FROM: James D. Herberg, General Manager
Originator: Kathy Millea, Director of Engineering
SUBJECT:
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SUNFLOWER AND RED HILL INTERCEPTOR REPAIR, PROJECT NO. 7-66
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GENERAL MANAGER'S RECOMMENDATION
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RECOMMENDATION:
A. Approve a Professional Design Services Agreement with GHD Inc. to provide engineering services for Sunflower and Red Hill Interceptor Repair, Project No. 7-66, for an amount not to exceed $308,712; and
B. Approve a contingency of $30,871 (10%).
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BACKGROUND
The Orange County Sanitation District (Sanitation District) completed construction of the Sunflower Interceptor Reach 3 and Red Hill Interceptor Reach 4 and 5, Project No. 7-6-3 in 1971, ranging in size from 27 inches to 84 inches in diameter. The concrete pipe includes PVC lining on the upper 270-degrees of the pipe section to protect the concrete from corrosive sewer gas. PVC lining was not installed on the bottom 90 degrees because it was expected to be covered by the liquid in the pipe, which is not corrosive to concrete.
RELEVANT STANDARDS
* Protect Orange County Sanitation District assets
PROBLEM
In 2015, as part of the Sanitation District asset management program, the pipe between Red Hill Avenue at MacArthur Boulevard in Irvine and Sunflower Avenue at South Timber Street in Costa Mesa was assessed for internal corrosion and lining condition. This section also includes three siphons, but it was only possible to enter and assess one of the three siphons.
The Sanitation District's assessment indicated the PVC lining has failed at multiple locations and concrete below the 270-degree lining has corroded.
The services of a design consultant are needed to complete this project.
PROPOSED SOLUTION
Approve a Professional Design Services Agreement with GHD Inc.
TIMING CONCERNS
The concrete pipe continues to corrode until a construction project is designed and completed.
RAMIFICATIONS OF NOT TAKING ACTION
Increased risk of failure of...
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