The Ballroom
Over the Aquifer?
RECEIVED Tue., April 19, 2005
Dear Editor,
In reference to the “Naked City Headlines" and Rachel Proctor May’s p.29 article [“AMD Plans to Move Over Edwards Aquifer,” News, April 15] on the proposed AMD facility near Oak Hill, I am compelled to clarify the claim that the site is “… over the Edwards Aquifer.” According to the geologic map published by the Bureau of Economic Geology, UT Austin, the proposed site does not overlie the Edwards Formation. The site is located to the west of the Mount Bonnell fault and on the outcrop of the older Glen Rose Formation. Here, the Edwards was eroded away long ago (along with the intervening Comanche Peak and Walnut Formations), exposing the underlying Glen Rose, which is not recognized as a significant local aquifer. Additionally, the excellent satellite image of the Barton Creek area on the SOS Web site shows that the proposed site is fairly remote to Barton Creek. As shown on that image, the existing developments of Barton Creek golf course and the Lost Creek subdivision would seem to pose a more significant element of runoff contamination, since they are far larger and lie directly on the banks of Barton Creek. Examination of the topographic map (published by the United States Geologic Survey) of the proposed site indicates that the bulk of the drainage at the proposed site is southward into the Williamson Creek Watershed, not Barton Creek. In these regards, the proposed site would appear to be fairly sensibly located. I offer this information not in support of development nor in opposition to it, but as a scientist concerned at the lack of accuracy in your and others' reporting of the issue. I suggest that you and SOS review the maps and your stated position(s) in this light.
In reference to the “Naked City Headlines" and Rachel Proctor May’s p.29 article [“AMD Plans to Move Over Edwards Aquifer,” News, April 15] on the proposed AMD facility near Oak Hill, I am compelled to clarify the claim that the site is “… over the Edwards Aquifer.” According to the geologic map published by the Bureau of Economic Geology, UT Austin, the proposed site does not overlie the Edwards Formation. The site is located to the west of the Mount Bonnell fault and on the outcrop of the older Glen Rose Formation. Here, the Edwards was eroded away long ago (along with the intervening Comanche Peak and Walnut Formations), exposing the underlying Glen Rose, which is not recognized as a significant local aquifer. Additionally, the excellent satellite image of the Barton Creek area on the SOS Web site shows that the proposed site is fairly remote to Barton Creek. As shown on that image, the existing developments of Barton Creek golf course and the Lost Creek subdivision would seem to pose a more significant element of runoff contamination, since they are far larger and lie directly on the banks of Barton Creek. Examination of the topographic map (published by the United States Geologic Survey) of the proposed site indicates that the bulk of the drainage at the proposed site is southward into the Williamson Creek Watershed, not Barton Creek. In these regards, the proposed site would appear to be fairly sensibly located. I offer this information not in support of development nor in opposition to it, but as a scientist concerned at the lack of accuracy in your and others' reporting of the issue. I suggest that you and SOS review the maps and your stated position(s) in this light.
Douglas B. Watkins
Exploration geologist
Exploration geologist
[Rachel Proctor May responds: Point taken on "over the aquifer"; the proper term for the proposed AMD site, which is in the contributing zone, would be "in the Barton Springs Watershed." However, even if runoff from the site doesn't drain directly into Barton Creek, water in Williamson Creek ends up in the aquifer when that creek crosses the recharge zone.]
