Backflow or Cross-Connection

What is a cross connection? A cross connection is an arrangement of piping which could allow undesirable water, lawn fertilizer, bacteria, chemicals, etc. to enter the drinking (potable) water as a result of backflow due to backsiphonage or backpressure. Most of the time this is a nuisance. However there are many stories and examples of sickness and death occurring with backflow situations.

Backsiphonage is the reversal of flow in a piping system caused by a negative pressure. Some examples of backsiphonage are during watermain breaks, fire fighting events or during a interruption of a building’s water supply.

Backpressure is the reversal of flow in a system due to an increase in the downstream pressure above that of the supply pressure. Backpressure could be caused by a high pressure boiler or a booster pump.

How can I eliminate cross connections? Cross connections can be eliminated by making sure each point of use is protected against backflow. This can be accomplished by maintaining air gaps or installing required backflow preventers. This will assure no undesirable water is not able to enter the potable water supply piping.

Call Ferrer Plumbing to go over possible cross-connections issues. Receive a detailed report of how we can correct these problems, and keep your water safe.

Examples of cross-connection

  1. Sinks- Faucets on the sinks need to maintain an air gap of at least twice the diameter of the supply pipe above the flood level rim of the tub or sink.
  2. Hose bibbs or spigots- By installing a hose connection vacuum breaker that is approved for out-door use on the hose bibb or install a spigot with a integrated vacuum beaker.
  3. Water operated backup sump pumps- Most water operated backup sump pumps are required to have a reduced pressure principle backflow preventer that is installed on the water supply to the pump.
  4. Toilets- Install an anti-siphon fill valve in the toilet tank. Following the manufactures installation instructions to make sure the critical level mark is at least 1” above the overflow tube.
  5. Boilers- Low pressure non-treated boilers must be protected against backflow by a double check valve with an intermediate atmospheric. Chemically treated boilers are required to be protected against backflow with a reduced pressure principle backflow preventer.
  6. Lawn irrigation system– Lawn irrigation systems are required to be protected against backflow. Most systems are protected by a pressure vacuum breaker. If the design is different it may need a reduced pressure principle backflow preventer.

Backflow Preventer Testing

Pressure vacuum breakers, reduced pressure principle assembly, double check, and spill resistant vacuum breakers are all testable assemblies. These assemblies are required to be periodically tested upon notification by the water system purveyor. The test must be completed by an ASSE certified backflow tester. Thankfully Ferrer plumbing is certified to test these assemblies and complete the proper paperwork for the water department.

Homeowners that get their drinking water from a public water system are required by the “Michigan Safe Drinking Water Act” to maintain their plumbing systems in a manner free of cross connection. Read more here. 

If you have one of these on the side of your home, you will need Ferrer Plumbing to test this device to verify the device is working effectively and safely.