Memorandum

City of Lawrence

Utilities

TO:	David Corliss, City Manager Cynthia Boecker, Assistant City Manager Diane Stoddard, Assistant City Manager
FROM:	Mary Baker, Project Engineer, Utilities
CC:	Dave Wagner, Director of Utilities Philip Ciesielski, Assistant Director of Utilities Tim Will, Kaw Plant Maintenance Manager Beth Frailey Krishtalka, Management Analyst
Date:	November 20, 2007
RE:	Kaw Water Treatment Plant Building Envelope Repairs Change Order #1 - Utilities Project #1CP-206

Please include the following item on the consent agenda for the November 27, 2007 City Commission meeting.

Authorize the City Manager to amend the contract with Restoration & Waterproofing Contractors in the amount of $56,600.00 for additional work to secure the coping stones to the wall of the 1954 Chemical and Filter Building at the Kaw Water Treatment Plant and to seal the window openings according to revised design details. The new contract total will be $322,659.00.

Project History/Details:

The Chemical Filter Building at the Kaw Water Treatment Plant dates from 1954; its construction includes brick facing over concrete block. The exterior walls of the building have numerous cracks in the brick and cracks in the interior tiled corners. The west wall has deflected outward. Repairs to the Chemical Filter Building façade are being accomplished during Phase I of the project.

During construction, Restoration & Waterproofing Contractors found that the mortar between the parapet coping stones and the building had deteriorated. The stones are loose are being held in place by inertia.  They are not in danger of falling and creating a safety hazard.  The condition was not obvious during the study phase because the stones have neither rotated nor moved.

The Chemical Filter Building was built with a discontinuous façade. The first three vertical feet under the parapet is separated from the remainder of the wall by flashing (sealing material). Walter P. Moore, the consulting firm who designed the repairs, believes that differential movement between the two sections has also contributed to the west wall deflection and that an early sign of wall movement (a band of wide mortar joints) is present on the remaining walls of the Chemical Filter Building.

Walter P. Moore has designed a repair that both attaches the parapet coping stones to the building and pins together both vertical sections of the wall.  This design is within the intent of the project: removing the causes of building facade deterioration.

Restoration Waterproof Contractors submitted a proposal for $51,730.00 to complete the work.  The remaining value of the change order, $4,870.00, addresses removal of rubble and the installation of additional sealing material for window lintel renovation. The actual construction of the windows differs from the record drawings used to design the repairs.

Walter P. Moore and staff have evaluated the proposal and recommend performing the work.

Construction Schedule:  The anticipated project schedule is as follows:

Advertise for Bid       June 19, 2007

Bid Letting               July 17, 2007                     

End Construction       January 24^th, 2008  

The contractor is ahead of schedule and will likely complete the project in December 2007 if weather conditions continue to be favorable during the construction period.

Project Funding:  Funding for construction comes from the 2007 Utility Department Capital Improvement Project non-bonded construction fund. Including the cost of the change order, the project is still within budget and will be completed under the Engineer’s estimate.

Action Request:  The Utilities Department is seeking authorization from the City Commission for the City Manager to amend the contract with Restoration & Waterproofing Contractors in the amount of $56,600.00 for additional work to secure the coping stones to the wall of the 1954 Chemical and Filter Building at the Kaw Water Treatment Plant and to seal the window openings according to revised design details. The new contract total will be $322,659.00.