For the last year the level of arsenic in the City of Williams’ drinking water was nearly double the U.S. Environmental Protection Agency’s safety standards.
Officials say they’re working to fix the problem.
“The city has switched water sources to treat surface water and the wells are not in service,” says Williams Public Works Director Aaron Anderson. “We are working on treatment options for the effected wells. The wells will not be used until a suitable removal filter/vessel has been installed and tested.”
In a letter sent to residents on Dec. 10, 2025, Williams officials revealed arsenic levels averaged 17 parts per billion throughout 2025. The EPA’s standard safe amount is 10 parts per billion.
The city has stopped using the affected wells and is now drawing water from surface intakes at Dogtown Lake that the Arizona Department of Environmental Quality says meets all federal standards.
“At this time, residents can rest assured that they are receiving water that meets all federal drinking water standards including arsenic … On Jan 23, 2026, the city discontinued production from the last remaining groundwater well. The groundwater wells will remain inactive pending ADEQ approval and installation of appropriate treatment prior to reactivation,” says Alma Suarez, a spokesperson for the Arizona Department of Environmental Quality.
Williams’ water system serves more than 3,100 full-time residents. Officials say the spike in levels doesn’t pose an immediate risk to the community.
Arsenic is naturally occurring in the Southwest’s groundwater because of regional geology. According to ADEQ, drinking water standards for arsenic are meant to protect public health over a lifetime of exposure and it’s classified as a “chronic contaminant.”
But those who are exposed to arsenic over many years or are immunocompromised could face health problems like skin lesions and even cancer.
