Where protection lives
Homes with wells or auxiliary water
A property with both a well and a utility connection can push non-potable well water into the public system if the two are ever cross-tied.
The protection you will typically see
Authorities treat auxiliary water sources as high hazard and commonly require containment protection at the service.
Who decides
The water authority assigns the required protection by degree of hazard and enforces the test schedule. Requirements vary by jurisdiction; the authority's cross-connection control program is the answer to every "do I have to" question on this page.
What the owner should know
If you have both a well and city water, tell your water authority before they find it. The protection requirement exists whether or not the systems are supposed to be connected.
Common questions
Why do homes with wells or auxiliary water need backflow protection?
A property with both a well and a utility connection can push non-potable well water into the public system if the two are ever cross-tied.
What kind of backflow preventer is used?
Authorities treat auxiliary water sources as high hazard and commonly require containment protection at the service. The assembly type is assigned by your water authority based on the degree of hazard, not chosen by the property owner.
How often does it get tested?
Testing is typically annual where required, on a schedule set and enforced by the water authority. A certified tester performs the test, tags the assembly, and files the report.
Other places protection lives
| Lawn irrigation systems |
| Fire sprinkler systems |
| Boilers and hydronic heating |
| Restaurants and commercial kitchens |
| Apartment and multifamily buildings |
| Medical and dental facilities |
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