Hays County Edwards Aquifer dye tests Published: May 24, 2008 04:22
Hays dye tests Aquifer water watch follows the flow under the county By Anita Miller News Editor Scientists injected non-toxic dyes into portions of the Edwards Aquifer recently in order to better understand the movement of water in the vast underground reservoir. The project is a collaboration between the Edwards Aquifer Authority (EAA), the Barton Springs Edwards Aquifer Groundwater Conservation District, the cities of Austin and Kyle, Texas State University, Aquarena Center and other area well owners. The intent is to “get a better idea of where the water comes from and recharges” before it re-emerges through springs, said Dr. Glen Longley, director of Texas State’s Edwards Aquifer Research Center. Such dye tracing is nothing new. Longley said it’s been going on for several years, but this latest round “is a new aspect of the project focusing more on the northern area” of the aquifer that gets recharge from the Blanco River. Though it has been the subject of intense study for years, questions still persist about the origin of water that flows from San Marcos Springs, and Longley said slight differences in the water temperature in different springs point to some of the water coming from local recharge through the Blanco and some coming from a regional recharge pool in the San Antonio portion of the aquifer. He said the temperature difference is slight, maybe one degree Celsius, between springs near the old Aquarena Hotel (now the Texas Rivers Center) and “deep spring” which is located nearer the lake’s fountains. According to EAA spokesman Roland Ruiz, the dye will be injected into three sinkholes in the Blanco River basin, after which scientists will monitor San Marcos and Barton Springs “over several weeks” as the dyes emerge. “The dyes used in this testing are safe for human consumption, but are not likely to be detectable in local water supplies” as a result of the study. “It’s going to shed more light on the understanding of the movement of water to the springs. It needs to be done, it’s a good thing,” Longley said. Longley, who is heavily involved in the aquifer Recovery Implementation Project (RIP) said the source of San Marcos Springs water is one of the issues that process is studying. “It’s all very important because the folks in San Antonio would like to have different requirements for their triggers on their wells than the San Marcos spring flow. They like to think it’s more locally influenced here but that’s just not the case.” He said he believes more local springflow comes from the regional pool. “Evidence given to the (RIP) committee at this point doesn’t change my mind, the fact that the majority of the water comes into the springs from the San Antonio area. They need to have triggers on their use of water that would help protect the spring flow here.” Ruiz said the tracer studies are “part of (the EAA’s) ongoing region-wide study of the Edwards Aquifer. Such studies contribute to the general understanding of the aquifer system and how to best manage and protect it as a water source.” http://www.sanmarcosrecord.com/local/local_story_145162202.html
