Water quality announcement for Willow Valley/King Street customers

At EPCOR we’re committed to providing water and water service you can count on. As part of that commitment, our water quality experts conduct more than 300,000 tests each year to monitor contaminants.

This notice, in accordance with Arizona Department of Environmental Quality requirements, is to let you know of recent tests specific to EPCOR customers located in the area highlighted on the map in the attached PDF.

In April 2025, routine monthly compliance tests were conducted that indicated chlorite levels in the Willow Valley/King Street distribution system were slightly above the maximum allowable level allowed by federal drinking water standards. The standard, or maximum contaminant level, for chlorite is 1.0 mg/L and the average level of chlorite during the month of April was 1.09 mg/L.

We understand that this information may cause concern. Please know that we took immediate action to address the issue. We worked closely with regulatory agencies, conducted additional monitoring, and made operational adjustments to bring chlorite levels back into compliance as quickly as possible. Additional chlorite samples collected on April 24, 2025, showed the average chlorite level in the distribution system at 0.62 mg/L, thus meeting the water quality standard. 

Read the full notice and view the map.

Releated information:

• 2024 interim Willow Valley King Street water quality report