FROM: James D. Herberg, General Manager
Originator: Rob Thompson, Assistant General Manager
SUBJECT:
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DIGESTER CLEANING AND DISPOSAL CONTRACT
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GENERAL MANAGER'S RECOMMENDATION
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RECOMMENDATION:
A. Approve a Service Contract for Digester Cleaning and Disposal with American Process Group, Inc., per Specification No. S-2020-1165BD, for a total amount not to exceed $4,636,674 per year, for the period of November 1, 2020 through October 31, 2025, with four optional one-year renewals; and
B. Approve an annual contingency of $463,667 (10%).
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BACKGROUND
Digesters stabilize organic solids from primary and secondary treatment processes and produce biosolids and digester gas to fuel the Orange County Sanitation District's (Sanitation District) Central Generation facilities. The Sanitation District periodically cleans the digesters to remove undigestible materials that build up over time. This material can build-up and limit process capacity and inhibit the digester's performance. After cleaning, the Sanitation District assesses the structural and mechanical conditions inside of the digesters. More frequent minor repairs inside the digesters prevent larger scale, more costly damage.
RELEVANT STANDARDS
* Maintain a proactive asset management program
* Safe, beneficial reuse of Biosolids
* Maintain a culture of improving efficiency to reduce the cost to provide the current service level or standard
PROBLEM
Without periodic digester cleaning to remove undigestible materials, the digester's process capacity and performance are compromised. Additionally, it is necessary to clean the Sanitation District's holding digesters more frequently to protect the newly installed centrifuges from damaging debris which can accumulate and pass through. Finally, the Sanitation District will not have the opportunity to properly assess the structural and mechanical conditions inside the digesters.
PROPOSED SOLUTION
Staff recom...
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