FROM: James D. Herberg, General Manager
Originator: Kathy Millea, Director of Engineering
SUBJECT:
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DIGESTER FERRIC CHLORIDE PIPING REPLACEMENT AT PLANT NO. 1, PROJECT NO. P1-135
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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 Digester Ferric Chloride Piping Replacement at Plant No. 1, Project No. P1-135;
B. Award a Construction Contract to Performance Plumbing & Mechanical Inc., dba PPM Contracting, for Digester Ferric Chloride Piping Replacement at Plant No. 1 for a total amount not to exceed $515,000; and
C. Approve a contingency of $51,500 (10%).
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BACKGROUND
Digester gas produced by digestion of wastewater sludge in anaerobic digesters contains mostly methane and carbon dioxide, but also hydrogen sulfide that must be limited in concentration to comply with South Coast Air Quality Management District permit conditions associated with the Central Generation co-generation facility. These facilities supply approximately two-thirds of the Orange County Sanitation District's (Sanitation District) power requirements.
Ferric chloride is added to anaerobic digesters to reduce the hydrogen sulfide concentration in the digester gas. To do this, small diameter piping is routed through utility tunnels from an existing digester ferric chloride facility to Anaerobic Digesters 7 through 16.
RELEVANT STANDARDS
* Comply with environmental permit requirements
* Comply with California Public Contract Code Section 20103.8, award construction contract to the lowest responsible bidder
PROBLEM
The existing digester ferric chloride piping is failing and has required repairs in numerous locations due to age and partial blockage.
PROPOSED SOLUTION
Award a Construction Contract for Digester Ferric Chloride Piping Replacement at Plant No. 1, Project No. P1-135. This contract will replace the deteriorated digeste...
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