Cross Connection Surveys (6/15/07)

Cross-connections that contaminate drinking water distribution lines are a major concern. A cross-connection is formed at any point where a drinking water line connects to equipment (boilers), systems containing chemicals (air conditioning systems, fire sprinkler systems, irrigation systems), or water sources of questionable quality. Cross-connection contamination can occur when the pressure in the equipment or system is grater than the pressure inside the drinking water line (backpressure). Contamination can also occur when the pressure in the drinking water line drops due to fairly routine occurrences (main breaks, heavy water demand) causing contaminants to be sucked out from the equipment and into the drinking water line (backsiphonage).

Outside water taps and garden hoses tend to be the most common sources of cross-contamination at home. The garden hose creates a hazard when submerged in a swimming pool or when attached to a chemical sprayer for weed killing. Fertilizers, cesspools or garden chemicals may contaminate garden hoses that are left lying on the ground. Improperly installed valves in your toilet could also be a source of cross connection contamination.

Community water supplies are continuously jeopardized by cross-connections unless appropriate valves, known as backflow prevention devices are installed and maintained. This year Kaukauna Utilities started a backflow and cross-connection program. This program is very important for the safety and protection of the public water supply.

Kaukauna Utilities has hired an outside firm (Hydro Designs) to do cross-connection surveys in the small business sector and in larger commercial buildings; this will be done over a three-year period, with 150 buildings being surveyed each year. Starting in early 2008, the Kaukauna Utilities staff will begin doing cross-connection surveys in residential homes. These surveys involve inspecting each homeowner’s plumbing system to make sure there are no potential cross-connections that could possibly contaminate the city water supply. These surveys take an average of 20 minutes per residence. There will be no cost to the homeowner for the survey, but there might be minor charges to fix any possible cross-connection problem that is found. If, for some reason, the city lost water pressure due to a major water main break or the water utility had to shot off the water, any plumbing fixture in a home that didn’t have the proper backflow protection could contaminate the public water supply. Kaukauna Utilities will be notifying homeowners by mail about setting up appointments for these surveys. Thank you in advance for your cooperation.

For more information review the Cross-connection control manual from the U.S. EPA’s Web site at www.epa.gov/safewater/crossconnection.html. You can also call the Safe Drinking Water Hotline at 800-426-4791.