TCEQ reverses on Liberty Hill water violation
By Mike Eddleman
The Texas Commission on Environmental Quality (TCEQ) confirmed Tuesday morning that the alleged radium contamination in the Liberty Hill water supply was reported in error due to incorrect calculations.
“Based on TCEQ’s review of all of the city’s sampling data for radium, it was discovered that the calculation to determine compliance with combined radium did not include all of the city’s previous sample results,” said Brian McGovern with TCEQ.
He said that when all sample results were included that the City’s compliance value was 4 pico curies per liter, below the maximum contaminant level of 5 pico curies per liter as allowed by the U.S. Environmental Protection Agency.
“We are monitoring this just to make sure that nothing happens, and we take active measures just as quickly as we find something,” said Liberty Hill Mayor Rick Hall. “We’re doing what’s best for our community and we’re making sure everybody is safe. I have no concerns from drinking any of our water coming from any of our wells or our surface water out of Lake Travis.”
The radium maximum contaminant level is calculated on a quarterly basis using a running annual average due to the long-term health effects of the contaminant. Compliance is not based on a single sample result and the running annual average is calculated utilizing the most recent four quarters of data at an entry point to the distribution system.
The TCEQ said it uses a third party contractor to collect samples which are then submitted to three laboratories that are accredited by TCEQ and adhere to EPA drinking water laboratory certification requirements.
The sample from the well in question was taken in January and TCEQ notified the City of Liberty Hill of the alleged violation by letter on June 27.
The required notification to customers came by letter last week, sent by the City of Liberty Hill per TCEQ requirement to notify water customers within 30 days of the alleged radium contaminant level violation. The letter raised many questions and concerns throughout the community.
The letter stated the combined radium level in the first quarter of 2019 was 6.4 pico curies per liter but did not address the annual average.
The testing is for combined radium 226 and 228, which, according to data from the Water Quality Association in Illinois are naturally occurring through the radioactive decay of uranium and thorium in rocks and soils.
McGovern said that 79 public water systems in Texas exceeded the maximum radium contaminant level based on the running annual average between 2016 and 2018.
According to Hall, the well with the high quarterly reading did not have a history of high levels of radium. The well – Well Site No. 2 on Loop 332 – was taken offline and will not be reactivated by the City. Hall said the City was in the process of officially shutting it down through the TCEQ notification process, but that it has already ceased pumping water and would be capped.
The well in question provided less than 10 percent of the total water consumed in the City, and was mixed with the other sources of water – from wells and pumped from Leander – further diluting the higher radium level in the single quarter reading.
“It all goes into our towers, the one downtown and the one on 29, and it mixes with everything and the volume of water we were getting out of Well No. 2 was probably around six or seven percent of the total volume,” Hall said. “Nobody is getting water directly from that well without it being mixed. It goes through the chlorination process and through the mix process before anything gets into anybody’s home.”
The City will be sending out letters detailing the situation and Hall said the city would be making the historic sample readings from all sources available to the public.