CMAR Delivery Boosts Water Supply Amid Scarcity in Texas

OCTOBER 2016 – The year 2014 marked one of the worst droughts in Texas history, driving the City of Abilene, Texas, to initiate the PK Second Stage Drought Strategy project to develop available water sources.

Stage One of the City’s plan, the Hamby Water Reclamation Facility and Indirect Reuse project, was completed in 2015 providing much needed relief to the area. The raw water augmentation from the Hamby project only offset 25 percent of the daily water demands, which was not enough to counteract the historic drought.

Enprotec / Hibbs & Todd, Inc. (eHT) was tasked to develop the design for improvements to use brackish raw water from Possum Kingdom Lake and desalinate the raw water to a sufficient level to match current raw water quality from Hubbard Creek Reservoir. The City’s goals required upgrading the existing Possum Kingdom Lake intake pump station, owned by the Brazos River Authority, installation of 42 miles of raw water, product water and concentrate pipelines, and a raw water roughing facility (RWRF) designed to desalinate raw water prior to final conventional water treatment.

With the City’s objective to start using Possum Kingdom Lake water no later than the summer of 2015, eHT determined Construction Manager at Risk (CMAR) delivery would be vital in meeting the project’s aggressive schedule. Garney was selected as the CMAR through a value-based selection process in late 2014 and worked with eHT to fast-track the schedule. This included purchasing long lead materials and developing subcontracted scopes while final design was underway. Features of this critical project included:

RAW WATER PIPELINE: 48,890 LF of 36-inch C303 bar wrapped pipe, 565 LF of 48-inch steel cased bores, two connections to existing facilities, blow-off and ARV appurtenances

PRODUCT WATER PIPELINE: 36,730 LF of 36-inch C303 bar wrapped pipe, 3,374 LF of 36-inch HDPE horizontal directional drill (HDD), 804 LF of 48-inch steel cased bores, four connections to existing facilities, blow-off and ARV appurtenances

CONCENTRATE PIPELINE: 70,332 LF of 12-inch PVC pipe, 13,300 LF of 14-inch HDPE, 45 HDDs, outfall structure, and ARV appurtenances

Construction of the 36-inch raw water and product water pipelines was completed in November 2015 allowing the transfer of water to the City of Abilene. Today, the City continues to take a leadership role within the region by exploring opportunities with eHT and Garney to conserve available water supply. With water security becoming a growing issue in West Texas, the City remains diligent in determining solutions to provide additional water now, and for future generations to come.

“The City of Abilene is proud to have implemented a second stage short-term drought response strategy that included 30 miles of raw water, product water and concentrate pipelines along with the construction of a Raw Water Roughing Facility designed to partially desalinate raw PK water prior to being sent to Abilene for final, conventional water treatment,” said Tommy O’Brien, Executive Water Utilities Director for the City of Abilene. “Critical challenges that were successfully met include fast-track design and construction of a Reverse Osmosis system.”