Memorandum

City of Lawrence

Utilities Department

TO:	David L. Corliss – City Manager Cynthia Wagner - Assistant City Manager Diane Stoddard - Assistant City Manager
FROM:	John Shutak – Utilities Engineer
CC:	Dave Wagner – Director of Utilities Philip Ciesielski – Asst. Director of Utilities Mike Lawless – Asst. Director of Utilities Beth Frailey Krishtalka – Assistant to Director Mark Hegeman – Utilities Operations Superintendent Dave King – Utilities Maintenance Superintendent
Date:	April 11, 2012
RE:	April 17, 2012 Agenda Item – Approve Change Order No. 2 for priority group II of Project UT0919CS General Wastewater Pumping Station Improvements.

Please include the following item on the City Commission Agenda for consideration at the April 17, 2012 meeting:

Authorize the City Manager to execute Change Order No. 2 to the construction contract with Wildcat Construction Co. Inc for priority group II of Project UT0919CS General Wastewater Pumping Station Improvements increasing the contract amount by $31,478.48 and extending the contract time by 32 calendar days.

Project Description:

The Department of Utilities budgets a yearly fund for the ongoing maintenance, repair, and, when necessary, replacement of existing wastewater pumping stations within the collection system.

Project Details:

The Department of Utilities operates a number of small (80 to 300 gpm) vac-prime wastewater lift stations to convey sewage to its wastewater treatment plant. These lift stations were installed by the development community to provide service to localized areas of development. The lift stations are typically located in utility easements adjacent to or surrounded by residential property. The existing stations are 15 to 40 years old, many have exceeded their useful lives, are unsafe to maintain as several of the lift stations are classified as confined space entry, many are no longer supported by the original manufacturer and require replacement to bring them up to current KDHE minimum design standards.

The general intent of the project is to replace a number of the existing vac-prime lift stations with rail-mounted submersible pumps, valve vault, overflow prevention, backup power connection and flow metering in order to meet current KDHE minimum design standards. Some modifications to the existing gravity lines upstream of each station may be required. The Department of Utilities will provide wet well level instrumentation, programmable logic controllers and programming. The vac-prime lift stations included in Priority Group II of the General Wastewater Pumping Station Improvements are identified on the attached map.

Project Status:

To date the contractor, Wildcat Construction Co. Inc., has completed the rehabilitation of pump stations 12 and 27 and will be proceeding to the final pump station identified in priority group II, pump station 22.

Utility Department records, provided to the engineering consultant during the design phase of the project, indicated that the existing wetwell for PS22 was six (6) feet in diameter. Existing surface mounted equipment platform dimensions and other visual indicators were used to confirm the record diameter of six (6) feet during the design phase of the project. Pumping equipment, access hatches, and other appurtenant equipment were designed to fit and operate based on a wetwell diameter of six (6) feet. During field verification activities by the contractor, it was found that the existing wetwell is four (4) feet in diameter. The existing four-foot diameter wetwell will not accommodate the required equipment or permit the pump station to perform at the operational levels established during the design phase of the project thus necessitating its replacement with a six-foot diameter wetwell. Other costs associated with the wetwell replacement at PS22 include costs for geotechnical investigation at PS22 to determine the soil profile, compaction and foundation requirements, and groundwater levels to the full depth of the excavation required to replace the wetwell. Additional contract time of 32 days has been requested, and is supported by City staff, to account for the fabrication, curing, delivery, and installation of the six-foot diameter precast wetwell as well as the additional time required for full removal of the existing structure.

Change Order No. 2 also includes additional costs associated with the installation of City supplied step down transformers at PS12, PS22, and PS27 as well as additional depth required for the installed precast manhole section at PS27.

Construction Contract Costs:

	Cost	Days
Original Contract	$624,700.00	150
Change Order 1	$0.00	60
Change Order 2	$31,478.48	32
Current Contract Total	$656,175.48	242

To date change order adjustments represent 5.0% of the original contract amount.

Project Funding:

These projects will be funded out of the 2009 Department of Utilities bonded construction fund per resolution No. 6835. A total allocation of $2,846,000.00 has been identified for completion of the design and construction of the General Wastewater Pumping Station Improvements, Project UT0919CS, through the bond resolution. The 2009 Bond proceeds are from the Build America Bonds. Per the terms of the Bond these funds must be expended prior to August of 2012 to maintain their non-taxable status.

Action Request:

Thank you for your assistance. Please advise if you have any questions.