San Antonio Water System Brackish Water Desalination Program, Phase I – Texas

Untapped Resource

The San Antonio Water System (SAWS) has developed a program that will provide San Antonians with a new water source. The SAWS Brackish Groundwater Desalination Program is transforming brackish water from the Wilcox Aquifer in southern Bexar County, TX, into millions of gallons of drinkable water using reverse osmosis. The estimated $411 million program, which will ultimately consist of three phases, is part of the SAWS 2012 Water Management Plan, designed to meet the city’s water needs over the next 50 years while reducing dependence on the Edwards Aquifer. Brackish groundwater is a plentiful, previously untapped, local source of water that will help diversify San Antonio’s water supplies.

In March 2013, Parsons, with a 50/50 joint venture (JV) partner, was selected by SAWS to serve as the construction manager at-risk (CMAR) for the first phase of this critical brackish water desalination program. This $119 million CMAR contract included:

• Performing preconstruction phase services
• Drilling and fitting out four new production wells
• Fitting out eight existing production wells
• Drilling and fitting out one new injection well
• Fitting out and operating two existing injection wells
• Fitting out existing injection well
• Fitting out six monitoring wells
• Building raw water conveyance system
• Constructing all program components
• Constructing and operating reverse osmosis treatment plant for 3 months
• Constructing new administration building
• Constructing operational/control room with state-of-the-art SCADA system

The scope of work included 12 raw water production wells, raw and finished water conveyance, residual conveyance, a new deep injection well, a 12-MGD reverse osmosis membrane water treatment plant, a chemical treatment system, supervisory and data acquisition controls, and a new administration building that incorporates a public tour route, pilot plant, and training facility.

The first phase of the SAWS Brackish Groundwater Desalination Program—a huge leap forward in water independence for San Antonio—was completed on time and within budget and is the largest inland desalination plant in the United States. The new 12-MGD desalination plant officially opened in January 2017.

Featured Aug 2015/Updated Aug 2017