Backflow testing
A backflow prevention assembly is tested to show it still stops water from reversing into the public supply. The launch cities publish who may submit those tests.
What the city lists are
Houston, Irving, Miami-Dade, Tampa, and Pensacola each publish a roster of backflow testers. This site copies those rosters. It does not add companies that were not on the file we fetched.
Open a city page for the copied list, the source link, the list date, and that city's deadline notes.
What a passing test does not settle
A name on a city list means the city accepted that company or tester onto the roster it published. It does not mean this site checked insurance, workmanship, or price. Confirm the license and the current city file before you hire.