Definitions of Terms for Backflow and Cross Connection

Cross Connection Control
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FAQs Certified Testers
Backflow
The reversal of normal flow of water (potable or non-potable) or other substances into a drinking water system (DWS) that may be caused by back siphonage or back pressure in the presence of a cross connection.
Back Siphonage
Backflow caused by pressure that is below atmospheric in the supply system.
Back Pressure
A pressure higher than the supply pressure.
Cross Connection
Any actual or potential connection between the waterworks and any source of pollution, contamination or other material or substance that could change the quality of water in a drinking water supply (DWS).
Premise Isolation
Consists of having a backflow preventer installed where the water service enters the building or facility. It is the minimum requirement for all industrial, commercial, and institutional (ICI) customers under the Cross Connection Control Program (CCCP).
Zone Isolation
When an area is protected with a backflow preventer that separates it from another potential contamination area. This type of isolation only protects a section of piping within the system.
Fixture Isolation
When a backflow preventer is installed at the source of the potential contamination, like a boiler supply feed, for example. This type of isolation only protects a section of piping within the system.
Backflow Prevention Device
One-way valves installed in plumbing systems to prevent backflow of potentially contaminated water or substance(s) into potable DWS
Survey Reports
Consists of a detailed inspection of the facilities’ internal plumbing systems to identify cross connections or potential cross connections that could pose a threat to the potable water supply. The reports must be completed by Certified Backflow Prevention Device Testers and must include the hazard level as well as recommendations for resolving the internal cross connections. Reports must also identify the device required for premise isolation. The report must be signed by the tester and the owner of the facility.
Test Reports
A test report consists of a detail test performed annually by a Certified Backflow Prevention Device Tester that identifies whether the backflow prevention device is functioning properly. Test reports must be forwarded to the CCCP office for acknowledgement and input into the software program in order to satisfy the yearly requirement under the CCCP and By-law 2006-122 (Water Use).