HomeMy WebLinkAbout15 Airport Tank Rehab Closeout AGENDA ITEM 15
Public Utility District
MEETING DATE: October 5, 2022
TO: Board of Directors
FROM: Neil Kaufman, Water System Engineer
Chad Reed, Water Utility Director
SUBJECT: Closeout of the Airport Storage Tank Rehabilitation Project
APPROVED BY
Brian C. Wright, General Manager
RECOMMENDATION:
Adopt Resolution 2022-19 accepting the Airport Storage Tank Rehabilitation project as
complete and authorize the filing of the Notice of Completion.
BACKGROUND:
The Airport Tank is a 500,000 gallon partially buried pre-stressed concrete tank that was
constructed in 1980. During the summer of 2010, DN Tanks performed repairs to the
dome ring of the Airport Tank under an emergency declaration. The dome ring is located
where the vertical walls and roof join together and is critical to supporting the roof structure.
The work was completed on-time and with no change orders.
In 2010, it was noted that the tank was experiencing concrete spalling from the roof on
both the interior and exterior surfaces. However, this issue was not considered critical to
the structural integrity of the tank at that time and was not included in the scope of work
under the emergency. Over the last ten years, Water Department staff have periodically
applied concrete patches to the roof.
Based on inspections performed in the fall of 2020 and summer of 2021, it was determined
that the Airport Tank required substantive repairs to the roof system along with
replacement of many of the interior steel components such as the access ladder and
overflow structure.
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Contract documents were prepared for this rehabilitation work and bidding began in
October 2021. The bid opening was held on November 17, 2021. One bid was received.
The bid was from DN Tanks in an amount of$348,000. On December 1, 2021, the Board
awarded the construction contract for the Airport Storage Tank Rehabilitation project to DN
Tanks. The Board also established a $35,000 change order allowance for a total
authorization of $383,000.
ANALYSIS
DN Tanks began work in April 2022. In late May 2022, the work on the interior of the tank
was completed and the Airport Well was placed back into service. DN continued to work
on the tank exterior through June. During this time, it was determined that damage to the
roof exterior was more extensive than originally anticipated. Potential repair options were
discussed and District staff agreed to an amount of $28,276.71 to perform the additional
roof repairs.
During the punch list inspection in June, there were a few areas where water was seeping
through the tank wall. This issue was discussed with DN. DN had performed epoxy
injection at a number of locations to address similar seeping. It was DN's position that
additional time was needed to allow for the chemical reactions to continue, which would
stop the seepage. It was agreed to visit the issue later in the year.
In late August, the District sent photographs to DN identifying locations where the seepage
was still occurring. In early September, DN performed additional epoxy injection on the
exterior tank wall. At this time, there is no observable seepage through the tank wall and
the project is considered complete.
Goals and Objectives:
This item is in support of the following goals and objectives:
District Code1.05.020 Objectives:
1. Responsibly serve the public
3. Provide reliable and high quality water supply and distribution system to meet
current and future needs.
6. Manage the District in an effective, efficient and fiscally responsible manner.
Strategic Goals:
1. Manage for Financial Stability and Resiliency.
FISCAL IMPACT:
The original bid price was $348,000. The Board also established a $35,000 change order
allowance for a total authorization of $383,000. As outlined below, the final contract
amount is $376,276.71 .
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Item Amount
Original bid price $348,000.00
Approved change order requests $28,276.71
Total $376,276.71
In addition to the amount paid to DN Tanks, the District has incurred additional outside
expenses for construction inspection on this project of $17,125.
ATTACHMENTS:
Resolution 2022-19
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