Cross Connection Program Common Questions
Below are some common questions we receive about cross connections.
What is a cross connection?
A cross-connection is any temporary or permanent connection between a public water system or consumer's potable water system (drinking water) and a source or system containing non-potable water or other substances.
Common residential examples of cross connection hazards (source of contamination) that need to be protected with a backflow preventer:
- Fire sprinkler system
- Lawn irrigation systems
- Auxiliary water supply (wells)
- Hot tubs / Spas
- Swimming Pools
- Hose bibs / Garden hose
What is backflow?
Backflow is the undesirable flow reversal of water, liquids, gases or other substances into the City of Raleigh Public Water Supply.
Backflow can occur when water pressure in the distribution system drops relative to a service line. This can happen due to the use of hydrants for fire fighting, water main break, high usage, or backpressure from a pump.
What is a backflow assembly?
A backflow is an assembly that allows water to travel in only one direction. When working properly it stops a contaminant such as pesticides, fertilizers or animal waste from entering the potable water supply when either a backsiphonage or backpressure event occurs. A reduced pressure assembly (RPZ) is required for both residential lawn irrigation systems and when a resident uses public domestic service while also having a private irrigation well within the property limits.
Who is required to have a backflow assembly?
Every connection to the potable water service supplied by the public water system or residents who have installed a private irrigation well are required to install a backflow assembly on their public water service. Protecting the potable water supply using backflow assemblies is in accordance with the Safe Drinking Water Act Amendments of 1996, North Carolina Public Water Supply and the Raleigh City Code. There is no grandfather clause exclusion for any connection to the public water supply.
Why does the backflow assembly need to be tested?
A backflow assembly is a mechanical assembly that is subject to failure. It is impossible to tell if it is working by appearance only. An operational test using a differential gauge is required to determine if the backflow is working properly.
How often is a backflow assembly required to be tested?
A residential irrigation backflow assembly (RPZ) is required to be tested every 3 years. All other backflow assemblies are to be tested annually. Where an RPZ is installed because a private well exists and the residence is served with public potable water, the RPZ for the potable water must be tested annually. (Raleigh City Code 8-2148 and 8-2154)
What do i do if my backflow assembly fails a test?
A failed assembly will need to be cleaned, repaired or in some cases it may need to be completely replaced. After cleaning, repair or replacement a successful re-test needs to be performed.
Who pays for this test?
Installation of a backflow assembly is required by the NC Plumbing Code and therefore is installed on private property. Raleigh City Code defines the consumer as the responsible party to maintain and test their assembly. (Raleigh City Code 8-2154)
Does the city provide testing service?
No. The City maintains a list of testers approved to work within the Raleigh water system. A tester is required to maintain a certification from a locally approved certification school, obtain annual calibration for a differential or electronic test kit, and other requirements as required by the Director of Public Utilities. Testers who do not meet these requirements are removed from the list until they have met all requirements.
Who can install a backflow assembly?
According to NC licensing laws, a plumber or general contractor licensed to install water service within 5' of the building (when the backflow is installed exterior to the building) may install a backflow on the potable water service including irrigation. A Fire Sprinkler contractor may install assemblies for fire sprinkler systems and private fire hydrants only.
Do I have to obtain an operational test for a newly installed backflow assembly?
Yes. Backflow assemblies may be subjected to environmental conditions that could cause wear or deterioration to the seals and parts of the assembly prior to installation.