Cross-Connection

Backflow Prevention Policy

What is a cross-connection? According to TCEQ 290.38(12), a cross-connection is a physical or potential connection between a public water supply and:

  1. Another supply of unknown or questionable quality.
  2. A source which may contain polluting or contaminating substances.
  3. Any water source treated to a lesser degree.

Walnut Creek SUD is updating our policy for cross-connection and backflow prevention. The customer will have 45 days to comply with our policy once a cross-connection or potential cross-connection has been identified. After which time IF the customer fails to come into compliance with the policy, WATER SERVICE will be terminated until customer is in compliance with the cross-connection and backflow prevention policy.

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.

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 the TCEQ online licensing database.
  • If you install your own system, you must have a licensed BPA tester confirm that the BPA is installed and operating properly. Licensed BPA testers are also listed in the TCEQ online licensing database.
  • Irrigation Systems can only be connected to one water source (Public Water Supply, Lake, or Well). If more than one source is available to you the system cannot be connected to both. If it is determined that the system has more than one source of water that is in violation.
  • All irrigation systems connected to Public Water Supply are required to have a Double Check Valve (DCV) and be tested upon installation and annually by a licensed BPA tester. However if you do not have this device tested it is in violation.

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
  • using your hose to fill your pool by submerging it

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 submerged in or connected to a non-potable substance. This solution is free, but not highly reliable. Can you always be this careful?
  • Install ahose bib vacuum breaker (HBVB)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 bib vacuum breaker at the faucet.

Inside Plumbing

  • Toilets must have anti-siphon ballcocks installed and functioning properly.

Wells

  • If a WELL is present on the customers property it has to have a physical separation from the public water supply (valves are not an effective method). This separation must be a minimum of 18 inches and be capped to insure that a connection between the two systems cannot be made i.e. the customer cannot switch between their well and the public water supply.
  • You can use the well for irrigation purposes.

RV Parks

When owners of RVs flush and clean the waste from the plumbing system of RVs, a potential threat to the potable water supply may be created. Many RVs are sold today with a “sewer flusher” connection which allows the black water tank to be flushed. While most of the devices come with some form of backflow protection, TCEQ Rule 290.47(i) prohibits the connection of a public water supply to a sewer pipe. Since the black water tank of an RV holds the same materials as a sewer pipe, devices that allow connection between the public water supply and black water tanks are a threat to the potable water supply of the RV Park and the public water supply.

RV PARKS THAT ALLOW BLACKWATER TANK CLEAN OUT

Backflow Protection:

  • A Spill-resistant Pressure Vacuum Breaker (SVB), or Pressure Vacuum Breaker (PVB) is required at all connections where black water tank clean out is permitted. Which must be installed 12” above highest connection. This device must be tested upon installation and annually.
  • A Reduced Pressure-principle backflow prevention assembly (RPBA) is required at the meter. Which must be installed 12” above grade and enclosed in an approved box to prevent freezing. This device must be tested upon installation and annually.

RV PARKS THAT DO NOT ALLOW BLACKWATER TANK CLEAN OUT

Backflow Protection:

  • A Double Check Valve (DC) is required at the meter. This device must be tested upon installation and annually.
  • All hose bibs are required to have Hose bib Vacuum Breakers (HBVB) installed.

April 4, 2018