Tonight, the public is invited to give its input at a hearing held by the Texas Commission on Environmental Quality (TCEQ) over a permit to allow Dripping Springs to dump almost a million gallons of treated wastewater into Onion Creek, about a day upstream of Austin. That idea has many people in Austin very worried.

Chris Herrington is an environmental engineer for the City of Austin. He says Onion Creek does a lot of good for the region. It has some of the best water quality in Central Texas. It supplies water to the Trinity and Edwards aquifers. And, from there, it feeds one of Austin’s most iconic water features.

“More water in Barton Springs is from Onion Creek than any other individual source,” Herrington said.

Austin officials hope the TCEQ does not issue the permit to dump treated effluent into the creek. So, why would Dripping Springs want it? Some of it goes back to state law, says Ginger Faught, a deputy city administrator with the City of Dripping Springs.

She says the city actually plans to re-use much most of this water. But, the way state law is written, it needs a plan B, in case the water can’t be re-used. In this case, Faught says the only affordable alternative is the creek.

“The re-use component gets lost," Faught said. "This is something that we’re very committed to doing."

Herrington doesn’t believe the creek needs to be the plan B. He supports the re-use idea, but says Dripping Springs is under no real obligation to re-use water under the current proposal.

So, Austin would like to see some kind of agreement where water re-use is assured, what Herrington calls a "a trust but verify situation."

Finally, the two sides disagree on what environmental impact this dumping could have. Dripping Springs' Faught says doing this kind of thing is actually pretty common.

“Correct, and the state of Texas Commission on Environmental quality has agreed with us as well,” she said. “The state has determined that it will not adversely impact the existing uses in Onion Creek”

But, the City of Austin used water testing analysis created by the EPA to show that there could be a lasting impact.

“We’ve gone and we’ve done monitoring and we’ve used better science to inform our decision-making,” said Harrington. “Because we certainly don’t take these decisions lightly.”

The meeting tonight is the last time the TCEQ will hear public comment before deciding how to proceed.

It’s will be held tonight in Dripping Springs Ranch Park at 7 p.m. in the Special Events Venue Room located at 1042 Event Center Drive in Dripping Springs.