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Cross Connection
And Backflow Prevention Program
And Its Impact on You!
Adopted in
compliance with Chapter 341, Subchapter C, of the Texas Health
and Safety Code & Section 290 Rules and Regulations, Texas
Commission on Environmental Quality.
Proudly serving
the Community of Dickinson since 1938.
Water
Supply Protection Program
Galveston County
W.C.I.D. No. 1 is adopting a mandatory cross-connection control
program, in compliance with Chapter 341, Subchapter C, of
the Texas Health and Safety Code and Section 290 of the Rules
and Regulations for Texas water systems governed by the Texas
Commission on Environmental Quality. These state laws
are a result of the Federal Safe Drinking Water Act.
These rules and
regulations have made it the responsibility of the local water
provider to enforce the cross connection laws. It is
our intent to work with our residential and commercial customers
in order that they comply with the following requirements
in a timely manner. Section 290.44(h)(1) of the "Texas
Rules and Regulations for Public Water Systems" states
that: "No water connection from any public drinking water
supply system shall be made to any establishment where an
actual or potential contamination or system hazard exists
without an air gap separation between the drinking water supply
and the source of potential contamination."
No facility
connection to a public water system is grandfathered from
these above requirements. It would be nice
if drinking water contamination never, occurred, then no person
would be adversely affected. Unfortunately, an ever
growing number of serious incidents have occurred. Liability
exists when innocent are harmed by contaminated water supplies.
As water system providers, public water supply systems have
a responsibility to protect the water supply.
A very important part of this protection involves cross-connection
control.
Local Authority:
The Water District has adopted a Cross-Connection Control
and Prevention Ordinance. The complete text of that
ordinance is available to you at either the Water District
Office or at City Hall.
Potential
Cross Connections To The Public Water System Can Occur At
The Following Locations:
Phase 1 High
Health Hazard Locations
Auxilliary
Water Systems (Private Water Wells)
*Barber Shops
*Beauty Shops
Boilers
Building Using Booster Pumps
Chemical Plants
Commercial Establishments Serving Food/ Drinks
Convenience Stores
Dentist Offices
Electronic Plating, Film Processing & Metal
Finishing Facilities
Facilities having Carbonated Fountain Machines
Funeral Homes
High Rise Buildings |
Hospitals
*Laundromats
Medical Clinics
Nursing Home Facilities
Oil & Gas Facilities
*Piers and Docks
*Plant Nurseries
Residences
Restaurants
Sanitariums, Morgues
*Schools (Public and Private)
Veterinary Clinics
Wastewater Plants
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Phase
II: Low Health Hazard Locations
Apartments
*Barber Shops
*Beauty Shops
Churches and Synagogues
Lawn Sprinkler Systems
*Laundromats
*Piers and Docks
*Plant Nurseries
Residences
*Schools (Public and Private) |
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* Denotes possible
high health or low health concerns. The determination
will be made by the Water Supply Specialist representing the
District.
Enforcement
Action Required
Water service
will be discontinued or disconnected after reasonable notice
to the consumer if a violation exists on their premises.
Additional precautionary measures will be taken as are deemed
necessary to eliminate any danger to the potable water system.
Water service will not be restored until the danger has been
eliminated in compliance with Southern Standard Plumbing Code
and the District's Cross- Connection Control Ordinance.
If a dispute arises
with the Plumbing Inspector or the District's Water Supply
Specialist concerning the Cross-Connection Control Ordinance,
then the consumer has the right of appeal to the Galveston
County W.C.I.D. No. 1, Board of Directors.
Actions that will
be taken by Water District will include:
Inspect new and existing water
services where high hazards may likely exist.
Require all water users to properly install and maintain cross-connection
control devices when actual or potential hazards exist.
Require actual inspections and testing of mechanical devices
in high health hazard services (at customer's expense).
Encourage water user's to notify the Water District about
existing hazards or changes that may affect the hazard potential.
Develop and maintain a record system documenting cross-connection
hazards, controls, mechanical devices, and inspection and
testing program. (Records will be maintained by Water District.)
What is a cross
connection? What is backflow? What is back siphonage? What
is back pressure? Why do I need to worry about it? These questions
are asked by our customers everyday.
Cross connection
control is, simply a program that is designed to take the
safeguards necessary to protect one of the world's most essential
assets...water. Only through education and the combined
cooperation, of the public and the water district, can we
insure a safe supply of drinking water.
After many documented
cases of drinking water being contaminated or polluted, by
both commercial and residential sources, rules and regulations
were formulated and put into place. The single most significant
problem hampering the elimination of cross-connections and
backflow, is that little has been done to educate the water
consumer about problems associated with cross-connections,
backflow and back pressure.
Cross-Connection
Control Is An Essential Component Of Safe Drinking Water Systems
Plumbing system
cross connections, which have been defined as existing or
potential connections between potable, safe to drink, and
non-potable water supplies, continue to be a serious potential
public health hazard across the nation. Waterborne disease
outbreaks have been controlled, but not yet eliminated.
Properly installed and maintained backflow prevention devices
are critical elements of safe drinking water systems in our
communities and workplaces.
There have been
numerous historical, as well as recent incidents, where the
backflow or back siphonage of contaminated water through a
cross-connection has been the agent for contaminating a community's
drinking water system, resulting in illness, the spread of
disease, and death, along with severe economic repercussions.
The cross-connection
problem is an ongoing dynamic one, because potable water piping
systems are continually being installed and altered,
while water using systems and equipment which can contaminate
a drinking water system often continue to be connected without
appropriate, properly installed backflow preventer valves.
An example of
a cross-connection is a direct link between a household water
line and a contaminated source, such as an ordinary garden
hose, toilet tank, pesticides applicants, domestic sewage
systems.
Types
Of Hazards From Cross-Connections
Most household
cross connections are created by hoses. Under certain
conditions, the flow in household water lines can reverse
and siphon contaminants into the water supply. For example,
using a garden hose to spray pesticides or fertilizers is
normally harmless, but if the municipality's water system
is interrupted while you are spraying, you may have a problem.
If water main
pressure is reduced due to water main break or nearby fire
fighting, a back siphonage effect is created. This can
draw water from your garden hose into your home water supply.
So, if you have a pesticide or fertilizer sprayer attached
to your garden hose, the chemicals can contaminate your water
supply.
There Is A
Solution!
You can easily
prevent back siphonage by installing inexpensive safety devices
or taking a few simple precautions.
1. Antisiphonage
ballcocks: Toilet tanks contain a ballcock device which allows
water into the tank after flushing. Older style ballcocks
do not have an anti-siphon feature and can allow water from
the toilet tank to backflow into your drinking water line
(figure 1). A simple anti-siphon ballcock (figure 2)
installed with a one-inch air gap above the overflow tube
will prevent contaminated tank water from entering your water
supply.
2. Hose connection
vacuum breakers: You can also prevent back siphonage by using
an inexpensive, easy to install hose connection vacuum breaker
(figure 3). This one-way valve allows water to flow
from the tap, but not back in. Drainable vacuum breakers
should be installed on all those connections which could freeze.
3. Air gaps: Leave
a gap of at least one inch or two times the pipe diameter
(whichever is greater) between the end of a hose and a source
of contamination. This eliminates a link between the
two. Never leave a hose where it can suck contaminants
back into the drinking water supply, such as in a swimming
pool, bathtub, sink or fish tank.
The term backflow
means any unwanted flow of used non-potable water or substance
from any source into the potable water distribution system.
In a backflow condition, water is flowing in the opposite
direction of its normal flow. With the direction of
flow reversed, due to a change in pressures, backflow can
allow pollutants or contaminants to enter the potable water
distribution system. The change in pressures or reverse
pressure gradient that allows backflow to occur may be due
to either a loss of pressure in the supply main (back siphonage)
or by the flow from a customer's pressurized system through
an unprotected cross-connection (back pressure). Back
siphonage can be created by any change of system wherein the
pressure at the supply point becomes lower than the pressure
at the point of use. When this happens in an unprotected
situation, the water at the point of use will be siphoned
back into the system and potentially pollute or contaminate
the customer's system. It is also possible for the "dirty"
water to continue to backflow into the public distribution
system. Back pressure conditions often occur as a result
of the use of high pressure booster pumps or recirculating
pumps. Booster pumps are used primarily in commercial
applications to recirculate hot water and in multi-story buildings.
The use of this type of pump can easily increase the pressure
above that of the supply main. Thus, if there is a pathway,
whereby this pressurized water can enter the potable distribution
system , there will be a hazard of back pressure.
Examples
Of Backflow Incidents
Backflow from
Garden Hoses
The most common
cause of backflow is a cross-connection from a garden hose.
It is estimated that there are over 10,000 cross-connections
in Texas from garden hoses every day. (Source: TCEQ)
Backflow
from Residences
Lawn irrigation systems can also cause backflow conditions
to occur. In 1991, two homeowners in Michigan found
parasitic worms in their water along with rust and other debris.
This was caused when the atmospheric vacuum breaker on one
of the homeowner's residential irrigation system had malfunctioned
because the device's air inlet valve had stuck to the device's
air inlet port. At the same time that the vacuum breaker failed,
there was a water main break causing a vacuum in the public
water supply system. The vacuum in the public water
system pulled some water - and some worms and debris from
the irrigation system into the public water system. (Source:
AWWA)
Backflow
from Clinics or Hospitals
In 1993, a clinic in North Carolina complained of a strange,
bitter taste and strong chemical odor to its water.
They discovered that chemicals from a mixer used in x-ray
development at the clinic had backflowed into the clinic's
water system. The mixer combined chemicals with potable
water supplied by a garden hose connected to a hose bibb.
Someone at the clinic had submerged the end of the garden
hose in the mixer, thus creating an indirect cross-connection.
As a result the chemicals in the mixer were backsiphoned through
t he garden hose
into the clinic's potable water supply. (Source: AWWA)
Backflow
from Car Washes
Many residents in Seattle, Washington began complaining that
their water was "gray-green and slippery", "muddy",
or "soapy" in February of 1979. When the water
was analyzed, the tests indicated that the water had been
contaminated with a detergent solution. The source of
the detergent solution was traced to the recycled wash/rinse
water at a carwash that had backflowed in to the public water
system. The backflow event was apparently caused because
a high-pressure pump that normally pumped recycled wash/rinse
water to the initial scrubber cycle of the car wash broke
down. After the high pressure pump broke down, the workers
kept the car wash running by connecting a two inch hose between
the piping in the rinse cycle of the car wash (that used potable
water) to the piping of the scrubber cycle. Once the
broken high pressure pump was repaired, the temporary hose
was not removed. Although no one at the car wash realized
it, the high pressure pump had forced a large quantity of
recycled wash/rinse water into the public water system.
The car wash was ordered to install a reduced pressure backflow
prevention assembly to the public water service connection
at the car wash. (Source: USEPA)
Backflow
from Veterinary Office
The City of Calgary,
Canada received complaints about poor tasting water in June
of 1983. After collecting samples and analyzing them,
the City found detectable traces of E Coli. An investigation
of possible sources revealed that the Veterinary office had
several cross-connections. The Veterinary office was
ordered to install backflow prevention assemblies. (Source:
AWWA)
How
Can Backflow Be Prevented?
There are nine
(9) distinct types of piping or mechanical assemblies, which
are considered to be backflow prevention assemblies: but it
must be stressed that these are not all equally acceptable
as protection against all hazard types.
The degree of
hazard must be accessed along with the type of cross-connection
present to determine which type of backflow prevention assembly
is most suited to the situation. The official determining
the type of device required is the local Plumbing Inspector
or the District's Certified Inspector. The State of
Texas develops criteria for officials to follow for determining
proper device.
Devices
Used To Prevent Backflow
air gaps
barometric loops
atmospheric vacuum breakers
hose bibb vacuum breakers
pressure vacuum breaker assembly
dual check valves
double check with atmospheric vent
double check valve assembly
reduced pressure zone assembly
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Example:
hose bibb vacuum breaker assembly for residential
use.
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| Example:
reduced pressure zone assembly for commercial use.
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Example:
atmospheric vacuum breaker for commercial and residential
use.
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Four critical
parts of this rule are:
1. Air gaps or
mechanical devices are required whenever an actual or potential
health hazard exist.
2. Annual inspections
and testing by certified testers are required. (Documentation
of proof of inspection must be provided to the Water District
annually.)
3. The Water District
is responsible for ensuring these requirements are met to
protect the public health of our customers.
4. The water customer
has a responsibility to protect the safety of the water system
- both on their premises and in the public system.
Commonly
Used Definitions In The Water Industry
AWWA - American
Water Works Association.
Backflow
- The undesirable reversal of flow in a potable drinking
water distribution system as a result of cross-connection.
Back Pressure Backflow - results when the water flow
is reversed because the undesirable water is at a greater
pressure above atmospheric pressure than the potable water
supply. When the pressure of undesirable water exceeds
the pressure of the potable water supply, back pressure backflow
will occur through unprotected cross-connections.
Back Siphonage - results when the water flow is reversed
because potable water supply is under a vacuum or at a reduced
pressure.
Consumer
- any person, firm, or corporation using or receiving water
from the public water supply system.
Contamination
- The presence of foreign substance (organic, inorganic,
radiological or biological) in water which tends to degrade
its quality so as to constitute a health hazard or impair
the usefulness of water.
Cross-Connection
- A physical connection between a pubic water system and either
another supply of unknown or questionable water quality, any
source which might contain contaminating or polluting substances,
or any source of water treated to a lesser degree in the treatment
process than provided by the Water District.
Health Hazard
- Any conditions, devices or practices in the water supply
system and/or its operation which create or may create, a
danger to the public health and well being of the water consumer.
An example of a health hazard is a cross-connection or potential
cross-connection involving any substance that could, if introduced
into the water supply, cause death, illness, spread disease
or have a high probability of causing such effects.
High Health
Hazard - A cross-connection or potential cross-connection,
or other situation involving any substance that could cause
death, illness, spread of disease or has a high probability
of causing such effects if introduced into the potable drinking
water supply.
Pollution
- The presence of any foreign substance in water that tends
to degrade its quality so as to constitute a health hazard
or impair the usefulness of water.
Potable
- Water that is safe for human consumption as defined by the
Texas Commission on Environmental Quality.
TCEQ -
Texas Commission on Environmental Quality.
USEPA -
United States Environmental Protection Agency
Additional Sources of Information
Foundation
for Cross-Connection Control and Hydraulic Research University
of Southern California - www.usc.edu/dept/fccchr
United States
Environmental Protection Agency - www.epa.gov
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