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HomeMy WebLinkAbout14 Roundhill Tank - Change Order AllowanceTRUCKEE DONNER Public Utility District MEETING DATE: August 3, 2022 TO: Board of Directors FROM: Neil Kaufman, Water System Engineer Chad Reed, Water Utility Director AGENDA ITEM #14 SUBJECT: Consideration of Additional Change Order Allowance for the Roundhill Tank Rehabilitation Project APPROVED BY Brian C. Wright, General Manager RECOMMENDATION: Authorize the General Manager to execute a contract amendment in the amount of $62,400 to the Round hill tank rehabilitation project, change order allowance, for a total not to exceed contract amount of $706,100. BACKGROUND: The District currently operates 34 water storage tanks located throughout the water distribution system: • Thirty ground level welded steel tanks • Two ground level bolted steel tanks • One partially buried pre -stressed concrete tank • One elevated welded steel tank The tanks range in volume from 100,000 gallons to 1.5 million gallons with the oldest tank constructed in 1963 and the newest tank constructed in 2005. The District evaluated adjustments to investments in capital maintenance required to extend the useful life of its inventory of water utility storage tanks during preparation of the 2020 Water System Capital Improvement Plan update. Through this process a staff determined the need to increase funding allocated to a more comprehensive tank maintenance program and subsequently budgeted. During the development of a 10-year tank maintenance plan, staff identified the benefits of an outside engineering consultant to analyze: Page 1 of 3 • Seismic Evaluation - Conduct a seismic evaluation of all of the ground level steel water tanks; identify potential solutions to minimize seismic risk for each tank; and prepare budget level cost estimates for these potential solutions. • Rehabilitation of Roundhill Tank — The Roundhill Tank was constructed in 1974. Based on the most recent inspections and maintenance history, it is judged to be the tank most in need of rehabilitation. The consultant would perform more detailed evaluations of the Roundhill Tank and then prepare a set of bid documents to rehabilitate the tank and upgrade it to current standards. In June 2021, the Water Department issued a Request for Proposals (RFP) to select a consultant to perform the engineering work. After review of the proposals, a contract was awarded to Carollo Engineers in August 2021. Bid documents for the rehabilitation of Roundhill Tank were completed in March 2022. The District began advertising for bids and the bid opening was held on April 20, 2022. Two bids were received. At the regular Board of Director Meeting held on May 4, 2022, a contract was awarded to Resource Development Company (RDC) of Sparks, Nevada. The Board of Directors approved on May 4, 2022 the construction contract for a total authorization not to exceed $643,700. ANALYSIS: Roundhill tank is currently undergoing a comprehensive rehabilitation, which begins by removing the interior and exterior coating systems. Once the coating systems are removed a much more detailed analysis of the existing welds and tank steel can be performed. After removing the tank coatings (interior and exterior) in the vicinity of the welds, it was determined that the tank wall materials and weld seems have been exposed to a much higher level of pitting and corrosion than previously anticipated. RDC's analysis points to a potential that the original tank fabricator did not sufficiently clean the steel at these areas after the welding operations before applying the original coatings. After discussions with RDC and Carollo Engineers, it was agreed that installing cover plates over the areas with significant metal loss would be the most cost effective approach to extend the useful life of the tank. These plates would be 10" wide and would cover the entire perimeter of the tank (both inside and outside) at the second horizontal seam and the adjoining vertical welds. In other areas of the tank where pitting has occurred 4" diameter cover plates will be installed on the interior only. RDC has provided a cost proposal of $62,400 for the labor and materials associated with this additional work. OBJECTIVES & GOALS: This item is in support of the following goals and objectives: District Code1.05.020 Objectives: Page 2 of 3 1. Responsibly serve the public. 3. Provide reliable and high quality water supply and distribution system to meet current and future needs 5. Manage the District in an environmentally sound manner 6. Manage the District in an effective, efficient and fiscally responsible manner. Strategic Goals: 1. Manage for Financial Stability and Resiliency FISCAL IMPACT: The cost proposal from RDC for the additional work is $62,400. The funding source for this additional work would be the Water Department Capital Reserve fund. As stated in the May 4, 2022 approved Board Meeting staff report: In the event that change orders are necessary for either project, those costs woula be covered from Water Department Capital Reserve Fund. The year-end 2021 balance of this fund was $ 1, 015, 747, budget year-end 2022 balance is $920, 000, and current forecast year-end 2022 balance (excluding this subject item) is $920, 000. Attachments: None Page 3 of 3