Memorandum
City of Lawrence
Utilities
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TO: |
David Corliss, City Manager |
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FROM: |
Mary Baker, Project Engineer, Utilities |
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CC: |
Dave Wagner, Director of Utilities Philip Ciesielski, Assistant Director of Utilities |
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Date: |
October 2, 2007 |
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RE: |
Stoneridge Elevated Water Storage Tank Project Status |
Summary: The Stoneridge Elevated Water Storage Tank Project is currently in the design phase. We anticipate bid letting in early December and construction completion in June 2009.
Background: The City owns property at 5600 W. 6th Street (6th Street and Stoneridge Drive) intended as a site for the construction of an elevated water storage tank. The 2003 Water Master Plan identified the West Hills Service Area as requiring additional storage volume to meet future water demands.
Additional water storage volume provided by the new tank will increase the reliability of water supply in the West Hills Service Area, ensure capacity for peak demands for future growth, and provide water storage for fire suppression. Based on the recommendations in the 2003 Water Master Plan and additional system evaluations the construction of a 1.5 million gallon tank was recommended to provide additional distribution system storage and reduce pressure fluctuations during periods of peak demand.
Tank Style and materials: Elevated storage tanks sized from 1 million gallons to 4 million gallons are considered large tanks by industry standards. Large tanks are commonly constructed with closed pedestals as opposed to being supported by multiple legs like the City’s Stratford Elevated Tank. One benefit of constructing a closed pedestal tank is that the interior base of the tank may be finished and used for other purposes. The City intends to construct the future Kanawaka North booster pumping station within the tank base.
Closed pedestal tanks may be constructed entirely of steel, or a combination of a steel bowl and a concrete base (a composite tank). Either type of tank is suitable for the site. During the evaluation of tank sizing the two elevated tank construction styles were evaluated for construction, operation and maintenance costs. Based on recent bid histories of tanks in the proposed size range and the potential long term maintenance and painting costs, the composite concrete column style of construction was selected for the City’s elevated tank. See the attached renderings of the proposed tank.
Accommodation for Future Antennas: At this time the project is providing underground conduit for telecommunications cable, tank penetrations, cable support racks, and a support rail for future installation of cellular communication antennas. The cost of constructing these additional features will be evaluated in terms of the project budget with the receipt of the construction bids.
Project Timeline:
December 2006: City Commission approved execution of the contract and the City entered into a contract with Black & Veatch Corporation for engineering services related to design and construction of a new storage tank.
February 2007: Project staff confirmed that composite tank material was suitable for the site and likely to result in less expensive construction and ongoing maintenance costs without impact to the construction schedule.
April 2007: Black & Veatch completed hydraulic modeling in order to establish the tank overflow elevation.
May 2007: Black & Veatch submitted the Design Memorandum to KDHE for review and submitted Notice of Proposed Construction to FAA.
June 2007: Black & Veatch began developing construction documents for the project.
July 2007: Consultants and staff conducted a public information meeting and finalized the plat and site plan.
August 2007: City reviews 60% construction drawings and specifications.
September 2007: City receives 90% construction drawings and specifications.
October 2007: Black & Veatch finalizes bidding documents.
We anticipate the following schedule for the remainder of the project:
November 2007: Advertise for Bids
December 2007: Award construction contract.
June 2009: Complete construction.
Budget: Black & Veatch has completed an estimate of probable cost for construction. The capital cost estimate includes 10% construction contingency. The following is an estimate of total project cost:
Capital Cost: $3,193,500
Engineering Contract: $216,835 (already encumbered 2006)
Construction Phase Engineering: $5000
Inspection Services Fee: $125,000
Total Project Cost: $3,540,335
Public Meeting: A public meeting was held on July 12, 2007. Although approximately 40 adjacent property owners were notified by mail, and additional notifications were posted on the City’s web site attendance was limited to staff, the consultant and members of the media.