The following businesses must use backflow prevention devices, unless exempted:

• Auto repair shops
• Breweries
• Canneries
• Commercial car washes
• Dye plants
• Exterminators
• Food processing plants and meat packers
• Funeral parlors
• Greenhouses
• Hospitals, clinics and laboratories (including veterinary hospitals)
• Large residential dwellings with water boilers that use rust-inhibitors or other treatment chemicals ("treated water boilers")
• Laundries and dry cleaners
• Medical and dental offices
• Metal platers
• Photo-processing facilities
• Paper processors
• Premises with multiple water service lines
• Premises with roof tanks and elevated storage lines
• Sewage treatment plants or handling facilities
• Shipyards and marinas
• Tanneries

To install a backflow you must hire either a:

• Professional Engineer (PE), or
• Registered Architect (RA)

The PE or RA must follow the procedures in the DEP's Cross-Connection Brochure. The brochure, required documents, and forms are available online.

Learn more about cross connection control and water backflow prevention.

Exemptions must be filed on behalf of the property owner by either a:

• Professional Engineer (PE), or
• Registered Architect (RA), or
• Licensed Master Plumber (LMP)

To file:

1. All required info must be in a typed letter on letterhead
2. The letter must state that all necessary exemption conditions have been met
3. It must be sent to the DEP for approval

An exemption guide is available online.

Learn more about cross connection control and water backflow prevention.