Minn. R. 4626.1085
BACKFLOW PREVENTION DEVICE; WHEN REQUIRED. 5-203.14
A. A plumbing system must be installed to preclude backflow of a solid, liquid, or gas contaminant into the water supply system at each point of use at the food establishment according to chapter 4714. P1 B. A backflow prevention device must be located so that it may be serviced and maintained.