Irrigation backflow preventers allow water to travel in only one direction out towards your landscaping and never in towards your drinking water Most cities and municipalities require the backflow to be tested by a certified contractor on a regular basis Typically you will receive a letter in the mail regarding the requirement and when its due Doctor sprinkler is an approved contractor for all local cities and municipalities We will test your backflow and send the results to the city In the event your backflow needs to be repaired or replaced we can do that as well