CALEXICO — The Calexico Water Treatment Plant’s water system recently exceeded drinking water standards for total trihalomethanes, also known as TTHMs, according to a Jan. 23 press release from the city.
“While we are required to notify residents and
customers of any exceedance of standards, the water treatment plant wants to
confirm with the public that there is no immediate risk,” the city stated in
TTHMs are common disinfection process byproducts that
form when chlorine reacts with natural organic material present in the source
water. Although an increase of TTHMs was detected, the water remains safe to
drink and use for cooking, bathing and cleaning, according to the press
This is not an emergency and city water customers do
not need to boil water or take other actions. The U.S. Environmental Protection
Agency and State Water Resources Control Board Division of Drinking Water have established
public notification rules and tiers under which specific violations are
assigned. The TTHM violation is a Tier 2 violation of the drinking water
regulations. Tier 2 violations are considered less urgent than Tier 1
violations because there is little immediate risk to consumers. Tier 2
violations require a public notification delivered to customers after a
violation is discovered.
The Calexico Water Treatment Plant is currently evaluating the feasibility of implementing several treatment options in order to meet TTHM standard. The city is working closely with the State Water Resources Control Board, Division of Drinking Water to resolve the issue. We anticipate resolving the issue within 12 months.