When disasters disable drinking water systems, communities require more than bottled water to function. They need reliable volumes of safe water for cooking, cleaning, and medical care over days or weeks, and delivering that capacity quickly is a persistent challenge. The Water-on-Wheels Mobile Emergency Water Treatment System, known as the WOW Cart, is designed to close that gap.
The cart was developed through a partnership between the U.S. Environmental Protection Agency and the nonprofit WaterStep, formalized under a Cooperative Research and Development Agreement. Under this arrangement, WaterStep handled design, engineering, and fabrication, while the agency contributed technical assistance, environmental sampling, and disinfection research, including practices for granular activated carbon and UV treatment.
Built for rapid deployment, the unit weighs under 500 pounds, fits in the back of a pickup truck, and can be carried by two people. Local volunteers can be trained on-site to operate it, avoiding delays while waiting for specialists. The treatment train layers pre-filtration with granular activated carbon or ion exchange media, on-site chlorine gas generation from ordinary table salt, and UV-C disinfection. It can run on generators, batteries, or solar panels, producing up to 10,000 gallons per day to a folding 1,250-gallon bladder tank.
Since 2020, WOW Carts have been deployed nationally and internationally, including after Hurricane Laura in Louisiana and across a series of tornado and flood emergencies in Kentucky. These field uses underscore the system’s role in maintaining access to safe water while permanent infrastructure is repaired.
On September 18, EPA Region 7 showcased the technology in Lawrence, Kansas, during National Preparedness Month at an event held with the Kansas Rural Water Association, WaterStep, and FEMA. The event emphasized preparedness and highlighted the cart as a resiliency tool that can be trained up quickly for local operators and pre-positioned to support essential needs after future incidents.
