FROM: Robert Thompson, General Manager
Originator: Mike Dorman, Director of Engineering
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TPAD DIGESTER FACILITY AT PLANT NO. 2, PROJECT NO. P2-128
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GENERAL MANAGER'S RECOMMENDATION
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RECOMMENDATION:
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BACKGROUND
Sludge is a byproduct of wastewater treatment that requires further processing to reduce pathogens and volatile organic content so the remaining biosolids material can be beneficially reused in compliance with state and federal requirements. Orange County Sanitation District (OC San) uses anaerobic digesters at both Plants to stabilize sludge prior to dewatering. Anaerobic digesters are large, enclosed concrete structures that require pumping, mixing, heating, and gas handling systems. Anaerobic digesters also generate methane gas used to produce power and heat.
OC San has 18 digesters at Plant No. 2 that were built from 1959 through 1979. Completed in 2017, a comprehensive Biosolids Master Plan recommended upgrading the existing digester complex by adding Temperature Phased Anaerobic Digestion (TPAD) facilities.
TPAD Digester Facility at Plant No. 2, Project No. P2-128, is the first of four sequential projects planned to ultimately replace the entire digester complex as detailed in the Biosolids Master Plan.
Staff will present an update on the Project and decisions used to control costs and regulatory risks.
RELEVANT STANDARDS
• 24/7/365 treatment plant reliability
• Safe, beneficial reuse of Biosolids
• Use all practical and effective means for resource recovery
• Maintain and adhere to appropriate internal planning documents (Biosolids Master Plan and Strategic Plan)
ATTACHMENT
The following attachment(s) may be viewed on-line at the OC San website (www.ocsan.gov) with the complete agenda package:
• Presentation