Our water is safe to drink and use. Federal and state regulations in place are scientifically proven to keep drinking water safe and NTMWD meets those requirements.
The disinfection process eliminates bacteria and viruses in the water supply and distribution system. NTMWD uses common disinfectants: chlorine, chloramine (chlorine + ammonia) and ozone. Forty-five percent of the U.S. population is served by public water supplies using chloramine.
Each year, NTMWD conducts a temporary 30-day maintenance process accepted by the Texas Commission on Environmental Quality (TCEQ) and the Environmental Protection Agency (EPA). The maintenance period ended Monday, March 26.
Chlorine levels during this period were consistent with normal year-round operations and within the annual average required by TCEQ. The only change during this annual maintenance period is the discontinuation of ammonia while continuing all other treatment processes and testing. The odor is more noticeable due to the lack of ammonia.
NTMWD collects and processes hundreds of samples each day and reports results in our online water quality reports and to regulatory agencies. The results of these analyses, including tests continued routine tests conducted during the maintenance period, and past experience have shown that, the levels of disinfection by-products remain well within regulatory standards. However, in response to the increased interest during this year’s annual chlorine maintenance, additional samples were collected from the NTMWD distribution system on March 16 and tested by an independent lab for disinfection by-products (trihalomethanes or THM). Samples collected in Plano (northern system) and Forney (southern system) showed THM levels at 54 and 71 parts per billion (ppb) or (i.e. 0.054 and 0.071 mg/L), respectively. These levels are well below the limit set by the Environmental Protection Agency (EPA), which requires that public water systems maintain an annual average of THMs below 80 ppb. NTMWD has posted the independent lab report online.