Backflow Prevention FAQ

Q. What is a cross-connection?
According to the Texas Commission on Environmental Quality, a cross-connection is “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).” Examples of some common cross-connections are carwashes, mortuaries, chemical plants, fire sprinkler systems, lawn irrigation systems, dry cleaners, medical facilities, veterinarian clinics, dental offices, and carbonated fountain drink machines.

Q. What is backflow?
Backflow is 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.

Q. How does backflow occur?
Backflow may occur simply because the water distribution system lost pressure. Backflow, reversal of flow from its normal direction, is usually caused by a back-pressure or backsiphonage. Back-pressure when the water pressure within a customer’s plumbing system exceeds the pressure of the water distribution system supplying the water. This backpressure might be caused by a difference in elevation, by a pump in a steam boiler, or by other means. Backsiphonage may occur when the water pressure within the distribution system falls below that of the plumbing system it is supplying. This might happen due to a fire department truck pumping water out of the distribution system faster than the water treatment plant equipment can replace it. The water rushing downhill due to a broken water main might create a partial vacuum on some plumbing systems connected in the vicinity of the break. Perhaps, simply flushing the water pipes to clean them may cause this phenomenon. Examples of backflow incidents

Q. I have lived in my home with an active sprinkler system for years, why do I have to do this all of the sudden?
Our department was recently inspected by our state regulatory authority and they determined that we were deficient in our recordkeeping and compliance for backflow prevention testing. This is a city ordinance as well as a state and federal regulation. We are now doing everything possible to make sure that everyone is compliant and that our water quality is clean and protected.

Q. Why do I have to have my backflow prevention assembly tested annually?
Backflow prevention assemblies have internal seals, springs, and moving parts that wear out. Regular testing is required to ensure backflow prevention assemblies are functioning properly and have not been bypassed. A visual check of air gap assemblies is sufficient, while mechanical assemblies must be tested with special equipment.

Q. How often must a backflow prevention assembly be tested? 
In order to insure the proper operation of a backflow prevention assembly, it must be tested and certified upon installation and at least once a year thereafter by a licensed backflow tester.

Q. I have a lawn irrigation system that was installed before backflow prevention devices were mandatory. Do I have to have a device installed or am I “grand-fathered in”?
Any hazard must be isolated from the drinking-water supply regardless of when the hazard was first created or the site constructed. Many customers believe that, if their residence or facility was constructed before the TCEQ’s adoption of regulations for cross-connection control and the City of Longview’s ordinance, then they are not subject (i.e., they are “grandfathered”) to the regulations. That is not true. There are no “grandfather” clauses that apply to cross-connection control.

Q. I received a letter about having my backflow prevention assembly tested, what do I do now?
Since the backflow prevention assembly is a fixture of your private plumbing system, you as the property owner are responsible for the annual testing and/or repairs of the backflow prevention device. You will need to hire a licensed tester and give the tester your Customer Confirmation Number from the letter so the tester can submit the test results. 

Q. I received a letter to have my backflow prevention device tested but I am a renter. What do I do now?
The letters are addressed of whoever receives the water bill. If you are a renter and you are not responsible for the maintenance plumbing of that property then you will need to forward the letter to your landlord. 

Q. I received a letter to have my backflow prevention device for my lawn sprinkler tested but I do not use my sprinkler system during anytime of the year. Do I still have to have it tested?
If you do not use your sprinkler system at any time throughout of the year, you can sign and submit an Inactive Irrigation System Certificate (link) to be filed in place of a yearly backflow test. The certificate can be 

Mailed to:
City of Longview
Attn: Backflow Prevention
P.O. Box 1952
Longview, TX 75606-1952

Faxed to:

Hand Delivered to:
Water Utilities Department
300 W. Cotton St.
Longview, TX 75602

The valves to the inactive sprinkler system must be turned off on both sides of the backflow prevention device. The city will routinely monitor water usage to determine if customers who have filed the Inactive Irrigation System Certificate are using their sprinkler systems. Using the system will void the certificate and the customer will be required to have a backflow test performed immediately or risk disruption of water service.

Q. How can I find a certified backflow prevention tester?
The City of Longview cannot recommend testers but can provide a list of testers that have registered with the city and have previously submitted test reports for Longview water customers. An updated list is available here. 

Q. How do I change the contact information for a backflow prevention assembly on my property?
To change the contact name, address or telephone number for a backflow prevention assembly, the customer may contact the Cross-Connection Control/ Backflow Prevention Program at 903-237-2787.

Q. What if my backflow prevention assembly fails the test?
If an assembly fails the test, the property owner must have it repaired or replaced and retested by a certified tester. If the assembly cannot be repaired and a replacement is necessary, a permit from Developmental Services is required.

Q. What happens if I don’t have my assembly tested?
If a water customer decides not to have their “in use” backflow prevention assembly tested, water services could be shut off to the property until the device has been tested and submitted to BSI Online. According to the City of Longview’s ordinance, the property owner could also be fined up to $2,000 for noncompliance.  

Q. I have several backflow prevention assemblies with different due dates: How do I get them tested at the same time?
Contact the staff of the City of Longview’s Cross-connection Control/Backflow Prevention Program at 903-237-2787 and the staff will help with coordinating the due dates of the tests.  

Q. I am a licensed tester but I am not registered as a tester with the City of Longview. What do I do to become registered?
BSI Online tracks registered testing companies, testers, tester licenses, and test kit calibration certificates. You will need to go to their website at and follow the steps given below by BSI Online: 

“Your first step to begin submitting backflow test reports is to complete the fast and easy signup process. To begin, simply click the "Signup" button below, and fill in some basic information for your company. You will use your new user name and password to login into BSI Online. We will also need you to send in copies of all applicable licenses and test kit calibration certificates prior to filing reports.”