WHAT IS A CROSS CONNECTION?
Cross Connection means any actual or potential connection between a drinking (potable) water system and any other source or system through which it is possible to introduce into the public drinking water system any used water, industrial fluid, gas or substance other than the intended potable water. For example, if you have a pump moving non-potable water and hook into the drinking water system to supply water for the pump seal, a cross connection or mixing may lead to contamination of the drinking water. Also see backsiphonage, backpressure and backflow.
Some other useful definitions when talking about cross connection are:
Air gap - The unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, catch basin, plumbing fixture or other device and the flood level rim of the receptacle. This distance shall be two times the diameter of the effective opening for openings greater than one inch in diameter where walls or obstructions are spaced from the nearest inside edge of the pipe opening a distance greater than three times the diameter of the effective openings for a single wall, or a distance greater than four times the diameter of the effective opening for two intersecting walls. This distance shall be three times the diameter of the effective opening where walls or obstructions are closer than the distances indicated above.
Backflow - The undesirable reversal of flow of water or mixtures of water and other liquids, gases, or other substances into the distribution pipes of the potable water supply from any source. Also see backsiphonage, backpressure and cross connection.
Backpressure - The phenomena that occurs when the customer's pressure is higher than the supply pressure, This could be caused by an unprotected cross connection between a drinking water supply and a pressurized irrigation system, a boiler, a pressurized industrial process, elevation differences, air or steam pressure, use of booster pumps or any other source of pressure. Also see backflow, backsiphonage and cross connection.
Backsiphonage - A form of backflow due to a reduction in system pressure which causes a subatmospheric or negative pressure to exist at a site or point in the water system. Also see backflow and cross connection.
RECOGNIZING CROSS CONNECTIONS
All homes have potential cross connections so it is important for you to be able to recognize those that may exist in your home. if your water is discolored or has an unusual odor or taste, submit a Service Request under “Water Miscellaneous”.
Common household cross connections include:
When submerged, for instance in a bucket of soapy water or cleaning solvent, a loss in water pressure would cause the contaminated liquid to be sucked through the hose and into your drinking water. Hoses also act as a cross connection when attached to things such as weed sprayers. Imagine all the chemicals in your weed sprayer flowing back through your hose and into your water.
It is important to know that anything attached to the end of the hose has the potential to backflow. Hose bibbs can be protected by built in or easily installed vacuum breakers, (which are available at your local hardware store). A frost proof hose bibb vacuum breaker is recommended for colder climates.
In-ground Lawn Irrigation Systems
A study conducted by the American Backflow Prevention Association found that the most common cross connections come from irrigation systems. With a lawn irrigation system, water can accumulate by the sprinkler heads. A loss in water pressure would then cause the water to be sucked back through the pipes and into your plumbing system, carrying with it any fertilizer chemicals, pesticides, animal waste, or other bacteria and parasites on the ground. All lawn irrigation systems should be protected by a reduced pressure (RP) backflow assembly, which must be tested annually. Please consult your sprinkler contractor or plumber to make sure your system is protected and up to current code.
Additional cross connections that can be found in the home include:
- Residential fire protection systems
- Swimming pools/hot tubs
- Private wells
- Any in-home business using chemicals or medical supplies/equipment (for example, In-home businesses such as photographers, hairdressers, or taxidermists)
PREVENTION AND WHAT TO DO
Cross Connections can occur every day but often go unreported. They can cause health problems ranging from gastrointestinal illnesses (often attributed to food poisoning) to much more serious health issues. Cross Connections can also negatively affect the overall quality of your water. As the water customer, you are the best resource in preventing backflow and cross connections.
There are multiple ways you can prevent a backflow incident from occurring, including:
- Have an “Air Gap”, which is at least two times the diameter of the pipe away from the top of the container you are filling. For example, if you are filling a kiddie pool or watering trough with a 1-inch garden hose, keep the end of the garden hose at least 2 inches above the rim of the container.
- Another proven method for most applications it to have an “RP” or reduced pressure principle backflow assembly, which protects against backpressure and backsiphonage.
- If you have concerns regarding your property’s connections, submit a Service Request under “Water Miscellaneous” detailing the conditions you are observing, and someone from the Spanish Fork Water Division will contact you.