Drinking water standards must meet a Maximum Contaminant Level (MCL) established by the EPA and GA EPD. The MCLs limit risks to people from chemicals in drinking water. Some MCLs address the daily amount consumed (for chemicals that pose an immediate risk), and others address the amount averaged over a long period of time (for chemicals that pose a long‐term risk).
The MCL for TTHM is 0.080 mg/L, or 80 parts per million (ppm). We determine the MCL by calculating the average of four quarterly samples collected at our eight testing locations. If a sampling site is over 0.080 mg/L, a water system receives a permit violation.
The PUD exceeded the MCL of 0.080 mg/L for TTHM with a rolling average of 0.082 mg/L at one of our eight sampling sites found on the southeast end of Barnett Shoals Road.