The City of Guelph says it has started testing 2,700 fire hydrants and that some residents may see discoloured water coming out of their taps as a result.
Testing starts in the south end of Guelph and will continue to move north.
There will be no disruption of water service, and no chemicals are used while testing the fire hydrants, the city said. However, the city noted that some residents may experience a short period of discoloured water.
READ MORE: Hot Summer Nights lets residents beat the heat with Guelph fire
Drinking small amounts of discoloured water is unlikely to cause any health issues, but the city recommends running a cold-water tap for five to 15 minutes until the water runs clear.
Discoloured water occurs when minerals naturally present in Guelph’s groundwater combine with chlorine to form small rust particles, which settle on the bottom of water mains and pipes.
Testing fire hydrants involves high-pressured blasts that can disrupt the settled particles.