ASSE 6040 key terms

Any actual or potential link between a potable water supply and a source of contamination or pollution, allowing used or unsafe water to flow back into the drinking water system.

The unwanted reversal of normal water flow direction in a piping system, carrying nonpotable water or other substances toward the potable supply.

Backflow caused by negative or sub-atmospheric pressure in the supply piping, which draws nonpotable liquid into the potable system through a cross-connection.

Backflow caused when downstream pressure exceeds the pressure of the potable supply, pushing nonpotable water backward into the drinking water piping.

The presence in water of any substance that degrades its quality or appearance but does not necessarily create an immediate health hazard to consumers.

The introduction of any substance into potable water that creates an actual hazard to public health, such as sewage, toxic chemicals, or disease-causing organisms.

A cross-connection condition capable of introducing contaminants that cause illness, injury, or death, requiring the highest level of protection.

A cross-connection condition that could degrade water quality or aesthetics but is unlikely to cause sickness or injury, such as a low-toxicity pollutant.

The systematic process of rating the degree of risk a cross-connection poses, typically as health or non-health hazard, to determine the protection required.

A physical separation between a potable water outlet and the flood level rim of a receiving vessel, providing the highest degree of backflow protection.

The lowest edge of the opening of a fixture or receptacle through which water would overflow, used as the reference point for measuring an air gap.

A testable assembly with two spring-loaded check valves and a hydraulically operated relief valve, providing protection against both backpressure and backsiphonage health hazards.

A testable assembly of two independently acting check valves used to protect against non-health hazards from both backpressure and backsiphonage.

A testable device with a loaded check valve and an independent air inlet valve that opens at low pressure, protecting against backsiphonage only.

A non-testable device with a check valve and an air inlet that opens at atmospheric pressure, used where backpressure cannot occur.

A testable assembly combining a check valve and an air inlet that opens only during backsiphonage, allowing installation where a standard vacuum breaker would spill water.

A valve that allows water to flow in one direction only, closing automatically to prevent reverse flow within an assembly or device.

The hydraulically operated component of a reduced pressure principle assembly that discharges water to drain when a fault allows the pressure differential to reverse.

A device that admits air into piping when internal pressure drops below atmospheric, breaking the siphon that would otherwise cause backsiphonage.

Protecting a water utility's distribution system from hazards on a customer's property by installing a containment assembly at the service connection.

Backflow prevention installed at individual fixtures, appliances, or processes within a building, addressing specific hazards that premises isolation alone cannot cover.

The backflow prevention assembly installed at the meter or service connection to isolate the entire premises from the public water system.

A structured survey of a facility's plumbing and processes to identify cross-connections, rate their risk, and determine appropriate protection methods.

An on-site inspection of a premises that documents water uses, cross-connections, and existing protection to support program decisions and compliance tracking.

The point where a customer's private plumbing connects to the public water distribution main, typically the location for containment protection and metering.

A documented on-site procedure that measures the performance of a backflow assembly's check valves and relief valve against established pass/fail criteria.

The measured pressure difference across a check valve or relief valve, used in field testing to confirm the assembly opens and closes within acceptable limits.

A person who has completed recognized training and testing and holds current credentials authorizing them to test backflow prevention assemblies.

A standardized record of assembly test results, including pressures, pass or fail status, tester identity, and date, submitted to the water authority.

The organized maintenance of cross-connection program data such as surveys, test reports, permits, and repair histories for retrieval and audit.

Periodic review of a cross-connection control program's coverage, compliance rates, and outcomes to identify gaps and guide improvements.

The regulatory obligation for owners of testable backflow assemblies to have them tested at least yearly by a certified tester and submit results.

Pressure buildup in a closed plumbing system as heated water expands, which can damage components and must be addressed when backflow protection closes the system.

The agency or official responsible for enforcing cross-connection control rules, approving assemblies, and requiring corrections within its area.

A legally binding rule adopted by a government body that sets cross-connection control requirements, enforcement powers, and penalties within its scope.

A consensus technical document that specifies assembly design, performance, and testing criteria, often referenced by codes and regulations.

The use of a device such as an air gap or vacuum breaker at an individual fixture or appliance to prevent backflow at that point of use.

The severity of risk a cross-connection presents, ranging from low to high, used to match the type of backflow protection to the situation.