Many buildings have been vacant for months due to pandemic shutdowns. As Ontario enters its second stage of reopening the province, owners and managers are responsible for water flushing activities to restore water quality and ensure the safety of drinking water. Sometimes this process could take up to 12 weeks for returning a building back to service.

The Ministry of the Environment, Conservation and Parks has released a new resource to help with this process. The Guide for Maintaining Building Plumbing After an Extended Vacancy outlines procedures to ensure water in a building is safe. It is also important to communicate with tenants, local public health units, and, if necessary, the municipality, to ensure water quality is delivered.

When the water use declines in a building for an extended period of time, the quality of the water standing in the plumbing pipes will deteriorate due to a decrease in disinfection residual, increased corrosion of metals and an increase in the temperature of the standing water remaining in the pipes. If water sits in pipes for too long this can create favourable conditions for the regrowth of pathogens such as Legionella and Mycobacterium avium—both harmful to human health.

More information or any questions can be directed to Rob.Dumancic@ontario.ca.