The field guide
Where protection lives
Every one of these connects something hazardous to drinking water. That is the whole trade: knowing the hazard, the assembly that answers it, and the test that proves the assembly still works.
Lawn irrigation systems
Sprinkler heads sit in soil that carries fertilizer, pet waste and pesticides.
Fire sprinkler systems
Water in fire lines can stand for years, and systems may connect to tanks, pumps or chemical additives.
Boilers and hydronic heating
Boiler water is heated, pressurized and frequently treated with corrosion chemicals.
Restaurants and commercial kitchens
Carbonators, dish machines, ice machines and chemical dispensers all connect equipment full of gas, chemicals or waste heat to drinking water lines..
Apartment and multifamily buildings
Large plumbing networks with boilers, irrigation, pools and mechanical rooms create multiple cross-connections behind one meter..
Medical and dental facilities
Lab sinks, sterilizers, dental vacuum systems and treatment equipment make health-hazard cross-connections routine in clinical space..
Car washes
Recirculated wash water, detergents and wax systems sit directly on pressurized water connections..
Pools, spas and fountains
Fill lines that drop below the water line, chemical feeders and autofill valves connect treated recreational water to the supply..
Garden hoses and hose bibbs
A hose left submerged in a bucket, pool or chemical sprayer is the most common cross-connection in any home.
Homes with wells or auxiliary water
A property with both a well and a utility connection can push non-potable well water into the public system if the two are ever cross-tied..
Food and beverage processing
Process water, cleaning-in-place chemical systems, and heated vats sit on plant water infrastructure at industrial scale..
Commercial buildings generally
Every mechanical room, roof tank, cooling tower and tenant improvement adds potential cross-connections behind the meter over a building's life..