Residents in parts of Windsor, Ontario, may see bright green water in their area due to utility testing [1, 2].

The phenomenon is the result of a controlled release of dye by Enwin, the local utility company, to verify the functionality of water-treatment equipment [1, 2]. Because the sight of neon-colored water often triggers public alarm or reports of contamination, the utility issued a public notice to prevent unnecessary panic.

Enwin announced the testing schedule on July 9, 2026 [1]. The company said that the bright green runoff is expected to be visible in certain parts of the city over the next few days [2].

Officials said that the substance causing the discoloration is a biodegradable dye [1, 2]. This specific type of dye is commonly used by utility providers to trace the flow of water through complex systems and identify leaks or blockages without introducing harmful chemicals into the environment [1, 2].

The company said that the appearance of the water is temporary and does not indicate a failure in the water treatment process or a threat to public safety [1, 2]. Residents are advised that the discoloration is a normal part of the scheduled maintenance, and testing procedures currently underway in Windsor [2].

Enwin has not released specific details regarding which neighborhoods will be most affected, but the dye is expected to move through drainage channels and runoff areas as part of the system check [1, 2].

“Residents in parts of Windsor, Ontario, may see bright green water in their area.”

The use of biodegradable tracers is a standard industry practice for auditing municipal infrastructure. By visualizing the path of water, Enwin can ensure that treatment equipment is operating efficiently before the onset of seasonal demand shifts, reducing the risk of long-term system failures.