By Moses Leos III

The practice of injecting potable water into an existing aquifer for future use may be in Buda’s future after city leaders expressed their desire to conduct a feasibility study on Aquifer Storage and Recovery (ASR).

According to Buda Water Specialist Brian Lillibridge, ASR could be viable in Buda and could prove to be beneficial during times of drought.

“The fact so many municipalities are looking into it, it’s a testament to how viable (ASR) is,” Lillibridge said. “It’s a shot in the arm in terms of drought resiliency.”

According to Lillibridge, there has been a “growing interest” in ASR, which is done only during times when water is available.

He said on April 19 there are a “growing number” of ASR projects across the state, with many cities conducting Phase 1 feasibility studies. Lillibridge referenced the San Antonio Water System (SAWS), which has 29 ASR wells in place.

The concept behind ASR involves finding a suitable aquifer to place either groundwater or surface water in for future use. One way to accomplish the transfer is with a two well system, where one well pumps the supplying water, and another well deposits water in the aquifer.

According to Lillibridge, Buda could focus on a project that would inject Edwards Aquifer groundwater into the middle or lower Trinity Aquifer. The process could be done during the winter months, Lillibridge said, when there is less demand.

Lillibridge said the practice allows for drought resiliency, as Buda could deposit excess water into its “drought piggy bank.”

“If we can save it up and store it when we have some excess … when we get into a drought declaration, that storage would offset the amount of water reduced,” Lillibridge said.

According to Lillibridge, regulatory conservation programs, such as the Barton Springs Edwards Aquifer Conservation District (BSEACD), “sees the benefit” of allowing “large volume users to store Edwards water.”

But in order to find out if the storage process can work for the city, Buda must first conduct a feasibility study, which has a price tag of $40,000 to $100,000. Monies allocated for the Electro Purification project, which Buda is no longer a partner with, could fund the cost for the ASR study.

The estimate, according to Lillibridge, doesn’t include any well testing which is also necessary.

One issue is the cost of a well to be drilled into the Trinity, which could be anywhere from 900 to 1,100 feet in depth. The study would also conduct geological evaluation to assess how much water could be stored in the aquifer.

The study will also evaluate water quality interaction, especially with the possibility of injecting surface water.

Lillibridge said injecting dissimilar water, such as surface water into a groundwater aquifer, might require treatment for any potential quality issues.

Another factor could include state rules for stored water, where water must be treated for drinking quality standards. Lillibridge said efforts are underway to relax that language.

In addition, he said ASR isn’t the “silver bullet” to solve all of Buda’s future water needs. 

Buda Mayor Todd Ruge said the city is hoping to use shared data from the BSEACD and other privately owned wells to help prove the feasibility.

Should the project prove feasible, Ruge said the city could pay for it out of its water/wastewater utility fund or issue a Certificate of Obligation Bond. Buda could also allow voters to decide via a bond initiative.

It’s currently unknown how much ASR could cost the city.

But Ruge said conducting the feasibility study would give the city insight into whether the project is cost effective. Ruge said the city is “comfortable” with other water options, such as water delivered via the Hays Caldwell Public Utility Agency pipeline, but they want to look at “every option available.”

“We want to have every tool in our tool box when it comes to infrastructure, especially water,” Ruge said.