Backflow Device Workers determine the devices that separate potable and non-potable water function properly, which is required by code. I take my job seriously, I am responsible to insure a customers drinking water is safe from backflow. I have seen many scenarios over the last 14 years that would give pause to drinking tap water. Irrigation backflows are considered high hazard by plumbing code. Some customers don't understand why they are required to have testing done, until explained to them that they are protecting their neighbors as well as themselves against the massive amount of chemicals people use to make their grass green.
I believe it is necessary for Backflow Testers to be licensed, I can't imagine why DPOR would consider dropping the certification process for this profession.