The purpose of this chapter is to eliminate
cross-connections and to protect the public health. This chapter provides
for establishment and enforcement of a program of cross-connection
control and backflow prevention in accordance with the Commonwealth
of Virginia, State Board of Health, Waterworks Regulations 1974, as
amended.
As used in this chapter, the following terms
shall have the meanings indicated:
AIR GAP SEPARATION
The unobstructed vertical distance through the free atmosphere
between the lowest opening from any pipe or faucet supplying pure
water to a tank, plumbing fixture or other device and the rim of the
receptacle.
AUXILIARY WATER SYSTEM
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
The flow of water or other liquids, mixtures or substances
into the distribution piping of a waterworks from any source or sources
other than its intended source.
CONSUMER
Any person who drinks water from a waterworks.
CONSUMER'S WATER SYSTEM
Any water system located on the consumer's premises, supplied
by or in any manner connected to a waterworks.
CONTAMINANT
Any objectionable or hazardous physical, chemical, biological
or radiological substance or matter in water.
CROSS-CONNECTION
Any connection or structural arrangement, direct or indirect,
to the waterworks whereby backflow can occur.
DEGREE OF HAZARD
The level of health hazard, as derived from an evaluation
of the potential risk to health and the adverse effect upon the waterworks.
DISTRIBUTION MAIN
A water main whose primary purpose is to provide treated
water to service connections.
DOMESTIC USE OR USAGE
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
An approved assembly composed of two single independently
acting check valves, including tightly closing shutoff valves located
at each end of the assembly, and petcocks and test gauges for testing
the water tightness of each check valve.
ENTRY POINT
The place where water from the source is delivered to the
distribution system.
HEALTH HAZARD
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.
MAXIMUM CONTAMINANT LEVEL
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 prior 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
A receptacle or device which is either permanently or temporarily
connected to the water distribution system of the premises and which
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
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
A condition through which an aesthetically objectionable
or degrading material may enter the waterworks or a consumer's water
system.
REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION DEVICE (RPZ DEVICE)
A device containing a minimum of two independently acting
check valves, together with an automatically operated pressure differential
relief valve located between the two check valves. During normal flow
and at the cessation of normal flow, the pressure between these two
checks shall be less than the supply pressure. In case of leakage
of either check valve, the differential relief valve shall operate
to maintain this reduced pressure by discharging to the atmosphere
at less than the supply pressure. The unit must include tightly closing
shut-off valves located at each end of the device, and each device
shall be fitted with properly located test cocks. These devices must
be of the approved type.
SERVICE CONNECTION
The point of delivery of water to a customer's building service
line as follows:
A.
If a meter is installed, the service connection
is the downstream side of the meter.
B.
If a meter is not installed, the service connection
is the point of connection to the waterworks.
C.
When the purveyor is all the building owner,
their service connection is the entry point to the building.
PREMISES
A piece of real estate, house or building and its land.
PROCESS FLUIDS
Any kind of fluid or solution which may be chemically, biologically
or otherwise contaminated or polluted which would constitute a health,
pollutional or system hazard if introduced into the waterworks. This
includes, but is not limited to:
A.
Polluted or contaminated water;
C.
Used water, originating from the waterworks
which may have deteriorated in sanitary quality;
E.
Contaminated natural waters taken from wells,
lakes, streams or irrigation systems;
F.
Chemical in solution or suspension; and
G.
Oils, gases, acids, alkalis and other liquid
and gaseous fluid used in industrial or other processes or for fire-fighting
purposes.
PURE WATER OR POTABLE WATER
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. (See Title 32.1, Article
2, Code of Virginia 1950, as amended.)
SYSTEM HAZARD
A condition posing an actual or threat of damage to the physical
properties of the waterworks or a customer's water supply system.
USED WATER
Any water supplied by a water purveyor from the waterworks
to a consumer's water supply system after it has passed through the
service connection.
WATER SUPPLY
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. (See Title 32.1, Article
2, Code of Virginia 1950, as amended.)
WATER SUPPLY SYSTEM
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.
WATERWORKS
A system that serves piped water for drinking or domestic
use to the public, at least 15 connections or an average of 25 individuals
for at least 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 OR WATER PURVEYOR
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.) For this chapter it is the
City of Galax Water Plant.
The type of protection required shall depend on the degree of hazard which exists or may exist and on the method of potential backflow. Backflow occurs either by back pressure or by backsiphonage. The degree of hazard, either high, moderate or low, is based on the nature of the contaminant, the potential of the health hazard, the probability of the backflow occurrence and the effect on waterworks structures, equipment and appurtenances used in the storage, collection, purification, treatment and distribution of pure water.
Table 1 shall be used as a guide to determine the degree of hazard for any situation.
A. Air gaps give the highest degree of protection and
shall be used whenever practical to do so in high-hazard situations
subject to back pressure.
B. An air gap separation and a reduced pressure principle
backflow prevention device will protect against back pressure when
operating properly.
C. Vacuum breakers will not protect against back pressure,
but will protect against backsiphonage when operating properly. Vacuum
breakers may be used in high-hazard situations subject to backsiphonage
only.
D. Backflow prevention devices consisting of dual independent
check valves with or without an intermediate atmospheric vent shall
only be used in low-hazard situations.
E. Barometric loops are not acceptable.
F. An interchangeable connection or change-over device
is not acceptable.
G. Reduced pressure principle type backflow preventers
shall not be installed in pits or areas subject to flooding.