Backflow Prevention
As a Roats Water System customer, you expect your drinking water to be safe. We are committed to providing you the healthiest, highest quality water, but we need your help. A cross connection is any connection between pipes that carry drinking water and the pipes or fixtures that carry other types of water or substances that are not safe to drink.
Lawn irrigation systems, swimming pools and hot tubs are common cross connection points. When the sprinklers on irrigation systems are nested underground, it is possible for contaminated water to flow into the sprinklers. In swimming pools and hot tubs, if the water inlet (point where water flows into the pool or tub) is submerged, it is a cross connection. This often occurs in hot tubs with submerged inlets that are made of permanent hard piping.
Drinking water normally flows in one direction, although under certain circumstances it can flow in the opposite direction, or "backflow". Backflow is caused either by "backsiphonage" or "backpressure".
Backsiphonage
Backsiphonage is caused by reduced pressure in the supply line to a facility or plumbing fixture. Backsiphonage may be caused by an open fire hydrant, water main breaks and water system maintenance.
Backpressure
Backpressure occurs when a drinking water system is connected to another system operating at a higher pressure. Backpressure may be caused by auxiliary water pumps, boilers, and/or elevated buildings.
When backflow occurs, water runs backwards through your pipes and into the drinking water system. When this happens, the water flowing backwards could contain something that could contaminate the drinking water supply. Roats Water System strives to maintain positive pressure in the system at all times, but events such as main breaks and fire fighting can contribute to backflow conditions. The cross connection program seeks to eliminate or protect all cross connections in the public water system and help customers comply with backflow prevention practices and regulations.
Prevention
Fortunately, there are many things you can do to help prevent contamination of the public water system due to backflow. The primary tool in protection of the public water supply is the installation and regular testing of a backflow prevention assembly at the water meter. Additionally, there are several ways to protect your home from contamination due to backflow.
Swimming pools and hot tubs: Ensure that if a water hose is used to fill these units, it is protected with a hose bib vacuum breaker installed on the faucet.
Residential boilers: Ensure an approved backflow assembly is installed, is in good working condition, and is tested annually.
Private wells: Ensure that well systems are not connected to a public water system. If it is connected, it must have a backflow assembly at the meter, be in good working condition, and tested annually.
Residential Irrigation Systems: All irrigation systems, new or existing, must be equipped with an approved backflow prevention assembly. Only properly installed, state-approved backflow prevention assemblies meet the plumbing code and provide adequate health protection for your family and neighbors.
Backflow Case History
BACKFLOW AT A PREMISES WHERE THE CONSUMER'S POTABLE WATER SYSTEM SUPPLIES AN IRRIGATION PIPING SYSTEM
DATE OF BACKFLOW INCIDENT: October 1991
LOCATION OF BACKFLOW INCIDENT: Southgate, Michigan SOURCE(S) OF INFORMATION:
- Drinking Water & Backflow Prevention, Volume 9 Number 6 (June 1992)
- Pacific Northwest Section of the American Water Works Association, Summary of Backflow Incidents, Fourth Edition, 1995
- Watts Industries, Inc.; Watts Regulator News/Stop Backflow
CASE HISTORY
On October 1, 1991, two homeowners in the City of Southgate, Michigan, found parasitic worms, or nematodes, in their water. One homeowner found the worms swimming around in his bathtub when he started filling the tub for his child. He also found rust and other debris in his water. The Wayne County Health Department determined that water had backflowed through a residential irrigation system into the public water system.
An atmospheric vacuum breaker on the residential irrigation system had malfunctioned because the device's air inlet valve had stuck to the device's air inlet port. There was a water main break, which caused a vacuum in the public water system. The vacuum in the public water system sucked some water--and some nematodes--from the irrigation system into the public water system.
Crews from the City's Department of Public Services opened fire hydrants and flushed all the water mains located three blocks north and south of where the backflow incident occurred. Analysis of subsequent water samples collected by the Department of Public Services showed no detectable coliform bacteria.
The County cited the owner of the irrigation system for improper installation of the system. The contractor that this resident employed to install the irrigation system did not have a City permit and used a "cheap" atmospheric vacuum breaker.
To read more case studies, click on this link.
The Legalities
The Oregon Administrative Rules Chapter 333-61-070 regulates that a water purveyor shall carry out a cross connection control inspection program, discontinuing water service to premises which fail to install an approved backflow assembly where a cross connection or potential cross connection may exist, and ensure the required backflow assembly is tested on an annual basis.
Questions
If you are unsure if your backflow prevention assembly installation or testing requirements, please contact our office to schedule a free appointment with our Cross Connection Control Specialist, (541) 382-3029.
Additional Information
State of Oregon: http://www.oregon.gov/DHS/ph/crossconnection/
American Backflow Prevention Association: http://abpa.org/Schedule