Backflow Related Terms

Backflow is a reversal of the normal flow of a liquid or gas.

A cross-connection is a link between a potable water system and a non-potable system.

A permanent cross-connection is a link between the potable water supply and any other non-potable system designed to remain in place.

A temporary cross-connection is a link between the potable water supply and any other non-potable system created with removable sections, swivel or change-over devices, garden hoses, and other non-permanent methods.

A direct cross-connection is a link between the potable water supply and any other non-potable system that is subject to both backsiphonage and backpressure.

An indirect cross-connection is a temporary link between the potable water supply and any other non-potable system that is subject to backsiphonage only.

Non-potable water is water that is contaminated by any liquid, gas or solid that can be diluted, dissolved, suspended or mixed with water that adversely affects the quality of the water.

A substance is a high hazard (health hazard) if it can adversely affect human health and safety.

Low hazards (non-health hazards) do not affect public health.

A pollutant is a substance that deteriorates the aesthetic quality of water or other materials but is not harmful to health.

The two types of backflow are backpressure and backsiphonage.

Backpressure occurs when the customer?s pressure exceeds the supply pressure.

Backsiphonage occurs when the supply line pressure falls below atmospheric pressure.

The Safe Drinking Water Act (SDWA) was established in 1974.

Primacy means that the states have primary enforcement responsibility.

Biological pollutants (low hazards) are agents that do not cause disease, but that do decrease the aesthetic quality of water.

Biological contaminants (high hazards) are agents that can cause disease.

Chloramines are created when ammonia is used in combination with chlorine.

Chemical pollutants are substances that do not pose a public health threat, but reduce the aesthetic quality of the water.

Chemical contaminants are substances that pose a threat to public health.

Contaminants added to the water by circumstances under the control of the consumer are not the responsibility of the supplier of water, unless the contaminants result from corrosion of piping and plumbing resulting from the quality of the water supplied.

State regulations must equal or exceed the federal regulations.

No contaminant which creates or has the potential to create an imminent and substantial danger to the public shall be introduced into a public water system.

Upon discovery of a prohibited cross-connection, public water systems shall either eliminate the cross-connection by installation of an appropriate backflow prevention device acceptable to the Department or shall discontinue service until the contaminant source is eliminated.

Those involved in backflow prevention should endeavor to achieve the highest level of protection possible, using sound judgment in order to avoid the hazards associated with backflow.

The water purveyor is responsible for supplying water that is safe and wholesome to the public.

The isolation method provides internal protection by having a backflow-preventer at each cross-connection within a consumer's property.

Containment, or service protection, is the term used when backflow prevention assemblies are used to keep contaminants from entering the distribution system from a water consumer's facility.

Containment (service protection) backflow preventers are installed at the meter.

The basic responsibility of the consumer is to prevent contaminants or pollutants from entering the public water system.

Approved testers should be required to have a business license and insurance coverage.

Code of Conduct

Certified testers placed on an approved testers list by the local authority should have their credentials checked, obtain a business license, have insurance coverage, and sign a Code of Conduct document.

The local authority should be comfortable that the tester requesting placement on the approved list is a competent tester. Some authorities will require the applicant take a local examination. Not all training facilities teach the same information or require that the tester actually learn the field test procedures to be certified.

It is highly recommended that the local authority create a Code of Conduct for the certified tester to sign. A certified tester who is placed on a list of approved testers that is sent to the customer is a contractor representing the local authority. Testers who do not provide good service to the customers should be removed from the approval list.


This information taken from "Backflow Prevention, Theory and Practice" 2nd Edition
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