The firms listed here have been certified to test backflow preventers.

Select your region in the drop-down list to filter listings for your local area -
or search for a particular firm or city using the Search box.

Test Form

 Find your certified tester by region.

The listing of backflow prevention assembly testing firms is provided as a convenience and is not intended as an endorsement or referral. This is not a complete or comprehensive listing. HydroCorp suggests contacting several backflow prevention assembly testing/plumbing companies before deciding which to use. HydroCorp cannot recommend one testing company over another. You may elect to use a tester not on this list; however that tester/plumber must be certified to test in the appropriate city/state/jurisdiction. HydroCorp assumes no liability for the service or quality of work performed by a listed company/tester/plumber on this page. The companies displayed on this list have no affiliation with HydroCorp or HydroCorp employees.

If you are a plumber/testing company and the information listed above is incorrect, please email for any changes or call 248-250-5026. Listing information is updated monthly.

Additional Resource Links: