Volunteer Summer Study

The Guadalupe River is one of the highest rated recreational and scenic rivers in Texas and is Kerr County’s central asset.  The river provides water to the citizens for domestic, agricultural, municipal, and recreational purposes.  Therefore, maintaining excellent water quality is essential.  Water quality is determined by the amount of contaminants in the water; as contaminant levels increase, water quality decreases.  There are many types of potential contaminants originating from many sources.  The objective of this study was to determine the level of one specific contaminant, E. coli.

E. coli bacteria levels are commonly monitored to assess the quality of surface water because they are an indicator of water contamination.  E. coli originates in the intestines of warm-blooded animals and the presence of E. coli indicates that warm-blooded animal feces have reached the water and that other pathogens may be present.  Sources of E. coli can include inadequately treated sewage, livestock, pets, birds, and mammals.

Each summer, the Upper Guadalupe River Authority (UGRA) tests E. coli levels at popular swimming holes throughout Kerr County.  The results of this Swimability Study are compared to the Texas Commission on Environmental Quality’s (TCEQ) standards for contact recreation.  For a single grab sample, the standard for contact recreation set by TCEQ is 399 colonies of E. coli bacteria per 100 milliliters (mL).  If E. coli levels are greater than 399 colonies of bacteria per 100 mL, then there is a higher risk of contracting waterborne illness while swimming.

In 2004, UGRA began the Volunteer Summer Study Program to supplement data collected during the Swimability Study and to include interested members of the community in water quality testing.  The information collected by the volunteers also helps identify areas in need of further investigation. Working together, we can maintain the pristine nature of the Guadalupe River and protect our community’s most valuable natural resource.

Thank you to all the volunteers who helped make the 2024 Volunteer Summer Study happen. Below are the PDFs of the report booklet and the presentation with the results from the study. If you have any questions about the results or the volunteer program, let us know!

If you would like to be a part of the Volunteer Summer Study, please contact Matthew Wilkinson at (830) 896-5445 or mwilkinson@ugra.org.