NewsDrop July 2023

PARTNERSHIPS

Figure 1.

By : Jennifer Adkins Schudrowitz, EAA Aquifer Science Research Supervisor

AQUIFER STORAGE AND RECOVERY PROGRAM A S R

Aquifer Storage and Recovery, known as ASR, involves the treatment and injection of clean water into a suitable aquifer for temporary storage and subsequent recovery. ASR is generally used to store water during times when rainfall is plentiful, and then the stored water is used during drought. New Braunfels Utilities (NBU) is evaluating ASR (NBU-ASR) in the brackish portion of the Edwards Aquifer. The NBU-ASR Project area is located near the New Braunfels regional airport in Guadalupe County, approximately 5.8 miles east–southeast of Comal Springs (Figure 1) . NBU is targeting a total storage volume that it estimates would be sufficient for use during a severe Edwards Aquifer drought. The NBU-ASR also includes a volume of water to form a “buffer zone” which, ideally, works to prevent the migration of stored injection water during recovery and keeps the surrounding native brackish water out of the recovered water (Figure 2) .

In 2017, the EAA and NBU entered into an Interlocal Cooperative Contract (ICC) authorizing NBU to recharge, store, and recover water from the ASR pending results of a phased investigation demonstrating both the continued feasibility of the project and no unacceptable impacts to Comal Springs flow or Edwards Aquifer freshwater quality. The ICC promotes an effective cooperative approach, and it clearly defines the roles and responsibilities of the operator (NBU) and regulator (EAA) with respect to monitoring and mitigation of potential adverse effects from the ASR. The NBU-ASR project is a multi-phase project. Phase I (the Preliminary Work Phase) was conducted over a period of almost three years and involved efforts to collect detailed information concerning the hydrogeologic suitability of the target storage horizon(s) and to further characterize the brackish portion of the aquifer. Phase I was completed in August 2020. Phase II (the Demonstration Well Phase) involves the permitting, design, construction, and cycle testing of NBU’s demonstration well (ASR-D1) and the design, construction, and observation of up to three additional monitoring wells.

NBU Groundbreaking Ceremony.

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