FROM: Robert Thompson, General Manager
Originator: Mike Dorman, Director of Engineering
SUBJECT:
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ACTIVATED SLUDGE CLARIFIER ENTRY IMPROVEMENTS AT PLANT NO. 2, PROJECT NO. FR2-0023
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GENERAL MANAGER'S RECOMMENDATION
recommendation
RECOMMENDATION:
A. Receive and file Bid Tabulation and Recommendation for Activated Sludge Clarifier Entry Improvements at Plant No. 2, Project No. FR2-0023;
B. Award a Construction Contract to Tharsos Inc. for Activated Sludge Clarifier Entry Improvements at Plant No. 2, Project No. FR2-0023, for a total amount not to exceed $1,171,000; and
C. Approve a contingency of $117,100 (10%).
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BACKGROUND
The Activated Sludge facility at Orange County Sanitation District (OC San) Plant No. 2 has 12 rectangular clarifiers that are a key part of the biological secondary treatment process. The four Dissolved Air Flotation Thickeners (DAFTs) at Plant No. 2 thicken the collected sludge for further biosolid treatment. Both the secondary clarifiers and DAFT facilities are comprised of deep basins to facilitate the treatment process. To conduct maintenance and repair on the facilities, plant personnel either descend into the drained basins or complete the work from above using existing platforms or other supporting equipment.
RELEVANT STANDARDS
* Comply with California Public Contract Code Section 20103.8, award construction contract to lowest responsive, responsible bidder
* Provide a safe and collegial workplace
PROBLEM
The current placement of the davit crane and ladder at the 12 secondary clarifier basins forces plant personnel to maneuver around the davit crane when mounting and dismounting the ladder. The maneuvering difficulty can cause staff to slip and fall when trying to reach the ladder. Another safety concern is the improper use of the guardrails as the ladder holder, which were not designed for this use. Plant personnel also struggle ergonomically when lowering small equipment into th...
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