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Item # 9.

Council Meeting (Updated)

Meeting Date:	08/25/2020
Department:	Airport
Pillars:	Excellence in Asset Management Excellence in Transportation Systems
Milestones:	Establish an intentional culture throughout the organization that is based on continuous improvement, excellence, and adherence to our core values

AGENDA CAPTION:

Present, Discuss, and Consider Action on a Change Order to the Contract with McMahon Construction, LP for Reconstruction of George Haddaway Drive and Associated Pavements at Addison Airport to Include Reconstruction of the Landside Entry to the Fuel Farm From Addison Road and to Authorize the City Manager to Execute the Agreement in an Amount Not to Exceed $99,074.26.

BACKGROUND:

The purpose of this item is to approve a change order to the contract with McMahon Construction, LP for reconstruction of George Haddaway Drive and associated pavements west and south of the fuel farm at Addison Airport. The change order includes three parts: (1) standard reconciliation of quantities of completed items within the current contract; (2) addressing unanticipated fence modifications that were made in the current construction project to address safety (removal of barbed wire) and maintenance (addition of concrete mow strip) concerns; and (3) extending reconstruction limits to include the landside fuel farm entrance area between the Addison Road right-of-way, the relocated Gate 3 on George Haddaway Drive, and the landside entry gate to the fuel farm that is used by fuel delivery tankers.

McMahon Construction, LP was awarded the bid for the George Haddaway Drive reconstruction work at the May 26, 2020 Council meeting. The bid for this project was split into a base bid plus two alternates. The base bid was for reconstruction of George Haddaway Drive itself from the airside of the fuel farm to the vehicle service road located just east of Taxiway Alpha. Alternate 1 was for reconstruction of failed pavements west and south of the fuel farm, used by on-airport refueler trucks to turn around. Alternate 2 was for reconstruction of a short section of Gerorge Haddaway Drive from the new location of Gate 3 to just east of the entry gate serving the EHOAA hangar complex. McMahon was awarded the base bid plus alternate 1 at a bid price of $652,824.90. While McMahon's bid price of $41,488.08 for the alternate 2 work was well within the total construction budget of $753,000 for this project, airport staff, in consultation with the project engineers (Garver), did not recommend awarding the alternate 2 work because the design was for a stop-gap improvement that did not address the larger fuel farm entry area. Airport staff instead requested Garver to design pavement reconstruction and storm water drainage for the entire entrance area -- which was serviceable but showing signs of distress and pavement failures -- in anticipation of addressing this area in a future project, as airport staff did not expect that the current project construction budget would be sufficient to accomplish this additional work.

Garver, working under the FY2020 On-Call Services contract they have with Addison Airport, redesigned the entire entry area from the Addison Road right-of-way to the airport and fuel farm entry gates. The redesign addressed drainage issues that were not addressed in the original alternate 2 design. The redesigned entry area includes 785 square yards of new 10-inch concrete pavement, compared with 268 square yards of 10-inch concrete contemplated in the original alternate 2 scope. The unit pricing in McMahon Contracting, LP's bid is very favorable. It has been confirmed that McMahon Contracting will honor the unit pricing in their bid should this change order be approved, which makes it possible to reconstruct the entire fuel farm entry area while remaining within the original construction budget of $753,000.

The proposed change order represents a good value for Addison Airport. Having the work performed now under a change order will save the Airport the costs of bidding and contractor mobilization if the work were to be performed under a separate, future contract. Furthermore, the change order honors very favorable unit pricing that was part of McMahon Contracting's original bid. The proposal was also reviewed with Addison's Director of Public Works, who concurred that this proposed change order represents a good value for the airport. With the original bid award of $652,824.90 plus the proposed change order amount of $99,074.26 the total project cost ($751,899.16) will remain within the original construction budget of $753,000.

RECOMMENDATION:

Administration recommends approval.

Attachments
Presentation - George Haddaway Change Order 1
Change Order #1 with Memo
Original Recommendation of Bid Award
Specifications and Contract Documents
George Haddaway - Original Plans
George Haddaway - Change Order 1 Plans