Backflow are on every commercial property as a city requirement. Backflow Prevention devices are required on commercial properties to prevent the backflow of water back into the city system. Without these devices our city water system would be contaminated with pesticides, landscaping chemicals, and even carbonation. Backflows are installed on irrigation lines, domestic water lines and even soda machines in restaurants.
Each person that tests backflows has to undergo intense training to become a certified backflow assembly tester, this certification is only good for three years, then the tester has to retest to confirm they have adequate knowledge to test and certify these backflow preventers.