The Town shall be responsible for the protection of the public
potable water distribution system from contamination or pollution
due to the backflow or back-siphonage of contaminants or pollutants
through the water service connection.
As used in this article, the following terms shall have the
meanings indicated:
APPROVED
Accepted by the Town as meeting an applicable specification
stated or cited in this regulation, or as suitable for the proposed
use.
AUXILIARY WATER SUPPLY
Any water supply on or available to the premises other than
the Town's public potable water supply.
BACKFLOW
The flow of water or other liquids, mixtures or substances
under positive or reduced pressure in the distribution pipes of a
potable water supply from any source other than its intended source.
BACKFLOW PREVENTER
A device or means designed to prevent backflow or back-siphonage.
Most commonly categorized as air gap, reduced pressure principle device,
double check valve assembly, pressure vacuum breaker, atmosphere vacuum
breaker, hose bib vacuum breaker, residential dual check, double check
with intermediate atmospheric vent, and barometric loop.
A.
AIR GAPA physical separation sufficient to prevent backflow between the free-flowing discharge end of the potable water system and any other system. Physically defined as a distance equal to twice the diameter of the supply side pipe diameter but never less than one inch.
B.
ATMOSPHERIC VACUUM BREAKERA device which prevents back-siphonage by creating an atmospheric vent when there is either a negative pressure or subatmospheric pressure in a water system.
C.
BAROMETRIC LOOPA fabricated piping arrangement rising at least 35 feet at its topmost point above the highest fixture it supplies. It is utilized in water supply systems to protect against back-siphonage.
D.
DOUBLE CHECK VALVE ASSEMBLYIn assembly of two independently operating spring-loaded check valves with tightly closing shutoff valves on each side of the check valves, plus properly located test cocks for the testing of each valve.
F.
HOSE BIB VACUUM BREAKERA device which is permanently attached to a hose bib and which acts as an atmospheric vacuum breaker.
G.
PRESSURE VACUUM BREAKERA device containing one or two independently operated spring-loaded check valves and an independently operated spring loaded air inlet valve located on the discharge side of the check or checks. Device includes tightly closing shutoff valves on each side of the check valves and properly located test cocks for the testing of the check valve(s).
H.
REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTERAn assembly consisting of two independently operating check valves with an automatically operating differential relief valve located between the two check valves, tightly closing shutoff valves on each side of the check valves plus properly located test cocks for the testing of the check valves and the relief valve.
I.
RESIDENTIAL DUAL CHECKAn assembly of two spring-loaded, independently operating check valves without tightly closing shutoff valves and test cocks. Generally employed immediately downstream of the water meter to act as a containment device.
BACKPRESSURE
A condition in which the owner's system pressure is
greater than the supplier's system pressure.
BACK-SIPHONAGE
The flow of water or other liquids, mixtures or substances
into the distribution pipes of a potable water supply system from
any source other than its intended source caused by the sudden reduction
of pressure in the potable water supply system.
CONTAINMENT
A method of backflow prevention which requires a backflow
prevention preventer at the water service entrance.
CONTAMINANT
A substance that will impair the quality of the water to
a degree that it creates a serious health hazard to the public, leading
to poisoning or the spread of disease.
CROSS-CONNECTION
Any actual or potential connection between the public water
supply and a source of contamination or pollution.
FIXTURE ISOLATION
A method of backflow prevention in which a backflow preventer
is located to correct a cross-connection at an in-plant location rather
than at a water service entrance.
MDE
Maryland Department of the Environment Water Supply Program.
OWNER
Any person who has legal title to a property served by the
Town's water system.
PERMIT
A document issued by the Town which allows the use of a backflow
preventer.
POLLUTANT
A foreign substance that, if permitted to get into the public
water system, will degrade its quality so as to constitute a moderate
hazard or impair the usefulness or quality of the water to a degree
which does not create an actual hazard to the public health but which
does adversely and unreasonably effect such water for domestic use.
SUPERINTENDENT
The state-licensed Superintendent, or his delegated representative,
in charge of the operation of the Town's water supply and distribution
system who is vested with the authority and responsibility for the
implementation of a cross-connection control program and the enforcement
of the provisions of the Cross-Connection Control Program.
TOWN
Town of North Beach, an incorporated municipality located
in Calvert County, Maryland.
WATER SERVICE ENTRANCE
That point in the owner's water system beyond the sanitary
control of the Town; generally considered to be the outlet end of
the water meter and always before any unprotected branch.
The Town recognizes the threat to the public water system arising
from cross-connections. All threats will be classified by degree of
hazard and will require the installation of approved reduced pressure
principle backflow prevention devices or double check valves.
The Town shall not permit a cross-connection within the public
water supply system unless it is considered necessary and it cannot
be eliminated.
A. Cross-connection permits that are required for each backflow prevention
device are obtained from the Town. A fee will be charged for the initial
permit and any renewals of the permit.
B. Town permits shall be renewed every two years and are nontransferable.
Permits are subject to revocation and become immediately revoked if
the owner should so change the type of cross-connection or degree
of hazard associated with the service.
Any existing backflow preventer shall be allowed by the Town
to continue in service unless the degree of hazard is such as to supersede
the effectiveness of the present backflow preventer or result in an
unreasonable risk to the public health. Where the degree of hazard
has increased, as in the case of a residential installation converting
to a business establishment, any existing backflow preventer must
be upgraded to a reduced pressure principle device or a reduced pressure
principle device must be installed in the event that no backflow device
was present.
The Town will adopt and periodically publish a list of fees
or charges associated with this Cross-Connection Control Program.
A. Residential dual check.
(1)
Effective the date of the acceptance of this Cross-Connection
Control Program for the Town, all new residential buildings will be
required to install a residential dual check device immediately downstream
of the water meter. Installation of this residential dual check device
on a retrofit basis on existing service lines will be instituted as
a time and cost permit. This retrofit shall be completed by the Town.
(2)
The owner must be aware that installation of a residential dual
check valve results in a potential closed plumbing system within his
residence. As such, provisions may have to be made by the owner to
provide for thermal expansion within his closed loop system, i.e.,
the installation of thermal expansion devices and/or pressure relief
valves.
B. Strainers. The Town recommends that all new retrofit installations
of reduced pressure principle devices and double check valve backflow
preventers include the installation of strainers located immediately
upstream of the backflow device. The installation of strainers will
preclude the fouling of backflow devices due to both foreseen and
unforeseen circumstances occurring to the water supply system such
as water main repairs, water main breaks, fires, periodic cleaning
and flushing of mains, etc., that may stir up debris within the water
main that will cause fouling of backflow devices installed without
the benefit of strainers.