Backflow prevention ensures that the supply of drinking water, in your facility and the City water mains, is protected against the entry of any contaminants, pollutants, infectious agents, or other materials or substances. In most cases, this is achieved by the installation of an appropriate backflow prevention device at the water connection where this potential exists. In some circumstances, the main water supply must also be isolated with the installation of a backflow prevention device at or near the water meter.
A building permit for plumbing will be required for the installation of any new testable backflow prevention device. Replacement of existing testable devices would require a permit if the type, size, or location of the device is being changed. Removal of a testable Source Isolation backflow preventer also requires a permit.
In accordance with the Ontario Building Code and City of London Water By-law #W-8, any existing or new reduced pressure backflow preventers, double check valves and pressure vacuum breakers are required to be inspected and tested upon installation, when cleaned, repaired or overhauled, when relocated - and annually thereafter - by a tester registered with the City of London. No person shall without the permission of the City remove any cross connection control or backflow prevention devices.
A list of certified Cross Connection and Backflow Prevention Device Testers who have registered with the City of London as of the date noted at the top of the list is available. Please contact these Registered Testers (see pdf in right-hand menu) directly as they are not employed by the City of London. While every effort is made to ensure that the most up-to-date list appears on this page, changes can occur frequently. Current lists are available from the Development & Compliance Division at 519 661-4555.
Testing and Inspection reports for the Backflow Prevention & Monitoring Program, along with instructions for submitting them, are now available on-line for use by registered testers only.