FROM: Robert Thompson, General Manager
Originator: Mike Dorman, Director of Engineering
SUBJECT:
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HEADWORKS REHABILITATION AT PLANT NO. 1, PROJECT NO. P1-105
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GENERAL MANAGER'S RECOMMENDATION
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RECOMMENDATION: Recommend to the Board of Directors to:
Approve a contingency increase of $8,893,200 (4%) to the existing Construction Contract with Kiewit Infrastructure West Co. for Headworks Rehabilitation at Plant No. 1, Project No. P1-105, for a new total contingency of $17,786,400 (8%).
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BACKGROUND
The headworks process is where all incoming sewers enter the plant and preliminary treatment is performed. The existing headworks at the Orange County Sanitation District (OC San) have been in service for more than 30 years without a major rehabilitation effort.
OC San is executing the Headworks Rehabilitation Project to rehabilitate the existing systems, including the metering and diversion structure, bar screen building, bin loading building, influent pump station, grit basins, primary influent channels, and electrical power distribution and control systems. This project is also constructing new facilities that include a grit pump station, grit handling building, headworks odor control and chemical facility, a drainage lift station, electrical buildings, and other support systems.
Construction started in May 2021 and is expected to be completed by late 2028. The construction is approximately 65% complete.
When the construction contract was awarded in March 2021, staff proposed a lower than usual contingency for a rehabilitation project and planned to present a mid-construction review to the Board of Directors, highlighting the progress and risks encountered to date.
RELEVANT STANDARDS
* Ensure the public's money is wisely spent
* 24/7/365 treatment plant reliability
PROBLEM
The cost of change orders to the construction contract is nearing the Board-approved contingency amount. The changes to date have largely been re...
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