Plans for a water treatment plant in northwestern Bexar County have come under fire from environmental activists and residents. Renner Homes hopes to build 2,900 homes on about 1,160 acres. The Guajorote district should build its own Class A water treatment plant. The plant will dump one million gallons of treated wastewater into Herotes Creek each day.
Representatives of the Texas Environmental Quality Commission said at a recent hearing that they do not believe the released water poses any danger to humans or wildlife. SAWS has already given approval to a planned sewage treatment plant and will supply water to the development. But concerns remain.
TPR’s Jerry Clayton recently spoke with Dr. Ron Green, a groundwater hydrologist who worked on a two-year study on the potential impacts of wastewater in the Herotes Creek Basin before retiring from the Southwest Institute.
This conversation has been edited for length and clarity
CLAYTON: Tell us a little bit about the water that is discharged into the Herotes Creek basin. For example, is it safe to swim in?
green: Now, when these facilities are in operation, they are trying to achieve high standards of emissions. We may or may not achieve these standards. Even if they do, they introduce many nutrients into the environment, such as phosphorus and nitrogen. And they lead to deterioration of surface water due to the reduction of dissolved oxygen. And the nutrients make algae grow in the river.
It is not very attractive for swimming. It becomes less clear. Then it doesn’t smell so good. Dissolved oxygen leads to the extinction of animals and plants. Therefore, Herotes Creek will not look the same as it has seen in the past.
Clayton: So all the water that flows into Herotes Creek ends up in the Edwards Aquifer. is that correct?
CLAYTON: Should this be a concern for those pumping water from the Edwards Aquifer?
green: If, over time, recharge declines to the point that the Edwards Aquifer itself is less healthy, it will become a concern for all who depend on the Edwards Aquifer.
Clayton: So I understand that one of your big concerns is that this development could set a precedent. right?
green: If similar density developments are built in Northwest Bexar County and beyond, there is a danger of ever-increasing charges to the deteriorating Edwards. This is an open question by scientists. At what point does the Edwards Aquifer deplete to the point of being a health concern? Looking at San Antonio’s water system, it relies heavily on water from the Edwards Aquifer. However, the only treatment offered for Edwards River water is the addition of small amounts of chlorine and fluoride.
Therefore, when the recharge to the Edwards River drops to such an extent that the water needs to be treated, either a treatment plant should be installed at each well or well, or a centralized treatment plant should be installed. Either way, it would be a very expensive proposition.
CLAYTON: How permanent is the damage to the aquifer when these pollutants are introduced?
green: If these developments continue into the Edwards recharge and contribution zones, they may have permanent effects on the aquifer and may not be naturally cleared.
Full Disclosure: Jerry Clayton lives in the area affected by the planned water treatment plant.