Backflow Prevention

The Greater Augusta Utility District has an active program to identify and prevent cross connections between drinking water and non-drinking water sources throughout the drinking water distribution system.

This program is compliant with Maine regulations that require water systems to ensure their customers are drinking water directly from the main, not water from their neighbor's swimming pool.

Browse this page for more information about what a cross connection is, why you should be worried about it, and what you can do to prevent it from happening.  


Many devices do not need to be tested.  However, other devices that are installed at high hazard locations are tested each year on the following schedule:

  • Annual test results are due by May 31st each year.
  • Semi-annual tests are due May 31st and November 30th.


A cross connection occurs when a drinking water supply pipe connects to a non-drinking water supply source or pipe. An example of this is a connection with a residential home. You may not think of your home as having hazards to a water supply, but if you have a hose that has a submerged end in a kiddie pool or a carwash bucket, then you've created a cross connection. If a watermain broke, the potential exists for a suction event to occur. This means that water in your kiddie pool or carwash bucket could be drawn into the water system. Once there, the contamination could spread quickly to thousands of people. This is a very serious concern of all water utilities. We can treat water, but we need to continue to protect it once its in hundreds of miles of water pipes, storage tanks and people's homes.

Another example is home photo developing labs. If you had a water connection into a sink full of chemicals, you've created a hazardous connection that needs to be protected with a backflow preventer.

Other examples of potential cross connections:

  • dentist's offices
  • schools (janitor buckets, clean-out hoses
  • fire stations (sometimes trucks are not filled with public water supply water)
  • hospitals
  • mortuaries


Backflow preventers (cross connection control devices prevent water from moving backwards into the water system through combinations of check valves or hydraulic breaks) can reduce this risk and protect our customers from widespread contamination. Some horror stories have been reported across the country which have involved backflow from dentist's offices, funeral homes and wastewater treatment plants. For your neighbors' and your own protection, please maintain your backflow devices as required.


Download cross connection / backflow prevention documents below. Click on a link to view it, right click on a link to download it to your computer.