Backflow Program


To ensure that Kennebec Water District (KWD) customers can turn on their faucets and find water that is free of their neighbor’s heating pipe antifreeze, toilet-bowl cleanser, or pool water, KWD wants to get the word out about backflow prevention devices.

When you turn on a spout, you expect to get safe drinking water, but will you if your neighbor has a garden hose hooked up to a bottle of liquid fertilizer or has the hose in the swimming pool or hot tub?

Federal and state law mandates the use of backflow devices by water consumers in order to contain the water that has entered their internal piping, and KWD has been working to enforce the regulations. Since 1987, KWD has been installing containment backflow devices on residential water services and requiring commercial/industrial/governmental entities to have the appropriate device installed. Most businesses now have them installed or are in the process of doing so. Only about half of the homes in the District have complied, though.

Situations such as a water main break can cause a drop in pressure that can suck the water out of a home’s or business’s internal water lines. Do-it-yourself devices, such as high-pressure power washers which may be connected to a garden hose, could force water back out into the main.

Therefore, backflow devices are required to be installed in all existing homes and businesses. The District requires all new construction to install backflow prevention devices, also.

As a customer service, KWD installs the devices at cost for homeowners in situations where the plumbing allows. In many cases, however, a licensed plumber is necessary to perform the installation.

Home and business owners alike must pay for the device on an individual basis. The cost of the device plus installation varies based on market prices. Where KWD service personnel cannot perform the installation, homeowners must employ a plumber or do it themselves.

People also need to be aware that thermal expansion can be an issue. Installing a backflow prevention device creates a closed system. When water is heated in a water heater, it expands and increases in pressure. Without a backflow device installed, heated water is pushed out the piping back into the water main. With a backflow device installed, water pressure may rise in the internal piping enough to cause faucets to drip or the temperature/pressure relief valve on the water heater to drip or blow off to relieve the extra pressure. It is advised that homeowners contact a plumber to have an assessment performed, especially if you have gas water heater.

KWD is pursuing the program not only because it’s the law but also due to public health concerns. Nobody wants to see anybody get hurt, and the dangers of contaminated water flowing back into the public water supply are very real. Dozens of documented cases have occurred across the country over the years, and several of them have occurred locally, including within the Kennebec Water District. It is generally accepted that many backflow events go unrecognized or unreported.

The purpose for this isn’t to scare people. Homeowners and industrial/commercial users should understand their liability should someone be injured or worse. Most people cooperate fully when they understand the hazard.

Some savings in certain situations may be realized as a result. Certainly, personal liability is reduced, but if a main breaks and drainage from the line occurs, water won’t be siphoned from the home and the hot water tank, in particular, which prevents damage to the heating elements.

The greater benefit from this backflow prevention program, however, is that people will be better protected from an inadvertent backflow event from their neighbors.