SAN ANTONIO – As concerns grow around wastewater treatment plants and water quality near the Edwards Aquifer, KSAT got a rare inside look at one of the region’s largest existing facilities.
The Salitrillo Wastewater Treatment Plant, operated by the San Antonio River Authority, handles the wastewater from about 33,000 people in northeast and eastern Bexar County.
The process starts with raw wastewater flowing into the facility.
“This is the beginning part of the treatment aspect, where raw wastewater is coming in” Travis Krueger, superintendent of plant operations for the San Antonio River Authority, said.
From there, wastewater is pumped through the facility.
“Each of these pumps will do 5,000 gallons a minute, 15,000 gallons a minute total max,” Krueger explained.
Officials said one of the most important parts of the process is something that may not look very appealing.
“This is the heart and soul of the process, is that fluid right there,” Krueger said. “It does look very nasty, but what it is, is a population of microorganisms.”
Those microorganisms play a major role in cleaning the water.
“The bacteria feed off of the organic compounds that are found in the wastewater, and so they break those compounds down, and they help break them down to clean it out,” Krueger said.
The microbes and wastewater are then sent into one of five aeration basins.
“All the microbes, along with the raw wastewater, are introduced into any one of the five aeration basins,” Krueger said. “And this is where everything is broken down.”
Once that process is complete, the water moves to final disinfection.
“After that, on the outside launder, the outside trough, all that water is ready for its final disinfection,” Krueger said.
Rather than chlorine, the plant uses ultraviolet light.
“This is where our final disinfection is happening,” Krueger said. “So we utilize ultraviolet light for the final disinfections versus alternative disinfections such as chlorine.”
After being disinfected, the treated water is discharged into Salitrillo Creek.
“This water discharges into the Salitrillo Creek that will eventually make its way to the Martinez Creek and then to the Cibolo Creek and eventually to the San Antonio River,” Krueger said.
Because of growing debate surrounding proposed wastewater treatment plants near the Edwards Aquifer recharge zone, KSAT asked how close this plant is to sensitive groundwater areas.
“We are a good distance away from the recharge zone. We don’t discharge close to it,” Krueger said. “Now this water does infiltrate groundwater sources though downstream, through the natural earth process. But none of it is done for a direct ground injection at all.”
Plant officials also said the water leaving the facility is often cleaner than some natural bodies of water.
“As it’s coming in, it’s getting polluted already because of the natural resource of, you know, you’ve got algae growth, fish, minnows, turtles, birds,” Krueger said. “What we’re discharging into it is a far better quality.”
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