DEPARTMENT: Aviation
DEPARTMENT HEAD: Russell J. Handy
COUNCIL DISTRICTS IMPACTED: Citywide
SUBJECT:
Change Order for Terminal Area Taxiways Improvements, Package 3
SUMMARY:
This Ordinance approves a change order in the amount of $374,953.60 and authorizes payment to SpawGlass Civil Construction, Inc. (SpawGlass) for the Terminal Area Taxiway Improvements, Package 3 project at the San Antonio International Airport to replace an existing storm drain structure which was discovered to be undersized and not aircraft-rated once construction began. The new, larger structure will accommodate the proposed pipe size and ensure system capacity is met while meeting all current Federal Aviation Administration safety standards for items within the safety area. Funding is available from the Terminal Area Taxiways project and will increase the contract value to $23,009,288.74.
BACKGROUND INFORMATION:
The City regularly coordinates with the Federal Aviation Administration (FAA) for continued Airport Improvement Program (AIP) funding for eligible projects at the San Antonio International Airport. AIP funding eligibility is based on the Airport’s preliminary submittal of its annual Airport Capital Improvement Plan (ACIP) to the FAA. These projects may be eligible for grant funding at 75% of eligible project costs with a 25% local matching share. AIP funding available to the Airport for the airfield projects is a combination of entitlement dollars which are based upon the annual enplanements and discretionary dollars which are offered on a competitive basis to airports and are subject to available funding in any given year. The construction for the projects are packaged and phased in order to maximize potential FAA grant money the City would be eligible to receive each year and minimize impacts to airline and airport operations.
In June 2015, City Council authorized the submittal and acceptance of funds from an FAA Improvement Program for a total anticipated project estimated amount of $24,129,504.00 based on the 95% design documents with an anticipated grant amount of $18,097,128.00.
Construction Contract
In December 2015, City Council authorized a construction contract with SpawGlass for Terminal Area Taxiways Package 3 in the amount of $22,534,937.97 through Ordinance 2015-12-10-1043. The scope of the third package of construction projects includes the reconstruction of Taxiway N southwest from Taxiway G to just beyond Runway 4/22. Taxiway N reconstruction will additionally shift the taxiway centerline 50 feet to the southeast (toward Runway 4/22), reconstruct and construct new connector taxiways to Runway 4/22 and construct several connector taxiways to the Terminal A apron to improve aircraft operations in and around the terminal area while incorporating new design standards.
Proposed Change Order
When SpawGlass uncovered the existing storm drain structure just east of the intersection of Taxiway N and Taxiway G, it was discovered the existing pipe had reduced in size from a diameter of 42 inches to 30 inches just before the junction box and was located at a lower elevation than the planned 42-inch reinforced concrete pipe. The unanticipated pipe size and location meant the existing storm drain manhole would not accommodate the proposed pipe size, limit the capacity of the overall system and cause ponding during major storm events. In addition, the existing storm drain structure was not aircraft rated.
Kimley-Horn, the design engineer, determined that a new structure is required and recommended the removal of the existing structure with a new precast storm drain structure. The change order would also include the construction of two concrete pipe collars that would revise the alignment of the rubber gasket reinforced concrete pipe and connect the new pipes and existing pipes to the new precast storm drain structure.
The following table illustrates the change orders that have occurred since construction of this project began:
|
Item |
Amount |
|
Original contract value |
$22,534,979.97 |
|
Previously authorized change orders |
$99,397.17 |
|
Proposed change order |
$374,953.60 |
|
Revised contract value |
$23,009,288.74 |
ISSUE:
City Council authorization is required for change orders in the amount over $100,000.00.
ALTERNATIVES:
City Council could elect not to approve this change order. However, this change order was initiated due to unforeseen conditions and will allow construction to continue with storm water drain structures that can provide capacity to the overall system.
FISCAL IMPACT:
This action will authorize a change order in the amount of $374,953.60 to increase the contract amount to $23,009,288.74 and utilize previously-appropriated funding in the project from FAA AIP grant and Airport Improvement and Contingency funding and is included in the FY 2018-2023 Capital Improvement Plan Budget.
RECOMMENDATION:
Staff recommends authorizing the change order with SpawGlass for the Terminal Area Taxiways, Package 3 project at the San Antonio International Airport.