Environment Texas Research & Policy Center
With our state’s warm weather for most of the year, Texans have unparalleled opportunities to get outdoors and enjoy our many creeks, streams and lakes. Taking a dip in a cool swimming hole on a hot summer day is a defining experience for many people in the state.
But pollution continues to plague many Texas waterways, putting the health of Texans at risk. An investigation by Environment Texas’ Research and Policy Center found that some popular Texas freshwater swimming spots exceeded state or federal health standards at least once in 2010. Furthermore, our research found that the state of Texas’s health standards, testing systems, and public notification protocols are inadequate to properly protect human health, while polluted swimming holes often go unreported to the public, who may continue to swim in unsafe waters.
E. coli is one of the most prolific pollutants found in Texas’ freshwaters and is used as an indicator organism for other pollutants. The EPA takes a risk-based approach to E. coli counts in order to best safeguard public health and the environment. Their criterion for E. coli in a single sample of water is 235 mpn/100mL, a standard that allows for illness in about 8-10 out of 1,000 swimmers. However, the Texas Commission on Environmental Quality, or TCEQ, uses a standard of 394mpn of colonies/100mL, raising the exposure rate to potential illness.
Fortunately, many of Texas’ most popular swimming holes, including Hunts Crossing, Brinks Crossing, Bull Creek at District Park, Lake Marble Falls, Lake Travis, Pedernales Falls, Ladybird Lake, and Risien Park all consistently tested well below Texas and EPA standards for E. coli pollution in 2010. Unfortunately, Bull Creek near Loop 360 failed both the Texas and EPA standards, and other sites such as Barton Springs, Hamilton Pool, Stillhouse Hollow, and the Slab on the Llano River tested above EPA standards in 8% or more of samples. Disconcertingly, about 50% of sites selected for the study did not have a sufficient number of samples in 2010 and 2011 on record to provide significant data.
• Bull Creek at Loop 360 exceeded TX Standards in 35% of tests and EPA Standards in 47% of tests between 2010 and 2011.
• “The Slab” on the Llano River exceeded EPA and Texas standards in 8% of samples 2010-2011.
• Stillhouse Hollow exceeded EPA and Texas standards in 19% of samples in 2010-2011.
• Bull Creek above 2222 and Lake Austin regularly showed very high samples in 2010-2011, but were not tested sufficiently to produce meaningful data.
The frequency of testing varies widely between monitoring agencies. Whereas the Lower Colorado River Authority consistently tests its waters six times a year, additional monthly testing by volunteers at some sites is prone to neglect. Other agencies test less frequently depending on the availability of volunteers and the vulnerability of the site, and some popular swimming holes in Texas are never tested. Furthermore, testing data from freshwater swimming areas is not easily accessible to the public, especially when compared to the successful Texas Beach Watch program.
Texas Beach Watch, managed by the Texas General Land Office, collects water samples at 167 sites along the Texas coast. They contract with universities, local governments and commercial labs to ensure that competent testers sample all sites once a week from May through September and twice a week during the off-season of October through April, a system that ensures consistent and regular sampling. All test results are entered into a database that is easily accessible to the public online. These results are used by local authorities to issue public warnings, beach closings, and in longitudinal studies, and Texas Beach Watch ensures that sites with high bacterial levels are tested every 24 hours until levels return to a safe range. Meanwhile, the San Marcos-based Texas Stream Team organizes and trains water monitor volunteers to test surface waters around the state once a month. Texas Stream Team posts testing results on their Dataviewer, where the public can access test results from their favorite swimming sites.
Not all of Texas’ freshwater sites are as frequently or regularly tested, however, nor are test results put to use to ensure public safety. More than half of the samples in the study did not have accessible reports showing more than 10 separate tests between 2010 and 2011, the minimum required for analyzable data. The exemplary Texas Beach Watch and Texas Stream Team programs should be used as a model for Texas’ freshwater bacteria testing, since they provide consistent, regular sampling whose results are easily accessible to the public and are used to promote safe swimming through public warnings and closures.
The state of Texas should work to better protect the health and our environment by:
• Adopting the federal E. coli standard of 235 mpn/100mL for a single sample and 126mpn/100mL for a geometric mean.
• Abandoning plans to allow higher levels of E. coli in secondary or no-contact waterways.
• Ensuring that freshwater sites are tested bi-weekly or weekly by competent monitors.
• Maintaining and promoting an accessible public database with testing data and health advisories.
• Posting signage at polluted freshwater swimming areas, and closing swimming areas when necessary.
• Reducing the amount of pollution that enters waterways through solutions like stronger storm water controls.