§ 25-137. Definitions.

Air gap means the unobstructed vertical distance through the free atmosphere between the lowest point of the potable water outlet and the rim of the receiving vessel.

Auxiliary water system means any water system on or available to the premises other than the waterworks. These auxiliary waters may include water from a source such as wells, lakes, or streams; or process fluids; or used water. They may be polluted or contaminated or objectionable, or constitute an unapproved water source or system over which the water purveyor does not have control.

Backflow means the flow of water or other liquids, mixtures, or substances into a waterworks from any source or sources other than its intended source.

Backflow prevention by separation (separation) means preventing backflow by either an air gap or by physical disconnection of a waterworks by the removal or absence of pipes, fittings, or fixtures that connect a waterworks directly or indirectly to a nonpotable system or one of questionable quality.

Backflow prevention device (device) means any approved device intended to prevent backflow into a waterworks.

Backpressure backflow means backflow caused by pressure in the downstream piping which is superior to the supply pressure at the point of consideration.

Backsiphonage backflow means backflow caused by a reduction in pressure which causes a partial vacuum creating a siphon effect.

Consumer means a person who drinks water from a waterworks.

Consumer's water supply system (consumer's system) means the water service pipe, water distributing pipes, and necessary connecting pipes, fittings, control valves, and all appurtenances in or adjacent to the building or premises.

Containment means the prevention of backflow into a waterworks from a consumer's water supply system by a backflow prevention device or by backflow prevention by separation at the service connection.

Contaminant means any objectionable or hazardous physical, chemical, biological, or radiological substance or matter in water.

Cross connection means any connection or structural arrangement, direct or indirect, to the waterworks whereby backflow can occur.

Degree of hazard means either a high, moderate or low hazard based on the nature of the contaminant; the potential health hazard; the probability of the backflow occurrence; the method of backflow either by backpressure or by backsiphonage; and the potential effect on waterworks structures, equipment, and appurtenances used in the storage, collection, purification, treatment, and distribution of pure water.

Distribution main means a water main whose primary purpose is to provide treated water to service connections.

Division means the Commonwealth of Virginia Department of Health Office of Water Programs' Division of Water Supply Engineering.

Domestic use or usage means normal family or household use, including drinking, laundering, bathing, cooking, heating, cleaning and flushing toilets. (See appendix A for title 32.1, article 2, Code of Virginia, 1950, as amended).

Double gate-double check valve assembly means an approved assembly designed to prevent backsiphonage or backpressure backflow and used for moderate or low hazard situations, composed of two independently operating, spring-loaded check valves, tightly closing shutoff valves located at each end of the assembly and fitted with properly located test cocks.

Entry point means the place where water from the source is delivered to the distribution system.

Health hazard means any condition, device, or practice in a waterworks or its operation that creates, or may create, a danger to the health and well being of the water consumer.

Isolation means the prevention of backflow into a waterworks from a consumer's water supply system by a backflow prevention device or by backflow prevention by separation at the sources of potential contamination in the consumer's water supply system. This is also called point-of-use isolation. Isolation of an area or zone within a consumer's water supply system confines the potential source of contamination to a specific area or zone. This is called area or zone isolation.

Maximum contaminant level means the maximum permissible level of a contaminant in water which is delivered to the free-flowing outlet of the ultimate user of a waterworks, except in the cases of turbidity and VOCs, where the maximum permissible level is measured at each entry point to the distribution system. Contaminants added to the water under circumstances controlled by the user, except those resulting from corrosion of piping and plumbing caused by water quality, are excluded from this definition. Maximum contaminant levels may be either "primary" (PMCL) meaning based on health considerations or "secondary" (SMCL) meaning based on aesthetic considerations.

Plumbing fixture means a receptacle or device which is either permanently or temporarily connected to the water distribution system of the premises, and demands a supply of water therefrom; or discharges used water, waste materials, or sewage either directly or indirectly to the drainage system of the premises; or requires both a water supply connection and a discharge to the drainage system of the premises.

Pollution means the presence of any foreign substance (chemical, physical, radiological, or biological) in water that tends to degrade its quality so as to constitute an unnecessary risk or impair the usefulness of the water.

Pollution hazard means a condition through which an aesthetically objectionable or degrading material may enter the waterworks or a consumer's water system.

Premises means a piece of real estate, house or building and its land.

Pressure vacuum breaker means an approved assembly designed to prevent backsiphonage backflow and used for high, moderate, or low hazard situations, composed of one or two independently operating, spring-loaded check valves; an independently operating, spring-loaded air-inlet valve; tightly closing shutoff valves located at each end of the assembly; and fitted with properly located test cocks.

Process fluids means any kind of fluid or solution that may be chemically, biologically, or otherwise contaminated or polluted which would constitute a health, pollution, or system hazard if introduced into the waterworks. This includes, but is not limited to:

1.

Polluted or contaminated water,

2.

Process waters,

3.

Used water, originating from the waterworks, which may have deteriorated in sanitary quality,

4.

Cooling waters,

5.

Contaminated natural waters taken from wells, lakes, streams, or irrigation systems,

6.

Chemicals in solution or suspension, and

7.

Oils, gases, acids, alkalis, and other liquid and gaseous fluid used in industrial or other processes, or for firefighting purposes.

Pure water or potable water means water fit for human consumption and domestic use which is sanitary and normally free of minerals, organic substances, and toxic agents in excess of reasonable amounts for domestic usage in the area served and normally adequate in quantity and quality for the minimum health requirements of the persons served.

Reduced pressure principle backflow prevention device (RPZ device) means an approved assembly designed to prevent backsiphonage or backpressure backflow used for high, moderate, or low hazard situations, composed of a minimum of two (2) independently operating, spring-loaded check valves together with an independent, hydraulically operating pressure differential relief valve located between the two (2) check valves. During normal flow and at the cessation of normal flow, the pressure between these two (2) checks shall be less than the supply pressure. The unit must include tightly closing shutoff valves located at each end of the assembly and be fitted with properly located test cocks.

Service connection means the point of delivery of water to a customer's building service line as follows:

1.

If a meter is installed, the service connection is the downstream side of the meter;

2.

If a meter is not installed, the service connection is the point of connection to the waterworks.

3.

When the water purveyor is also the building owner, the service connection is the entry point to the building.

System hazard means a condition posing a threat of or actually causing damage to the physical properties of the waterworks or a consumer's water supply system.

Used water means water supplied from the waterworks to a consumer's water supply system after it has passed through the service connection.

Water supply means the water that shall have been taken into a waterworks from all wells, streams, springs, lakes, and other bodies of surface water (natural or impounded), and the tributaries thereto, and all impounded groundwater, but the term "water supply" shall not include any waters above the point of intake of such waterworks.

Waterworks means a system that serves piped water for drinking or domestic use to (1) the public, (2) at least fifteen (15) connections, or (3) an average of twenty-five (25) individuals for at least sixty (60) days out of the year. The term "waterworks" shall include all structures, equipment, and appurtenances used in the storage, collection, purification, treatment, and distribution of pure water except the piping and fixtures inside the building where such water is delivered (see title 32.1, article 2, Code of Virginia, 1950, as amended).

Waterworks owner means an individual, group of individuals, partnership, firm, association, institution, corporation, government entity, or the federal government which supplies or proposes to supply water to any person within this state from or by means of any waterworks (see title 32.1, article 2, Code of Virginia, 1950, as amended).

TABLE 1—DETERMINATION OF DEGREE OF HAZARD

Premises with the following conditions shall be rated at the corresponding degree of hazard.

High Hazard	The contaminant is toxic, poisonous, noxious or unhealthy.
	In the event of backflow of the contaminant, a health hazard would exist.
	A high probability exists of a backflow occurrence either by backpressure or by backsiphonage.
	The contaminant would disrupt the service of piped water for drinking or domestic use.
	Examples—Sewage, used water, nonpotable water, auxiliary water systems and toxic or hazardous chemicals.
Moderate Hazard	The contaminant would only degrade the quality of the water aesthetically or impair the usefulness of the water.
	In the event of backflow of the contaminant, a health hazard would not exist.
	A moderate probability exists of a backflow occurrence either by backpressure or by backsiphonage.
	The contaminant would not seriously disrupt service of piped water for drinking or domestic use.
	Examples—Foodstuff, nontoxic chemicals and nonhazardous chemicals.
Low Hazard	The contaminant would only degrade the quality of the water aesthetically.
	In the event of backflow of the contaminant, a health hazard would not exist.
	A low probability exists of the occurrence of backflow.
	Backflow would only occur by backsiphonage.
	The contaminant would not disrupt service of piped water.
	Examples—Foodstuff, nontoxic chemicals and nonhazardous chemicals.

 

(Ord. No. 04-1700-769, § 1, 11-11-04)

(Ord. No. 04-1700-769, § 1, 11-11-04)