Aquifer district explores wastewater reuse to save on groundwater

The Barton Springs-Edwards Aquifer Conservation District is investigating the idea of letting two of its largest commercial permit holders replace water they’re drawing from the aquifer with treated wastewater.

 

Texas Lehigh Cement Company and Centex Materials, both located in Buda, have been talking with the Buda city officials about the possibility of using some of the city’s treated wastewater for the companies’ commercial uses, which include the repression of dust (required by federal air quality regulations) from stone mining and crushing operations.

 

In a meeting last month, the district board of directors directed staff to work with the companies and the Buda officials to find out if the wastewater can be used without contaminating the aquifer, from which about 50,000 people draw their drinking water. Board members are particularly concerned with Centex because part of the company’s property sits directly about the aquifer’s recharge zone.

 

At Thursday’s board meeting, John Dupnik, senior regulatory specialist, reported on meetings between the involved parties and presented new mapping of the Centex property. He said that staff members are, with Centex’s permission, planning to bore holes in the ground so that they can better determine the location of a fault line that separates the aquifer recharge zone (where water runoff flows directly into streams that feed the aquifer) from the transition zone (where the runoff would be less likely to impact the aquifer). With that knowledge, CenTex could create barriers that would direct runoff of the recycled wastewater away from the recharge zone.

 

Finding out exactly where the fault runs would “help us with a level of comfort in terms of wastewater affluent application,” Dupnik told the district’s board of directors.

 

BSEACD General Manager Kirk Holland warned that the staff’s efforts are not to be interpreted as a recommendation. “We’re not advocating anything at this point,” he said. “We’re just exploring what the possibilities are.”

 

For board members, the proposal presents a mixed bag. On the one hand, the reuse of wastewater would wean two large commercial water users off of the Edwards Aquifer. On the other hand, the wastewater runoff could potentially degrade the aquifer’s pristine water quality.

 

“I think it’s the board’s consensus – I’m certain that it is – that we would like to explore this for water conservation and reuse,” said board member Craig Smith, “provided it’s safe.”

 

Nevertheless, the district’s efforts may all be irrelevant. While Centex representatives have expressed a willingness to work with the district, Dupnik said, they have also told him that if the board fails to approve their proposal, the company will go over their heads and seek a permit from the Texas Commission on Environmental Quality.