FROM: James D. Herberg, General Manager
Originator: Kathy Millea, Director of Engineering
SUBJECT:
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PRIMARY SEDIMENTATION BASINS NO. 6-31 RELIABILITY IMPROVEMENTS AT PLANT NO. 1, PROJECT NO. P1-133
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GENERAL MANAGER'S RECOMMENDATION
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RECOMMENDATION: Recommend to the Board of Directors to:
A. Receive and file Bid Tabulation and Recommendation for Primary Sedimentation Basins No. 6-31 Reliability Improvements at Plant No. 1, Project No. P1-133;
B. Award a Construction Contract to Shimmick Construction Company, Inc. for Primary Sedimentation Basins No. 6-31 Reliability Improvements at Plant No. 1, Project No. P1-133, for an amount not to exceed $6,275,000; and
C. Approve a contingency of $627,500 (10%).
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BACKGROUND
Primary treatment is the second step in the process at Orange County Sanitation District (OC San) Reclamation Plant No. 1. Primary treatment removes approximately 75% of the suspended solids from raw wastewater prior to the secondary treatment processes. Primary treatment occurs in structures referred to as primary clarifiers or primary sedimentation basins.
Plant No. 1 includes two sets of primary clarifiers; a set of 26 rectangular clarifiers and a much older set of three circular clarifiers. The circular clarifiers are nearing the end of their useful life and are scheduled to be replaced as part of a future project scheduled to start in 2026 and will take approximately five years to complete.
RELEVANT STANDARDS
* Comply with California Public Contract Code Section 20103.8, award construction contract to lowest responsive, responsible bidder
* 24/7/365 treatment plant reliability
PROBLEM
During replacement of the circular clarifiers, only the rectangular clarifiers will be available. During this time, the reliability of the rectangular clarifiers is paramount to maintain the required Level of Service.
The reliability of the rectangular clarifiers is currently limited by agin...
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