FROM: Robert Thompson, General Manager
Originator: Mike Dorman, Director of Engineering
SUBJECT:
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OCEAN OUTFALLS REHABILITATION, PROJECT NO. J-137
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GENERAL MANAGER'S RECOMMENDATION
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RECOMMENDATION: Recommend to the Board of Directors to:
A. Approve a project budget increase of $10,500,000 for Ocean Outfalls Rehabilitation, Project No. J-137, for a new total project budget of $110,500,000;
B. Award a Progressive Design-Build Contract with Aqueos Corporation to provide Phase 1 progressive design-build services for Ocean Outfalls Rehabilitation, Project No. J-137, for an amount not to exceed $16,130,000; and
C. Approve an upper limit for this Contract of $94,193,000, which includes contingency.
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BACKGROUND
The Orange County Sanitation District (OC San) either reclaims treated wastewater (known as secondary effluent) from Plant No. 1 and Plant No. 2 through the Groundwater Replenishment System or discharges it to the ocean. Ocean discharge normally occurs through the Long Outfall. The Short Outfall is used during peak wet weather flows that exceed the Long Outfall capacity, during maintenance of the Long Outfall, or in the event of an emergency.
The Short Outfall was constructed in 1954, and extends approximately 7,000 feet offshore with a maximum depth of 65 feet. The Short Outfall has a capacity of 230 million gallons per day (MGD) and includes a 1,000-foot-long diffuser section that disperses treated wastewater into the ocean and ends with a flap gate structure. Effluents flows through the Short Outfall need to be chlorinated and dechlorinated.
The Long Outfall was constructed in 1971 with a capacity of 480 MGD. The main barrel of the pipeline is 21,400 feet long with a maximum depth of 200 feet, followed by a 6,000-foot diffuser section, for a total length of 27,400 feet. When the Long Outfall was put into service, the Short Outfall was placed into standby service.
The outfall system is a v...
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