What is a cross-connection?
A cross-connection is an unprotected actual or potential, direct or indirect connection between a potable water system and any source or system containing unapproved water or a substance that is not or cannot be approved as safe and potable.
Why do such cross-connections exist?
Plumbing systems are installed by persons unaware of inherent dangers of cross-connections and protected with inadequate devices. To combat the dangers of cross-connections, approved backflow prevention assemblies must be in place and tested annually or more frequently to ensure proper operation and protection from cross-connections.
What is a backflow-prevention assembly?
Manual of Cross-Connection Control, 7th Edition-1985 - It was determined that the term ASSEMBLY would be used throughout the manual in place of DEVICE to reinforce the backflow preventerâ€™s inclusion of shutoff valves and test cocks as integral components.
Backflow prevention assemblies protect the potable water system from minor, moderate, and severe hazards. There are thousands of cases of backflow contamination reported each year. Some cases can be fatal. Backflow prevention assemblies are required by law where needed and must be installed in accordance with plumbing or building codes.
A backflow prevention assembly has test cocks and shut-off valves and must be tested by a certified backflow tester each year, if relocated or repaired, and when installed. It is important that the backflow prevention assembly match the particular hydraulic conditions at that location and is suitable to protect against the degree of hazard present.