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Cross-Connection Control: Protect Your Drinking Water 

Proteja su agua potable


As Milwaukee’s water utility, we are responsible for making sure the water delivered to your home is safe to drink and use. Please help us keep water safe in your home and our water system safe from potential contamination due to cross-connections.

We’re providing this information as part of our residential property survey required by the City of Milwaukee and the Department of Natural Resources, in collaboration with the City of Milwaukee Department of Neighborhood Services.

Do not leave a hose with the open end in a container, like a bucket of water for car washing.A cross-connection is any actual or potential physical connection between a drinking water system and a source or system of non-drinkable water or substances.

A backflow occurs when water or other substances flow in the opposite direction than intended, allowing contaminants to enter the public water system or consumer’s plumbing.

A hose bibb is the part of a faucet with screw threads on the exterior for attaching a hose.

Examples of cross connections that may allow contaminated water to mix with clean drinking water:

  • A hose connected to the laundry tub faucet is submerged in a sink filled with soapy water.
  • A toilet fill valve (ballcock) is submerged below the water overflow line.
  • A non-plumbing-approved fill valve was installed in a toilet.
  • A handheld shower hose that does not have a back flow preventer.

Backflow can be the result of a pressure drop in the drinking water system due to:

  • a water main break.
  • a hydrant opened for testing.
  • firefighters openomg a hydrant for water for firefighting.
  • a power outage to a pump.

Garden hoses connected to outside faucets can create a potential cross-connection. Here are tips to avoid problems:

  • Install a hose bibb vacuum breaker on your exterior faucet, or hose bibb, before attaching a garden hose.
  • Do not leave a hose with the open end in a container, like a bucket of water for car washing.
  • Do not leave a hose submerged in a swimming pool.
  • After using a sprayer attached to a hose for weed killing, etc., remove the sprayer for storage.
  • Do not leave a hose lying on the ground or lawn, which may be contaminated with fertilizer and garden chemicals. Hang up the hose on a rack.

This exterior faucet, or hose bibb, has a hose bibb vacuum breaker attached to it to prevent backflow. Make sure to drain exterior hose bibb vacuum breakers before freezing winter temperatures set in.Take action. Put a backflow prevention device, or hose bibb vacuum breaker:

  • On the laundry tub faucet.
  • On the exterior faucet where you connect a garden hose.

Customer Service Center

Zeidler Municipal Building
841 N. Broadway, Room 406
Milwaukee, WI 53202
Monday - Friday 7:30 a.m. - 5:00 p.m.

Telephone  (414) 286-2830
24-Hour Control Center    (414) 286-3710
TDD   (414) 286-8801
Fax   (414) 286-5452
Email (non-emergency)  
News Media - Sandy Rusch Walton
  (414) 286-3261
U.S. Mail   P.O. Box 3268
 Milwaukee, WI 53201-3268