Plans for a water treatment plant in northwest Bexar County have come under fire from environmentalists and residents. Lennar Homes wants to build 2900 homes on about 1160 acres. The Guajolote subdivision would be required to build its own Class-A water treatment plant. The plant would dump as much as one million gallons of treated wastewater per day into Helotes Creek.
A Texas Commission on Environmental Quality representative said during a recent hearing that the agency did not believe the discharged water would pose any risk to humans or wildlife. SAWS has already given approval to the proposed wastewater treatment plant and will provide water for the development. But concerns persist.
TPR's Jerry Clayton recently spoke with Dr. Ron Green, a groundwater hydrologist who worked on a two year study about the potential effects of wastewater in the Helotes Creek watershed before he retired from Southwest Research Institute.
This conversation has been edited for length and clarity
Clayton: Talk to me a bit about the water that would be discharged into the Helotes Creek watershed. Would it be safe, say to swim in?
Green: Well, when these facilities are operating, they try to attain a high standard of discharge. Sometimes they achieve those standards, sometimes they don't. And even if they do, they are going to introduce a lot of nutrients into the environment like phosphorus and nitrogen. And those lead to a degradation of surface water from reducing the dissolved oxygen. And then the nutrients lead to a growth of algae in the streams.
That's not going to be very appealing to swimming. It's going to not be clear. That's going to not smell very good. The dissolved oxygen is going to lead to the extinction of flora and fauna. So it's not going to be similar to the way Helotes Creek has been viewed in the past.
Clayton: So all of the water that goes into her Helotes Creek eventually ends up into the Edwards Aquifer. Is that correct?
Green: That's correct.
Clayton: Should this be concerning to anyone who's getting water from the Edwards Aquifer?
Green: If over time the recharge becomes degraded to such a degree that the health of the Edwards Aquifer itself is degraded, then that would be a concern to everyone who relies on the Edwards Aquifer.
Clayton: So I understand that one of your big concerns is the precedent this development might set. Right?
Green: If developments of similar density are built in northwest Bexar County and beyond, then you run the risk of more and more recharge to the Edwards being degraded. This is an open question by scientists. At what point will the recharge be degraded that the Edwards Aquifer is degraded to become a health concern? If you look at the San Antonio water system, it relies heavily on water from the Edwards Aquifer. But the only treatment that water from the Edwards is provided is a little bit of addition of chlorine and fluoride.
And so if you start degrading the recharge to the Edwards to such a degree that that water has to be treated, then you're going to either have to install treatment facilities at each well or well field or have a centralized treatment facility. In either case, that would be a very expensive proposition.
Clayton: How permanent is damage to an aquifer once those contaminates have been introduced?
Green: If these developments continue into the recharge and contributing zone of the Edwards, they are going to be likely to be permanent impacts on the aquifer that will not clean up by themselves.
Full disclosure: Jerry Clayton lives in an area that would be affected by the proposed water treatment plant.
