From his rolling Hill Country spread, Wes Pitts can watch changes in gray-green Onion Creek as it riffles by. This is the same creek that twice in 2015 flooded poor neighborhoods in Southeast Austin, but here, miles upstream, on a windy, dry late January day, it wends amiably. From beneath the oaks, pecans and elms that line the banks, Pitts can catch perch, bass and crawfish. In some calmer spots, the water is still and clear; in others, whitewater dribbles over gravel and around small limestone boulders.
But Pitts, a 50-year-old insurance broker, and his neighbors worry that a proposed expansion of a sewage treatment plant several miles upstream might foul their pristine waterway.
The city of Dripping Springs, looking to attract businesses and manage growth, is asking the state environmental agency for permission to discharge as much 995,000 gallons of treated effluent per day into a tributary of Onion Creek.
Pitts and his neighbors, including Realtor Gary Keller of the firm Keller Williams, are teaming up to try to thwart the wastewater expansion. They have launched a website. Keller paid for a study looking at alternative options — and he has hired lawyers, including David Braun, a prominent Hill Country land conservation attorney, to examine ways they might protest the Dripping Springs plan.
They could be joined by the city of Austin, whose watershed protection officials say that nutrients from the treated sewage water could lead to algae blooms in the creek. Because the creek ultimately feeds the Barton Springs portion of the Edwards Aquifer, they say that same treated water could eventually make its way to the iconic pool.
The Dripping Springs wastewater treatment plant, built to replace antiquated septic systems, has the capacity to treat 313,500 gallons per day and currently treats about 70,000 gallons per day.
But the city is growing fast. Its population has increased from about 1,500 residents in 2000 to nearly 2,100 in 2014, according to Census Bureau figures. Roughly 30,000 people live in the wider community around the city.
If a treatment plant expansion, which could cost roughly $30 million, is approved by the state environmental agency, the plant could be the second to have a permit to discharge cleaned-up wastewater into a Hill Country creek that eventually feeds the Barton Springs portion of the Edwards Aquifer. (Belterra, a Dripping Springs-area subdivision, has another such permit.) Other communities, including Buda and Wimberley, have considered similar moves as they grapple with growth. The population of Hays County could increase nearly threefold by 2060, according to estimates in the state water plan.
Bypassing the creek?
Dripping Springs officials began considering a plant expansion after the city’s economic development committee, led by former state Rep. Patrick Rose, who runs a title company in town, declared in a letter to the mayor that the lack of capacity undermines the city’s ability to meet the needs of existing residents, manage new growth and “recruit additional, quality primary employers to our community.”
An engineering firm hired by the city concluded that by 2023 the plant will have to treat nearly 200,000 gallons per day.
Currently, Dripping Springs uses treated wastewater to irrigate city-owned land.
While the city expects to spray treated wastewater on city-owned playing fields and land at new subdivisions springing up in the area, it is seeking permission from the state to discharge into an Onion Creek tributary. The direct discharge permit would give the plant another option for handling cleaned-up sewer water in case it outstrips the demand to irrigate neighboring lands.
“The ultimate goal is not to have any water in that creek,” Dripping Springs Mayor Todd Purcell said. “And if it has to go in the creek, we’re committed to make sure it’s treated to the highest level and keeps that creek clean.”
Under state standards, the effluent should be clean enough to fish or swim in. Still, U.S. Geological Survey monitoring stations suggest the creek is dry about 10 percent of the time, opening up the prospect that the creek could be chiefly composed of effluent during drought.
“There are rules in place, but it’s not healthy for a creek that sometimes runs dry or shallow,” said Kasey Mock, who is director of the farm and ranch division of Keller Williams and who has been working on the Onion Creek issue with Gary Keller.
Keller’s feasibility study for wastewater alternatives included something called direct potable reuse, in which treated sewage could be directly piped back to a water treatment plant, bypassing the creek altogether. Dripping Springs in January approved a nonbinding letter of intent with the Dripping Springs Water Supply Corp. to negotiate on such a system, which could cost about $9 million in capital costs and might handle about 500,000 gallons a day of the treated wastewater.
“Our goal in this effort is to see Onion Creek remain a healthy pristine watershed, and to protect the property values of the downstream landowners,” Mock said.
Barton Springs concerns
If roughly half as much effluent as Dripping Springs could potentially discharge were sent into Onion Creek, “it would have a measurable adverse impact” as far as 11 miles downstream, said city of Austin environmental scientist Chris Herrington, with the creek going from a waterway that rarely sees algae to one that would have a high likelihood of it — algae can suck up the water and block light from penetrating the surface, making the creek less hospitable for other plants and fish.
Austin earlier joined a challenge against the Belterra permit.
That move angered state Rep. Jason Isaac, R-Dripping Springs, who lives in the subdivision and last session proposed a measure that would have made it harder for cities to challenge wastewater treatment plans by other municipalities. He said the cost of such challenges are borne by the communities proposing the plants.
“It’s hypocritical if Austin wants to protest a wastewater discharge (permit),” Isaac told the American-Statesman, pointing out that Austin, upriver of Bastrop, discharges effluent into the Colorado River.
Austin officials have said discharging into the Colorado River, engorged with water as a consequence of a series of major dams, doesn’t compare with the potential for discharge into Hill Country creeks.
The Isaac bill passed out of the House but floundered in a Senate committee.
Dripping Springs officials say that providing wastewater services to the subdivisions gives the city some leverage in managing development, such as requiring construction setbacks from area waterways.
The wastewater plant replaced a hodgepodge of septic systems, which presented their own groundwater problems. And if the city forgoes a plant expansion, the region could open itself up to a host of decentralized, smaller wastewater plants, said the mayor.
“This is very important to me personally,” said Purcell, who noted that the creek runs through his parents’ property.