A cross connection is a connection between the drinking water line and some other liquid, gas or chemical.
Cross connections, if not properly protected or eliminated, can cause health problems and spread disease.
There are two methods by which contamination can enter the drinking water, backpressure and backsiphonage. Backpressure occurs when the pressure in the home exceeds the drinking water pressure. This can be caused by air conditioning units, boiler systems and other pressure building devices connected to the drinking water. Backsiphonage occurs when the drinking water pressure drops off and a vacuum sucks the water from the buildings. This can be caused routinely by a fire department’s use of water due to a fire, water main breaks, and other heavy water demand.
Garden hoses are the most common household cross connection. Hoses placed into swimming pools or attached to weed-killing or garden chemical sprayers are possible sources of contamination. Other common cross connections are irrigation systems, boilers, and water supplied appliances. Home businesses such as beauty parlors are locations where cross connections can be found.
The Acton Water District requires all businesses to have a cross connection device called a reduced-pressure principle backflow preventer located immediately downstream of the meter. All other cross connections within the building must also be protected with backflow devices.
There has never been a cross connection incident in Acton to our knowledge, but there have been several in the state of Massachusetts and even more in the country. One particular incident occurred at a college when a water fountain was hooked up to an unapproved water line and the entire football team was infected with hepatitis A.
Everyone should be aware and do their part to prevent drinking from becoming contaminated by a cross connection. By surveying all industrial, commercial and institutional facilities for cross connections the Water District ensures that the water supplied to the last free flowing tap in every home and office is of the highest quality All residential homes with irrigation systems are recorded and required to have backflow protection. Routine yearly testing on all devices is done to ensure maximum protection.