STRATEGIC PRIORITY: Transportation & Infrastructure
AGENDA DATE: December 14, 2022
COUNCIL DISTRICT(S): 10
DEPARTMENT: Water Utilities Department
EXECUTIVE: Kimberly Bizor Tolbert
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SUBJECT
Title
Authorize an increase in the construction services contract with John Burns Construction Company of Texas, Inc., for the emergency repair of two parallel 48-inch diameter wastewater siphons just upstream of Cottonwood Creek - Not to exceed $1,626,806.00, from $13,756,649.00 to $15,383,455.00 - Financing: Wastewater Construction Fund
Body
BACKGROUND
On August 28, 2019, City Council authorized a construction services contract with John Burns Construction Company of Texas, Inc. for the installation of water and wastewater mains at 14 locations by Resolution No. 19-1286. While investigating an odor complaint, Dallas Water Utilities (DWU) discovered a pipe failure and small sink hole in the Cottonwood Creek area near 11550 Forest Central Drive. During the site visit it was determined that the top of one of the two 48-inch diameter siphon pipes that cross Cottonwood Creek had failed, resulting in a cave-in and sink hole over the failure location.
In response, staff worked with a consulting engineer to assess methods to repair the siphon barrel and determined an open cut replacement of both 48-inch siphon barrels (50-100 feet on each pipe) is needed to address the failure. Due to the extent and difficulty of repair and the extensive bypass required to maintain wastewater service during the work, DWU determined a repair of the pipe is not within in-house capabilities. DWU approached two construction contractors, and only one was able to assist due to construction complexities. John Burns Construction Company submitted a final repair cost estimate of $1,626,806 with supporting information on September 28, 2022. The estimate was reviewed and found to be a reasonable cost for the significance and difficulty...
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