Frequently Asked Questions
Cross-Connection Control and
Backflow Prevention
What
is backflow?
Backflow
is a reversal of the flow of water from the normal direction. When
backflow occurs, the water in your plumbing or irrigation system
flows back through the meter and into the public water system’s
distribution pipes.
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What
is a cross-connection?
A
cross-connection is a DIRECT, INDIRECT, or POTENTIAL connection
between Central Arkansas Water's (CAW) distribution system and another
system of questionable quality.
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What
causes backflow?
Backflow
may occur when there is a loss of system pressure or the customer’s
water pressure increases above that of CAW's distribution system.
Two
types of backflow are BACK-SIPHONAGE and BACK-PRESSURE.
BACK-SIPHONAGE
occurs when low or negative pressure on the supply side of the system
causes the reversal of the normal flow of water. Back-siphonage
may be caused on the supply side of the system when there is a break
on a water main, during firefighting, or when a motorist hits a
fire hydrant and causes damage.
BACK-PRESSURE
occurs when the water pressure within the customer's plumbing system
exceeds the pressure of the water utility’s distribution system.
Backpressure may be caused by differences in elevation, a booster
pump, or a chemical injection system.
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What
is the primary health risk?
The
primary hazard associated with cross-connections is contaminated
water being drawn back into the public water system. If consumed,
the contaminated water can cause serious illness in humans.
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How
common is a backflow occurrence?
The
Arkansas Department of Health has documented numerous cases of backflow
on public water systems in the state. In documented incidents, serious
illness almost always has been the result. In addition, backflow
incidents are not always documented; therefore, it is unknown just
how many illnesses occur and how often backflow incidents occur.
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What
can be done to protect public water system from cross-connections?
In
1995, the Arkansas Department of Health (ADH) amended Act 96 of
1913 (Rules and Regulations Pertaining to Public Water Systems)
and mandated that all public water utilities institute a Cross-Connection
Control Program. The intent of the program is to locate, identify,
and eliminate, or protect against, all potential cross-connections.
Customers found to have a cross-connection or a potential cross-connection
must be isolated from the public water system. CAW requires the
installation of a Reduced Pressure Zone Assembly (RPZA) on all water
services where a potential cross-connection may exist. RPZAs, unlike
older non-testable devices such as swing check valves, dual check
valves, and atmospheric vacuum breakers, are testable in place to
assure proper operation.
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What
type of device is needed for my level of hazard?
CAW
requires the installation of an RPZA on the water service of all
facilities that pose a potential hazard to the public water supply.
State
regulations also require the protection of the public water system
from the potential of backflow from Fire Sprinkler Systems. The
installation of a Double Detector Check Valve Assembly (DDCVA) is
adequate unless the Fire Sprinkler System has additives or a secondary
water source is present. In this situation, we require the installation
of an RPZA.
Underground
Irrigation Systems pose a high health hazard and also require the
installation of an RPZA.
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How
does CAW determine the need for devices?
All
commercial and industrial customers within the CAW service area
periodically will receive a survey questionnaire in the mail. We
ask that you complete and return the Survey Form to us. CAW then
will determine whether state regulations require the installation
of an assembly. In some cases, it may be necessary for CAW personnel
to perform an on-site inspection. If the survey requires an on-site
inspection, a service charge is applicable.
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What
facilities typically have hazards that require an RPZA Assembly?
| Air
Conditioning Cooling Towers |
Metal
Plating Plants |
| Auto
Repair, Paint & Body Shops |
Medical
Facilities |
| Beauty,
Barbers & Nail Salons |
Multi-water Services |
| Car
& Truck Wash Facilities |
Recycling
Facilities |
| Commercial
Laundries |
Restricted
Facilities |
| Facilities
with Swimming Pools |
Restaurants
& Clubs |
| Farms
& Agricultural Operations |
Schools |
| Film
Processing Laboratories |
Sewer
Plants |
| Food
Processing |
Sites
with Pumps |
| Funeral
Homes |
Sites
with Chemicals |
| Health
Clubs & Spas |
Tattoo
& Piercing |
| Industrial
& Manufacturing |
Testing
Laboratories |
| Landfills
& Dumps |
Veterinarian
& Kennels |
| Lawn
Irrigation Systems |
Zoos
& Animal Shelters |
For a complete listing please see the Cross-Connection Manual Section
4.2 RPZA CONTAINMENT
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What
are the installation requirements?
Only
licensed plumbers may install assemblies. If the assembly is on
a Fire Protection System, then only personnel licensed by the State
of Arkansas and holding a Registered Mechanical Engineer license
or employed by a company licensed by the Fire Protection Licensing
Board may install assemblies. Other wise the vent of the relief
valve on the RPZA shall be between 12" and 30" above ground.
Horizontal clearance shall be 30" between the assembly and
an adjacent wall, 12" on the opposite side, 8" at each
end, 6" above the highest point, and 12" underneath the
assembly. Assemblies 3" or larger in diameter shall have adequate
support and all installations must have a strainer and blow-off.
An assembly cannot be mounted in a vertical position unless it specifically
designed for this orientation.
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Where
must I locate the RPZA Assembly?
Installation
of an RPZA other than a Fire Service must be above ground on the
customer's side of the meter and before the first outlet or point
of use. If the installation is inside a building, it must be in
a location protected from freezing, provided there is adequate drainage
for discharge.
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How
do I protect my assembly in freezing weather?
Permanent
outdoor assemblies must be in an approved enclosure (American Society
of Sanitary Engineering Standard 1060).
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What
are the requirements for testing the assembly?
The
ADH mandates the testing of assemblies within 10 days of installation
and annually thereafter. The department requires the testing of
assemblies on irrigation systems each spring or with placement back
in service.
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Who
has authorization to test the assembly?
Only
personnel with Assembly Tester Technician certification from the
ADH may test backflow assemblies in the CAW service area. Only personnel
with a valid license from the Arkansas Fire Protection Licensing
Board and the AHD may test assemblies on Fire Protection Systems.
A listing of Certified Assembly Tester Technicians may be found
in the Yellow Pages under "Backflow Prevention Devices &
Services," "Sprinklers - Lawn and Garden," and the
plumbing section. The Arkansas Department
of Health and Backflow
Prevention Association of Arkansas websites provide a list of
testers.
In
addition, a partial list of local certified testers is available
at Central Arkansas Water .
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Who
is responsible for the cost of installation, testing, and maintenance?
Under
the Arkansas State Plumbing Code, the homeowner has responsibility
for all costs associated with the installation, testing, and maintenance
of backflow assemblies on the customer’s premises.
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