Residential Cross-Connection Information

Your water can be contaminated if connections to your plumbing system are not properly protected! The purpose of the local Cross-Connection Control Program, as required by State Plumbing Code and Regulations, is to ensure that everyone in the community has safe, clean drinking water.

Contamination may occur when you turn on your faucet, you expect the water to be as safe as when it left the treatment plant. However, certain hydraulic conditions left unprotected within your plumbing system may allow hazardous substances to contaminate your drinking water or even the public water supply. 

Water normally flows in one direction. However, under certain conditions, water can flow backward; this is known as backflow. Two situations can cause water to flow backward: back siphonage and back pressure.

Common Terms


  • Cross-Connection: This is an actual or potential connection between the safe drinking water (potable) supply and a source of contamination or pollution. State plumbing codes require approved backflow prevention methods installed at every point of potable water connection and use. Cross-Connections must be properly protected or eliminated.
  • Backsiphonage: May occur due to a loss of pressure in the municipal water system during a fire fighting emergency, a water main break or system repair. This creates a siphon in your plumbing system which can draw water out of a sink or bucket and back into your water or the public water system. 
  • Backpressure: May be created when a source of pressure (such as a boiler) creates a pressure greater than the pressure supplied from the public water system. This may cause contaminated water to be pushed into your plumbing system through an unprotected cross-connection.

Do...

  • Keep the ends of the hoses clear of all possible contaminants. 
  • Make sure dishwashers are installed with a proper "air gap" device. 
  • Verify and install a simple hose bibb vacuum breaker on all threaded faucets around your home.
  • Make sure water treatment devices such as water softners have the proper "air gap", which is a minimum of one inch above any drain.

Don't...

  • Submerge hoses in buckets, pools, tubs, sinks, or ponds.
  • Use spray attachments without a backflow prevention device. 
  • Connect waste pipes from water softeners or other treatment systems directly to the sewer or submerged drain pipe. Always be sure there is a one-inch "air gap" separation.
bathroom
kitchen

Public Safety


To avoid contamination, backflow preventers are required by state plumbing codes wherever there is an actual or potential hazard for a cross-connection. The Wisconsin Department of Natural Resources (DNR) requires all public water suppliers to maintain an ongoing Cross-Connection Control Program involving public education, onsite inspections, and possible corrective actions by building owners if required.

More Information