A Texas State water-well that provides potable water to campus tested positive for E. coli bacteria on the pre-treatment side of the system May 24. No contamination was found after disinfection on the post-treatment side of the system.
The well, located off Student Center Drive, tested negative for bacteria May 29. Sheri Lara, director of utilities operations, said the pre-treatment side of the system denotes the raw water coming in from an aquifer. The post-treatment side of the system signifies the water after chlorination and filtration, which is then considered potable water, or suitable for human consumption.
Lara said the E. coli bacteria present on the pre-treatment side of the system could have been the result of different runoffs of rainwater percolating back into the aquifer.
She said when the city experiences rain events water sometimes travels into different areas of the aquifer, which then flows into the wells. Rainwater travels along the ground where animals have tread, which eventually soaks into the aquifers. This could have cause the presence of E. coli bacteria, Lara said.
“E. coli is everywhere,” Lara said. “It comes from animals, humans and waste products, those types of things.”
Lara said when E. coli is found in one well, it is usually found in several surrounding wells.
Jon Clack, assistant director of Public Services for the City of San Marcos, said they took a water sample around the end of May that tested negative for E. coli bacteria. He said the bacteria has been present in the city’s water in the past, but recently there have been no tests that have been positive for E. coli.
Lara said the last time E. coli was found in a San Marcos water-well was about two years ago.
Texas State conducts daily and weekly tests of its water. The university reports the tests and treatment of the water to the Texas Commission on Environmental Quality and follows the American Water Works rules and standards for the treatment of water.
Lara said Texas State won the Total Coliform Rule program award for 2008–2009 and 2009-2010 as part of the Public Drinking Water Recognition Program by the Texas Commission on Environmental Quality.
To receive this recognition, the water system must meet certain criteria, such as that the water system must be public and active for 24 consecutive months, and has had no Total Coliform Rule violations during that 24-month period.
According to the commission’s website, the Total Coliform Rule requires all public water systems to monitor water in the distribution system for the presence of total coliform. Coliform, or coliform bacillus, includes bacteria such as Escherichia coli, better known as E. coli.
The Total Coliform Rule was set forth by the Environmental Protection Agency in 1990, setting health goals and legal limits for the presence of total coliform in drinking water. Every public water system is required to test for the presence of coliform bacteria in order to protect the public from waterborne illness, according to the website.
“(E. coli) is something we test for because we know that humans are sensitive to it,” Lara said.
Lara said the university has one water-well and two pumps on campus that provide potable water to the university. They provide water to restrooms and water fountains on campus.