MULTI-PARAMETER PROFILING IN A KARST SPRING INVESTIGATION: INSIGHTFUL, AFFORDABLE AND EASY

Karst systems are complex and dynamic due to diagenetic heterogeneity and temporal dynamics. These characteristics provide significant challenges to chemical investigations by requiring numerous samples in space and time. Multi-parameter profiling can offset these constraints while providing necessary detail for this dynamic complexity. An example of multi-parameter profiling is presented in a recent aquifer investigation at Salado Springs, central Texas. Salado Springs were integral to historic (Chisolm Trail) cattle drives and growth of the town. These springs discharge from the Northern Segment of the Balcones Fault Zone (BFZ) Edwards aquifer which supplies water to the community and surrounding countryside. Salado Springs are an important part of current aesthetic appeal and provide critical habitat for the Salado Salamander which recently was listed as “Threatened” by the U.S. Fish and Wildlife Service. Understanding interactions between groundwater and surface water surrounding Salado Springs is critical to managing the water quantity and quality necessary for both people and wildlife. Recent investigations at Salado Springs have included dye tracing, natural radon analyses and water chemistry. However, these techniques can be time consuming and expensive. The Salado Springs investigation also incorporated multi-parameter probes in longitudinal and cross-section profiling that provided new insights quickly and inexpensively. In addition to improving understanding of known discharge sites, new discharge sites were discovered in the critical habitat area using this technique. Data obtained by multi-parameter probes at Salado Springs were even more insightful when combined with flow and results from dye tracing and radon analysis. Multi-parameter probes have increased in quality, affordability and parameter diversity. They have great potential to aid in understanding complex and dynamic karst environments similar to Salado Springs.