Authorization to Solicit Requests for Proposal for the Rehabilitation of Sewer Manholes Throughout Culver City. City of Culver City California City Council Agenda Item Report Meeting Date: December 8 2008 AGENDA ITEM: Authorization to Solicit Requests for Proposal for the Rehabilitation of Sewer Manholes Throughout Culver City. Item Number: C 8 Contact Person/Dept.: Eric Mirzaian Public Works Public Works Fiscal Impact: Yes x No Phone Number: (310) 253 6410 General Fund: Yes No X Public Hearing: Public Notification: Master E Mail Notification List (12/03/08); Action Item: Attachments: X Department Approval: Charles D. Herbertson (11/25/08) Chief Financial Officer Approval: Jeff Muir (12/02/08) City Attorney Approval: Carol Schwab (by H. Baker) (12/02/08) City Manager Approval: Jerry B. Fulwood (12/02/08) RECOMMENDATION: Staff recommends the City Council authorize staff to release a Request for Proposals (RFP) for the rehabilitation of 27 sewer manholes throughout Culver City. BACKGROUND: Public Works Staff has identified 27 sewer manholes throughout the City in need of rehabilitation. The sewer manhole is the access way from the manhole lid on the surface of the street leading down to the sewer main. The rehabilitation will include the rehabilitation of existing concrete or brick sanitary sewer manholes to rebuild strength and eliminate possible infiltration inflow root intrusion and future deterioration of the concrete and brick due to the sewer environment. DISCUSSION: Sewer manholes deteriorate for a variety of reasons. The constant stress of traffic causes subsidence and shear cracks which progressively weaken these structures. Additionally disintegrated mortar joints become primary entry points for ground water infiltration washing out supporting back fill and causing manhole walls to collapse. Corrosive sewer gases found in sewer lines attack concrete walls deteriorating the concrete and causing structural failures. The combination of hydrogen sulfide and wate...
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