The prevention of non-potable water or any deleterious substance from entering the distribution system is extremely important to public safety. The PUD recognizes the Washington State Department of Health regulations (WAC Chapter 246-290-490) regarding the protection of the public via minimum requirements for design, construction, operation, and maintenance of public water supplies. All developers or applicants constructing public water mains or facilities should be familiar with, and comply with, these requirements. These referenced regulations and standards are a minimum, and the PUD specifically reserves the right to require additional safety features and items as may be deemed appropriate by the PUD. Premise isolation by a reduced pressure backflow assembly (RPBA) approved by the PUD is required for all customers with access to auxiliary water supplies connected to a piping system, whether or not an interconnection exists between the auxiliary supply and the PUD water system.