water mixers will reduce use of the centrifugal pumps by 50%. In February 2014, the City installed a PAX water mixer in one of the tanks at the Hamilton Water Plant. Due to the operational success of the installed mixer, Pacific Gas and Electric Company (PG&E) recommended that the City install mixers in all of its water tanks in order to reduce energy use.
Environmental Services Department (ESD) staff and PG&E engineering staff conducted field testing and analysis of potential energy savings at three of t...
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