| Cross-Connection Control - Preventing Drinking Water Contamination
Cross-Connection References
Tumwater's Cross Connection Control Plan
Tumwater's Ordinance - Cross
Backflow Incident Form
WA Department of Health Regulations
Backflow Assembly Details
Double Check Valve Installation
Pressure Vacuum Breaker Assembly
RP Installation
Striving to Keep Tumwater’s Water Clean
Throughout the U.S., there are many cases of drinking water becoming contaminated as a result of cross-connections. A cross-connection is a connection between the potable drinking water system and a non-potable substance. This interconnection becomes a hazard when backflow conditions caused by a water main break, fire, pump failures, or increased demand, result in pressure losses and contaminants flowing into the city’s drinking water system.
The City of Tumwater is committed to ensuring your drinking water remains clean and safe. The Washington State Department of Health requires proper backflow prevention assemblies on all commercial properties and some residential properties that are connected to the city’s water system.
This page contains information about cross-connection control and a includes a link to a survey regarding plumbing and other fixtures on your property that may be a potential source of backflow contamination.
Please take a few moments to read the information below, and complete the survey. Your assistance will allow us to help keep Tumwater’s drinking water clean and safe.
Examples of Contamination from Cross-connections
In 1993, an Oregon homeowner installed an irrigation system using water pumped from a decorative pond in an area near an old septic drain field. When the pond’s pump failed, the homeowner connected a hose from the home’s drinking water system to the irrigation piping. When the pump was brought back online, it forced pond water through the hose connection, through the home, and into the city’s potable water system.
In 1982, a Michigan resident was spraying his garden with pesticides using a common hose and sprayer attachment. While he was applying the pesticide, the public water system needed to shut down temporarily. The homeowner noticed a drop in pressure and within a few moments, the pesticide disappeared from the container: Backsiphonage had drawn the pesticide into the hose, through the house plumbing, and into the public drinking water system.
 
What is Backflow?
Backflow occurs when the pressure in the drinking water system drops, siphoning water and any substances in it into the public water system. This is called backsiphonage and may occur when there is an unusually high use of water in an area, such as fire fighting or a broken water main. Backsiphonage may also occur when a hose is left in a full mop bucket or watering can containing garden chemicals.
Another type of backflow, called backpressure, occurs when there is a cross-connection with a container or pipe containing non-potable substances under pressure. When the public water system’s pressure drops, the pressurized system actually pumps the material into the public’s system.
 
How is Backflow Prevented?
Federal law requires the City of Tumwater to protect our drinking water system from contamination due to cross-connections. The city regularly surveys all water system connections in the city’s service area to locate potential cross-connections and determine which type of backflow protection, if any, is necessary to protect both the consumer and the water system. You may receive such a visit as part of this program.
The goal of the City of Tumwater’s cross-connection control program is to protect the purity of drinking water we so proudly serve. With your cooperation, the city’s cross-connection control program will help keep our water free from contamination and health hazards.
Do you have a potential Cross-Connection?
Please take a few moments to complete the survey. Your assistance will allow us to help keep Tumwater’s drinking water clean and safe. Once submitted and reviewed, a Tumwater staff person will contact you regarding your site and discuss any potential cross-connections you may have.
For more information, please contact Dennis Winchel at 360-754-4150, or via e-mail.
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