By: Mike Clifford, NoDrippingSewage Campaign Organizer
and Raymond Slade, Jr., Certified Professional Hydrologist
July 16, 2018
On July 2, 2018, the Texas Commission on Environmental Quality (TCEQ) released their investigation report in response to local resident complaints of excessive algae in the South Fork of the San Gabriel River. TCEQ found multiple water quality violations by the Liberty Hill Wastewater Treatment Plant, which currently discharges 1.2 million gallons per day of treated wastewater into the river. The plant violations include discharges of sewage into the river. The summary below discusses the TCEQ report and the impacts of the effluent discharges on the river, due to the Liberty Hill plant violations, as well as their normal day-to-day operations.
TCEQ Violations Summary
The Liberty Hill plant received multiple violation notices from TCEQ in the July 2 report, including:
• Failure to prevent the unauthorized discharge of wastewater sludge (sewage) into the river
• Failure to properly operate and maintain the facility
• Failure to collect composite effluent samples for CBOD5, TSS, NH3-N, Nitrate-Nitrogen, Total Nitrogen, and Total Phosphorous, as required by the wastewater permit.
• Failure to obtain authorization to discharge storm water into the river
• Failure to properly notify the TCEQ of the Phase II plant completion
• Failure to provide a permanent access to the discharge site
The discharge of sewage probably represents the most alarming of the violations. The TCEQ found sewage throughout the river, from the wastewater discharge point (i.e. outfall) to 1,000 feet downstream from the outfall. Lab analyses confirmed the TCEQ samples to contain sewage. The sewage had been in the river long enough to cause the growth of attached aquatic plants. As part of TCEQ’s enforcement, Liberty Hill is required to clean up the river sewage.
However, the report does not address the following: When did this sewage discharge occur? Has the sewage discharge been a single event, intermittent event or a steady, continual release? How long has the sewage discharge been occurring? What measures are they taking to prevent future sewage discharges? What are the downstream impacts of the sewage releases?
In addition to the TCEQ-discovered violations, the Liberty Hill plant has had 53 self-reported violations in the past year, according to the report. The plant has a history of violations dating back at least 6 years–violations which include excessive discharge levels of algae-producing Nitrogen and Phosphorous and discharges which include dangerous levels of E Coli bacteria.1 Despite the above infractions, the plant has incurred only minor monetary penalties to date.2
Business As Usual Is A MAJOR Problem
Although the multiple plant violations are disturbing, perhaps a larger problem is that the existing Liberty Hill wastewater permit is far too lax to prevent extensive algae growth in the river. The permit’s maximum allowable Nitrogen level is at least 75 times the level that could cause stream eutrophication. The allowable Phosphorous levels under the permit are 22 times the level that could cause eutrophication. Earlier this year, the Liberty Hill wastewater discharge was increased threefold, from 400,000 gallons per day to 1.2 million gallons per day. This increase was the likely cause for local resident complaints about excessive algae in the river, which led to the TCEQ investigation. Sufficient natural flow in the South San Gabriel river does not exist to offset this massive influx of nutrients. The current wastewater discharge of 1.2 million gallons per day often exceeds the natural river flow, especially during dry summer months.3 The current TCEQ permit allows Liberty Hill to eventually discharge up to 4 million gallons per day of wastewater into the river.4 Such levels likely would cause much greater algae and other water-quality problems in the river.
The diagrams below show the TCEQ water sampling results, indicating high nitrogen and phosphorous levels at and downstream from the outfall. However, the water 0.9 miles upstream of the outfall has low nutrient levels and was reported as clear and algae-free by TCEQ, indicating that the Liberty Hill plant is the source of the algae.
Note on the previous graphs that the Nitrogen and Phosphorous levels decrease downstream, due to absorption by the algae and other vegetation that covers the river downstream from the outfall.
Bacteria levels in the river are also a major concern. Five of the 53 self-reported violations from the past year were for E coli violations. The plant has a history of E coli violations, some self-reported and some discovered by TCEQ, dating back at least 6 years. While the TCEQ samples didn’t show excessive levels of E coli on the day the samples were taken, the fact there is sewage present in the river indicates substantial bacterial contamination of the waterway.
In addition to nutrient and bacterial contamination, there is also possible thermal pollution of the river as a result of the wastewater discharge. This was not addressed in the TCEQ report. Frank Tull, who lives near the San Gabriel River 3.6 miles downstream from the outfall, noted in June 2018 that the river seemed much warmer this year than previous years. When the outfall location was visited the following week, the water temperature of the wastewater was noticeably very warm, much warmer than the river temperature above the outfall. It is likely that the higher wastewater temperature is due to the wastewater sitting in open collection tanks for hours or even days under the hot Texas sun, prior to being discharged into the river. Higher water temperatures encourage more algae growth than lower water temperatures.5
What Can Be Done?
The TCEQ report describes violations by the Liberty Hill plant, corrective action that must be taken, and remediation to remove the untreated sewage from the river. But even if these directives are followed, it won’t solve the problem of the fouling of the river by the Liberty Hill wastewater plant. And as the plant increases their discharge from the current level of 1.2 million gallons per day to 4 million gallons per day in the future, the problems will only get worse.
The TCEQ report doesn’t mention potential impacts of river pollution to local groundwater and related drinking water supplies. Yet the South San Gabriel river recharges the local Trinity Aquifer and contributes to the local Edwards Aquifer, which means river contamination could pollute water supplies. So clearly, something needs to be done.
Because the Liberty Hill plant is operational and has been for years, there is a tendency by local officials to ignore the problem. However, there are several steps that could be taken to clean up the river. For example, the City of Dripping Springs recently reached a settlement with environmental groups and local landowners to apply much of their future wastewater toward Beneficial Reuse (watering of parks and open areas) as well as land-application of their wastewater over empty land parcels.6 The 4000-home Belterra development in the Texas Hill Country has a similar arrangement for their wastewater. Land for such application is available in the area surrounding the Liberty Hill plant. There are also nearby parks, golf courses, and other open areas that could benefit from the reuse of Liberty Hill’s wastewater. However, there is no current interest by local officials to invest the time or money for such an endeavor. Therefore, it is important for local residents and all central Texans to be involved in this issue.
Additionally, the TCEQ needs to reconsider the Liberty Hill permit, which was granted almost 10 years ago, and decrease the allowable limits for Nitrogen and Phosphorous. For comparison, the City of Dripping Springs’ allowable Nitrogen and Phosphorous levels are approximately 1/3 that of the Liberty Hill wastewater permit.
Finally, legislation needs to be enacted in Texas which either abolishes direct discharge wastewater permits or substantially lowers the discharge and water-quality limits for wastewater discharges. Visit www.nodrippingsewage.org to sign our petition and support future legislative efforts to keep our waterways clean and our drinking water supply safe.
For a presentation regarding the threat to Hill Country water from direct wastewater discharges, please visit http://www.hillcountryalliance.org/wp-content/uploads/2014/11/General-threats-to-water-quality_updated_version.pdf