Cross-Connection

El Paso Water's cross-connection control program

By taking steps to control cross-connections and prevent the possibility of backflow, you will help to protect the public water supply.

A backflow is the unwanted flow from a domestic, industrial or commercial piping system into the potable water distribution system.

To prevent backflow at the point of cross-connection, customers must install a backflow prevention assembly. EPWater allows the installation of one of five types of devices, depending on the assessed hazard and type of installation:

Air gap
Reduced pressure principle assembly
Reduced pressure principle detector assembly
Double check assembly
Pressure vacuum breaker

The installation of a BPA device must be performed by a licensed plumber.

The Texas Commission on Environmental Quality has established regulations to contain hazards of non-return devices at the service connection. TCEQ’s website contains a cross-connection resource page with valuable information.

Backflow prevention assembly inspection, testing

EPWater inspects all BPAs when they are installed. Once installed, all BPAs must be tested annually by a TCEQ licensed tester, and an original copy of that report must be provided to EPWater.

All containment backflow prevention assemblies within the jurisdiction of EPWater must be tested for proper operation by private sector certified backflow prevention technicians at the time of installation, repair or relocation and at least on an annual schedule.

In addition, containment backflow prevention assemblies installed on new services must be tested by certified backflow prevention technicians for proper operation immediately upon installation and before water service is turned on at the premises.

Winterization of backflow preventers

It rarely freezes in El Paso, but when it does, homes and businesses can be caught off guard. If you have an above-ground back flow device and have not yet had your sprinkler system winterized, your system is at risk for freeze damage and water loss.

Turn your sprinkler controller to the OFF position if you have not already done so.
Locate your above ground backflow device. It may be hidden among plants or behind shrubs.
Make sure pipes are insulated or covered. Wrap with insulation tape or newspaper. Cover with a heavy duty trash bag. Watch EPWater’s Protect your Pipes video for tips.
Turn off the isolation valve and open the bleeders with a small flat-head screwdriver. Watch this helpful how-to video.

If your backflow does freeze or break, turn water off at meter. Repairs are the responsibility of the customer and a licensed plumber may be needed.

Cross-connection control regulations and manual

EPWater’s cross-connection control requirements may be found in our Rules and Regulations, Section V – Protection of Water Supply.

Cross-Connection Manual

Approval of backflow prevention assembly

All backflow prevention assemblies that are installed for containment cross-connection control must be approved by the University of Southern California Foundation for Cross-Connection Control and Hydraulic Research. The manual that came with a backflow prevention assembly should indicate that it has been tested and approved by this foundation.

Contact information

For any questions concerning approval of a specific backflow prevention assembly or on testing requirements, please contact 915-594-5440.

Cross-connection FAQ

What is a cross-connection?

A cross-connection is a point in the public water supply or in the customer’s water system that is connected directly, or has the potential of being connected, to a source of non-potable substance through which contaminants or pollutants may enter the public water supply or the customer’s water system.

What is a non-return device?

Non-return devices include installed devices in which the water service connection and the premises' domestic water heater may create a closed domestic water system. Examples include backflow prevention assemblies, check valves, dual check valves, pressure reducing or regulating valves, and in some instances water softeners.

What causes water to flow backward?

Back-siphonage and back pressure is the cause.

What is back-siphonage?

Back-siphonage is the reverse flow of water caused by the supply pressure being less than the pressure in a private plumbing system.

What causes back-pressure?

Heating systems, elevated tanks and pressure-producing systems can create pressure in the customer’s plumbing that exceeds the supply pressure.

What is a backflow prevention assembly (BPA)?

A backflow prevention assembly (BPA) is a testable, mechanical device that uses valves to prevent contaminated water from flowing backwards. The assembly should be installed on the customer's plumbing as close to the meter as possible.

Is it necessary for every customer to install a BPA?

No. Regulations exempt single-family homes used solely for residential purposes from assembly requirements. All other facilities need to be inspected to determine the type of water use and whether a BPA is required.

My building has internal BPAs. Do I still need them at the service connection?

Who installs a backflow prevention assembly?

The customer works directly with the utility to get the process started. Backflow assemblies are installed by licensed plumbers according to the EPWater installation requirements. The final installation must be inspected by EPWater.

Why is annual testing required? Who performs the annual test?

Like any mechanical device, the backflow prevention assembly is subject to failure. Annual testing ensures that the devices are operating as designed. The State of Texas certifies professional BPA testers.