A chlorine leak at the 91st Avenue wastewater treatment plant near Tolleson sent hazmat crews racing to the site early Monday, July 20, 2026, after plant operators reported an active release before 9 a.m. Hazmat teams and other emergency responders moved in to secure the area and start mitigation work. As of the initial response, officials had not released details on any injuries or whether local water service had been affected.
According to KTAR, Phoenix Fire classified the call as a hazardous-materials incident and summoned specialist teams to the West Valley facility. KTAR reported that crews worked alongside plant staff to isolate the leak and evaluate how much chlorine was being released.
What the 91st Avenue Plant Is and Who It Serves
The 91st Avenue facility sits on the north bank of the Salt River at 5615 South 91st Avenue in Tolleson. An EPA fact sheet shows the plant is authorized to operate at a design capacity of 230 million gallons per day and treats wastewater for a network of Valley cities. The plant’s treated outflows also feed the Tres Rios wetlands, which provide additional natural filtration for the effluent.
Ownership and Operations
The facility is owned by a multi-city partnership but operated by the City of Phoenix, which oversees planning, maintenance and emergency response coordination at the site. The City says Tres Rios and the 91st Avenue complex are central to regional wastewater operations and reuse projects, making the plant a critical piece of water and environmental management across the Valley.
Past Trouble at the Site
The plant has not been incident free. Local coverage notes that a November 2025 fire at the facility sent one person to a hospital with burns. KTAR reported that the earlier fire prompted scrutiny of equipment and safety procedures at the large, complex wastewater operation.
Chlorine Hazards and Safety Context
Chlorine gas is a corrosive, toxic substance that can damage eyes, skin and lungs at relatively low concentrations, which is why federal guidance calls for tight controls and emergency planning at facilities that store or feed gaseous chlorine. The EPA’s Response Protocol Toolbox notes that utilities often consider hypochlorite systems to reduce vulnerabilities tied to gaseous chlorine storage and piping, especially where a large release could threaten workers or nearby neighborhoods…