To protect public health, our Cross-Connection Control (CCC) and
Backflow Prevention Program is committed to helping you protect
your drinking water system from potential contamination. The Cross-Connection Control Subcommittee
advises us in this effort.
How Cross Connection and
Backflow Can Lead to Contaminated Water
It really happened in Texas:
- While mixing a batch of pesticide, a worker pushed a garden
hose into the tank until it touched the bottom.
- Nearby, city utility workers opened a flush valve, releasing a
large flow of water from a water main.
- Where the worker was mixing the pesticide, the water pressure
dropped, and the flow in the hose reversed. Water and pesticides
flowed from the pesticide tank back through the hose and into the
water lines.
Luckily, this is where it stopped: The worker mixing the
pesticide realized the danger and alerted the utility workers, who
closed the flush valve before the contamination reached the
city’s distribution line. Still, good water and time were
wasted:
- To remove the pesticide from the water lines of the customer,
utility workers flushed those lines.
- In case the water main had been contaminated, the utility
workers had to flush the city’s distribution line, too.
- Until testing showed authorities that the city’s water
was safe, they warned customers in the area not to drink it.
As shown by the case
histories of backflow incidents 
maintained by the backflow-prevention education program of the
University of Florida’s TREEO Center, not all cases of cross
connection and backflow end so smoothly.
Definitions
- cross connection
- a physical connection between drinkable water and a liquid or
gas that could make the water unsafe to drink (wherever there is a
cross connection, there is a potential threat to public health from
the liquid or gas contaminants)
- backflow
- water flowing in the opposite of its intended direction, either
from a loss of pressure in the supply lines or an increase in
pressure on the customer’s side (in either of these
situations, if any affected customer’s pipes include a cross
connection, contaminants could be drawn through the cross
connection into that customer’s pipes—and, if the
backflow continues, perhaps even into the water mains)
Your Role as a Water
Customer
By taking steps to control cross connections and prevent the
possibility of backflow at your home, you will help to protect the
public water supply and ensure that your family continues to enjoy
safe drinking water. Garden hoses and irrigation systems are common
concerns, but there are other common residential sources of cross
connections, too.
Garden Hoses and Backflow
The garden hose is the most common cross connection. Each of
these common uses of a garden hose sets up a cross connection:
- forcing it into a clogged gutter, downspout, or sewer pipe to
flush out the clog
- connecting it directly to a hose-end sprayer to apply pesticide
or fertilizer to your yard
- connecting it to a soap-and-brush attachment to wash your car,
boat, or siding
- letting the end of the hose lie in a puddle or pool of water on
the ground
No doubt you can think of other examples. In each of these
cases, if backflow happens, your household’s water lines
could be contaminated. Depending on how long the backflow event
lasts, the contamination could spread to the public drinking water
system. Fortunately, there are two inexpensive ways to solve this
problem:
- Make sure that the end of your garden hose is never become
submerged in or connected to a nonpotable substance. This solution
is free, but not highly reliable. Can you always be this
careful?
- Install a hose bibb vacuum breaker on each of
your outside faucets. These inexpensive devices are designed to
allow water to flow in only one direction. You can find them at
most home supply stores and through plumbing suppliers. Before you
use a hose-end sprayer, you should first install a hose bibb vacuum
breaker at the faucet.
Irrigation Systems and Backflow
As a homeowner, you may install and maintain your own irrigation
system, but it’s still important to have a suitable backflow
prevention assembly (BPA) in place and to be sure that it works
properly. Here are a few ways you can do just that:
- Hire a licensed irrigator. You can find one from our online licensing
database
.
- If you install your own system, have a licensed BPA tester
confirm that the BPA is installed and operating properly. Licensed
BPA testers are also listed in our online licensing
database
.
- However your irrigation system is installed, have a licensed
BPA tester check it periodically to make sure the BPA is working.
Although no rule requires follow-up testing of residential
irrigation systems, periodic testing is a good idea because they
are mechanical systems and can fail over time.
Your Water System’s
Role
Your water system’s role begins with good system
maintenance and sound operations. By replacing pipes before they
break, taking steps to ensure that system pressures do not fall
during periods of high demand, and asking for the cooperation of
customers when there is a risk that system pressures could fall
below safe levels, your public water system operator reduces the
risk of backflow.
Many public water systems also operate rigorous cross-connection
control programs of their own. They identify locations where the
risk of cross connection is high and ensure that the proper
measures are taken to minimize that risk. For example, these and
other businesses would be required to install high-grade backflow
prevention assemblies and have them tested by a certified tester
annually:
- mortuaries
- minor surgery centers
- hospitals
- chemical plants
Another aspect of an effective CCC program is the customer
sevice inspection. Your public water system may hire (on contract
or on staff) one or more licensed customer service inspectors
(CSIs) to ensure that no cross connections are present in these
ways:
- Inspect all new construction.
- Inspect existing service that has undergone substantial
modification.
- Inspect existing service whenever there is a reason to suspect
that a hazard or a source of contamination may be present.
Our Compliance Support Division licenses CSIs and maintains a database of licensed
CSIs
.
To learn more, read Introduction to
Cross-Connection Control or
the technical guidance.
The TCEQ’s Role in
Cross-Connection Control and Backflow Prevention
We require water providers to meet standards to obtain, treat,
and deliver water. A public water system’s Cross-Connection
Control Program is inspected during routine investigations made by
our regional staff. Technical assistance in the area of
cross-connection control is offered to public water systems by
staff from our central office.
We also coordinate meetings of the Cross-Connection Control (CCC)
Subcommittee, a group of participants that meet to discuss
issues related to cross-connection control and backflow prevention.
A voluntary group that is open to anyone who would like to join,
the CCC Subcommittee provides us with expanded knowledge and
resources to address cross-connection control and backflow
prevention throughout Texas.
Technical Guidance
Individual copies of these publications are free:
These manuals are available for purchase from their
publishers:
The American Backflow Prevention Association (ABPA) has an online forum for discussing backflow
incidents and
their prevention.
Staff
Contact
For more information, call our main Water Supply Division line,
512-239-4691, and ask for the Cross-Connection Control and Backflow
Prevention Program coordinator. You may also e-mail your question
or comment to pdws@tceq.state.tx.us.
Please include “Cross-Connection/Backflow Prevention”
in the subject line of your e-mail.
