The Tempe Public Works Department has said the city’s drinking water has now returned to compliance after it exceeded the maximum containment levels of trihalomethanes (TTHMs), a known carcinogen, in June.
A recent compliance sampling testing for TTHMs was conducted and showed the city is back to the Environmental Protection Agency's Safe Water Standard.
In May, during a routine quarterly sampling to check for TTHM compliance, one of eight locations inside the city’s western boundary exceeded the maximum TTHM levels. According to the Public Works Department, the sample was from site A-10, which is at the corner of Baseline Road and 48th Street.
Within 48 hours after of the sampling showing excessive TTHMs, the Public Works Department said it took measures such as system flushing, blending groundwater with surface water and using wells, and made chemical adjustments at its water treatment plants.
According to the department, these measures reduced TTHMs at the site and throughout the system.
“Having returned to compliance, Water Utilities’ strategic team is implementing a plan to ensure that the City meets its goal of 100 percent compliance with Safe Drinking Water requirements in perpetuity, as it had since promulgation of the Safe Drinking Water Act until May’s sampling event,” the department said in a statement.