Since 2011, public power utility provider New Braunfels Utilities has explored the feasibility of incorporating an aquifer storage and recovery, or ASR, system that would allow for a large underground water storage area that could be accessed during times of drought or emergency. “It doesn’t bring you any new supplies, but it gives you a water-management strategy,” said Fred Blumberg, engineer for Arcadis Design and Consultancy Team, has been working closely with NBU on the feasibility and logistics of the ASR. The $23 million project is part of NBU’s 5-year financial operating plan and would be funded by revenue.
State approval
According to NBU CEO Ian Taylor, the entity hopes to pump a mixture of water from its five blended ground and surface water sources to use in the ASR, but the initiative would need to receive the go-ahead from the Texas Legislature in order to move forward. Mark Friberg, executive director of external and regulatory affairs for the Edwards Aquifer Authority, said the clearance is needed because current regulations prohibit injecting outside sources of water into the aquifer. NBU’s ASR system would be the first to be located in the Edwards Aquifer, while there are three ASRs currently operating in other aquifers across Texas. Currently, NBU and the EAA are working together through an interlocal cooperative contract for the development and use of an ASR. “We have an agreement that lays out all the things they need to do from a monitoring standpoint to make sure there are no negative impacts on the Edwards [Aquifer] or the spring system,” Friberg said. NBU Chief Operating Officer Ryan Kelso said the utility provider will monitor the area to ensure the integrity of the aquifer is not compromised. The oversight will be completed by drilling monitor wells that will be positioned between the ASR site and the freshwater springs. “So if we start to see any communication into that monitor, well, that would be an indication that [water is] moving. We would have to alter operations,” Kelso said. Taylor said preserving the aquifer’s integrity will continue to be a top priority and stressed that NBU would not incorporate treated reusable water or wastewater into the ASR. “Ultimately, this ASR project is designed to make our water supply resilient, and that water supply includes the Edwards Aquifer, so we don’t want to do anything with an ASR project that may harm the aquifer we try to protect,” Taylor said.
Moving forward
The NBU and the EAA hope to see two ASR bills pass during the 2019 legislative session that will allow for the EAA to alter its regulations and allow for NBU’s project. The Texas House Natural Resources Committee that oversees water policy convened March 26 to hear testimony supporting House Bill 481. Senate Bill 520, which is sponsored by state Senator Donna Campbell, R-New Braunfels, and co-sponsored by state Senator Judith Zaffirini, D-Laredo, passed through a senate committee the following week. State Rep. John Kuempel, R-Seguin, filed HB 481. “It’s important,” he said to the committee. “It allows NBU to more efficiently manage its treated surface water and groundwater by storing excess drinking water when it is available.” Kelso said the bills will next move to the House and Senate floor before potentially receiving final approval from Texas Gov. Greg Abbott. “I don’t know if and when they may actually act on the bills,” Kelso said. “We’re pretty confident they’re going to vote on it here pretty soon, but you never know.” State Rep. Lyle Larson, R-San Antonio, the House committee chairperson, expressed a positive outlook on the emergence of more ASR systems in Texas, namely the New Braunfels project and another that is being pursued in Buda. “It’s encouraging to see the technology, and it’s starting to proliferate across the state because of evaporation, and people want to hold their drinking water,” Larson said.
How it works
The area where the water would be stored is referred to as the brackish portion of the aquifer where high salt levels become prevalent. Blumberg said the contrasting densities between the brackish and fresh water would allow for a barrier, creating a bubble that would hold pre-treated water. “One of the real benefits to ASR is the fact that you’re able to develop these projects in measured steps based on previous work leading up to what you’re about to do,” Blumberg said. “You’re taking these kind of stairstep decision points based on success at other decision points.” NBU’s planned ASR project would hold 14,000 acre-feet of water. For perspective, Kelso said to imagine 1 acre of land covered in water that is 1 foot deep. Once implemented, 7,000 acre-feet of water would blend into a mixing zone of clean and brackish water, while the remaining pretreated half would be accessible when needed. The numbers, Taylor said, were modeled after the amount of water that would be needed during a repeat of the drought of record, which occurred in the 1950s. According to Taylor, the approach is more economical than other areas that have stored water and treated it post-extraction through expensive water desalinization plants. “So we chose the option behind curtain No. 2, which is to leave half [of the water] in the ground,” Taylor said.
