ASSE 6040 cheat sheet

Cross-connection: any actual or potential connection between a potable water system and any source of contamination or pollution.

Backflow is reverse flow of water, caused by either backsiphonage (supply-side pressure drop) or backpressure (downstream pressure exceeding supply pressure).

Backsiphonage occurs when supply pressure drops below atmospheric, creating a partial vacuum that draws nonpotable liquid into the piping.

Backpressure occurs when a downstream pressure, such as from a pump or elevated tank, exceeds the pressure of the potable supply.

Contamination is a substance that creates an actual hazard to public health; pollution degrades quality but does not create a health hazard.

An air gap is the vertical unobstructed distance between the lowest opening of a supply pipe and the flood-level rim of a receiving vessel.

The cross-connection control hierarchy: air gap, reduced pressure principle assembly, double check valve assembly, then vacuum breakers and check valves.

A cross-connection control program is the administrative and physical system used by a water supplier to protect the public water system from contamination.

A single cross-connection event can contaminate an entire distribution main serving thousands of people.

Backflow incidents cause gastrointestinal illness, chemical poisoning, and in some cases death from pathogens or toxic substances.

Common high-risk hazards include sewage, chemicals, pesticides, hospital waste, and industrial process water.

The 1933 Chicago World's Fair amoebiasis outbreak, linked to a cross-connection, sickened thousands and is a historic public health case.

Health risk is assessed by toxicity, pathogen content, and the likelihood and duration of exposure.

Pollution degrades water quality and aesthetics, whereas contamination can cause illness or injury.

Public notification and boil-water advisories are required when a contamination event is confirmed or suspected.

The safe drinking water framework treats cross-connection control as a critical barrier against intentional and accidental contamination.

An air gap is the only absolute protection against backflow; it requires no testing but must be physically maintained.

A reduced pressure principle assembly (RP) uses two spring-loaded check valves and a differential-pressure relief valve; the relief valve discharges when the differential drops below about 5 psi.

A double check valve assembly (DC) has two check valves and is used for non-health hazards only.

A pressure vacuum breaker (PVB) has a loaded check valve and an air inlet; it cannot be used where backpressure exists.

An atmospheric vacuum breaker (AVB) must be installed downstream of the last control valve and cannot be subject to continuous pressure.

A spill-resistant vacuum breaker (SVB) can withstand continuous pressure and is used on systems such as boiler feed lines.

A hose-bibb vacuum breaker is a small device for hose connections; it must remain installed and be checked periodically.

A dual check with intermediate vent (DuCV) is a device for low-hazard protection at the service connection.

An RP assembly must be installed with adequate drainage and a minimum clearance above flood level for the relief valve discharge.

ASSE 1001 covers atmospheric vacuum breakers; ASSE 1002 covers dual check with intermediate vent; ASSE 1011 covers hose-bibb vacuum breakers.

ASSE 1012 covers pressure vacuum breakers; ASSE 1013 covers reduced pressure principle assemblies; ASSE 1015 covers double check valve assemblies.

ASSE 1020 covers pressure-type vacuum breakers for use on boiler feed lines; ASSE 1047 covers spill-resistant vacuum breakers.

ASSE 5110 is the professional qualification standard for cross-connection control surveyors; ASSE 5120 covers backflow prevention assembly testers.

The Safe Drinking Water Act and EPA regulations require public water systems to protect against cross-connections.

State and local plumbing codes and water supplier regulations establish testing intervals and installation requirements.

ASSE 6040 is the professional qualification standard for cross-connection control program administrators.

NFPA 13 and local fire codes govern backflow protection on fire sprinkler systems and standpipes.

A program includes authority, inspection, hazard assessment, device installation, testing, recordkeeping, and enforcement.

The water supplier must have legal authority to require cross-connection control through ordinance, rule, or service contract.

A cross-connection control program should identify all service connections and classify them by hazard level.

Program staffing includes a program administrator, surveyors, and certified testers.

The program should maintain a written policy, a hazard classification list, and a testing schedule.

Public education and outreach reduce accidental cross-connections and improve compliance.

Enforcement tools include notices, re-test orders, and service termination for noncompliance.

The program should be reviewed annually and updated when regulations or hazards change.

Premises isolation protects the public water system at the service connection; internal isolation protects the building's own plumbing.

Hazard assessment determines whether a connection is a health hazard, a non-health hazard, or no hazard.

Health hazards require an air gap or reduced pressure principle assembly; non-health hazards may use a double check valve assembly.

A survey should inspect all fixtures, equipment, and processes that could create a cross-connection.

Typical high-hazard premises include hospitals, mortuaries, car washes, chemical plants, and irrigation systems.

Typical low-hazard premises include office buildings and retail stores with no process water.

The surveyor should document each hazard and recommend the appropriate protection method.

Premises isolation is required when internal protection cannot adequately protect the public system.

Reduced pressure principle assemblies are tested with a differential pressure gauge and must hold a minimum 5 psi differential across the first check.

The RP relief valve must open at a differential of at least 2 psi and close at a differential of at least 5 psi.

A double check valve assembly is tested by checking that each check valve holds a minimum of 1 psi.

A pressure vacuum breaker is tested for the check valve closing and the air inlet opening.

Test results must be recorded on a standard test report form with gauge readings and pass/fail status.

Devices must be tested at installation, after repair, and at intervals set by the authority, commonly annually.

Annual inspection includes checking for leaks, corrosion, debris, and proper installation height.

A failed assembly must be repaired or replaced and retested before being returned to service.

Each device record should include location, type, size, make, model, serial number, and test history.

Test reports must be submitted to the water supplier within the time frame set by regulation.

Records should be retained for the period required by the authority, often at least five years.

Program evaluation metrics include the number of devices, test compliance rate, and number of violations.

A tracking system should flag devices due for testing and send reminders to property owners.

Trend analysis of test failures helps identify problem installations and prioritize inspections.

Annual reports to the governing body summarize program performance and recommend improvements.

Accurate records support enforcement actions and demonstrate due diligence in protecting public health.