CITY COUNCIL AGENDA ITEM
ACTION REQUESTED:
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Approve the award of Cooperative Procurement 22-134, West-Southwest Waterworks 8.0 MG Ground Storage Reservoir Rehabilitation, to Garland/DBS for an amount not to exceed $312,861, plus a 5% contingency
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DEPARTMENT: Water Utilities
SUBMITTED BY: Darrell Blenniss, Director
BOARD/COMMISSION REVIEW:
N/A
BACKGROUND:
In 1996, the West-Southwest Waterworks (WSWWW) 8.0-million-gallon (MG) Ground Storage Reservoir was built as part of the WSWWW site that includes a 0.75 MG elevated water storage tank, high lift pumps, and an emergency backup electric power generator, as well as disinfection equipment, instrumentation, supervisory control and data acquisition (SCADA), system controls, and communications equipment. The reservoir was last washed, repaired, and coated in 2017.
In May 2021, Dixon Engineering, an independent third-party engineering firm, conducted an inspection of the reservoir that revealed deterioration of the exterior surface coating consisting of topcoat delamination and coating failures on the sidewall and roof, as well as accumulated grime and mildew.
DISCUSSION:
Based on the 2021 inspection, as well as concern for aesthetics, staff determined the reservoir exterior needed to be cleaned to the bare concrete, repaired, and coated to protect it from weathering. Garland DBS further determined that the existing topcoat is losing adhesion, as the original basecoat is unable to support the existing topcoat or additional coats. Garland DBS recommends vapor blasting to reach bare concrete to establish a solid base for coating adhesion direct to the reservoir surface. Vapor blasting and coating has a life expectancy of 10 years, whereas conventional power washing and recoating may only last five years.
Staff recommends the entire exterior of the WSWWW Reservoir be vapor blasted to bare concrete and coated to protect from weathering and maintain its aesthetics. It is imperative that the integrity of th...
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