REPORT TO COUNCIL
SUBJECT
Title
Authorization to Amend an Existing Contract for Design of a Sodium Hypochlorite Disinfection System for the Water Pollution Control Plant (F14-75)
Report
REPORT IN BRIEF
Approval is requested to amend an existing contract with HDR Engineering, Inc. (HDR) of Walnut Creek for design services associated with a new sodium hypochlorite disinfection system at the Water Pollution Control Plant (WPCP). The amendment will increase the total value of the contract by $75,000, from $360,180 to $435,180. The recommended increase includes $67,663 for additional design services and $7,337 for additional engineering services during construction. The added services are for operational improvements to the disinfection system, recommended as the result of preliminary studies conducted as part of the initial contract award.
ENVIRONMENTAL REVIEW
This amendment to an existing design contract is not a project as defined in Section 15378 of the California Environmental Quality Act (CEQA).
BACKGROUND AND DISCUSSION
The final treatment process at the WPCP currently disinfects waste water using gaseous chlorine and then neutralizes the chlorine with bi-sulfate prior to Bay discharge. The recycled water production process also uses gaseous chlorine for disinfection and residual chlorine. Gaseous chlorine has been used at the WPCP for decades and was historically the disinfectant of choice due to its effectiveness and low cost. However, gaseous chlorine is a very dangerous chemical and as a result many treatment plants are eliminating its use in favor of liquid chlorine (technically sodium hypochlorite or bleach). This product is much less dangerous and therefore reduces the potential hazards to plant workers and the surrounding community.
An initial design scope to convert the plant disinfection system from gas to liquid chlorine was awarded to HDR on February 26, 2013 (RTC No. 13-048). A portion of the work scope included prelimi...
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