What is Backflow Testing?

If you are on city water, your plumbing is connected to the water supply of all your neighbors in your town. Keeping that water clean and healthy is a top priority for everyone, which is why backflow devices are often required. Backflow prevention is key to ensuring that toxins from your home and property do not go back into the community water, helping protect against contamination. Using a backflow prevention device and having backflow testing are part of ensuring safe water for you and your neighbors.

Backflow devices, referred to as RPZ or Reduced Pressure Zone devices, ensure that if something causes a change of pressure in your plumbing, it does not result in backflow into the main water pipe or supply. A leak in your plumbing, use of hydrants for fires, boiler problems or other issues can cause a pressure difference that sucks water from your plumbing into the main line. RPZ devices protect against this from occurring, stopping contaminated water with bacteria, minerals and chemicals from your property from entering the water supply.

Annual Backflow Testing

If you are required to have a RPZ due to a boiler, irrigation system or hydrant on your property, the device needs to be regularly tested for quality. Many municipalities or states require backflow testing at least once a year to ensure the RPZ will work if a water pressure fluctuation occurs. This testing needs to be preformed by a licensed plumber and you may need to submit the results to avoid fines or penalties in your area.

Clean, healthy water is important to everyone. If you have a backflow device at your home or business, make sure you schedule annual backflow testing to protect your local water supply.

Posted on behalf of:
Kiddco Plumbing, Inc.
106-M Oakgrove Road
Sterling, VA 20166
(703) 435-4441

What Do Backflow Prevention Devices Do?

A backflow prevention device is a common method of protecting our drinking water supplies from contamination.  Not all water authorities require backflow prevention devices, but if you live in an area where backflow prevention devices are required by local municipal codes, it is important to understand what role they serve and how to keep your backflow prevention device in good working order.

In general there are two types of municipal water supply systems:  open systems and closed system.  A typical municipal water supply system supplies water to homes and businesses through water supply lines connected to the municipal water main. Most of the time, the water pressure coming from the water supply is much higher than the water pressure in the home so water flows from the supply into the home.

However, under certain circumstances such as a broken water main or some other event that causes the municipal water pressure to drop, water can flow backwards from a home or business into the water supply.  A water system that can flow in either direction is called an open system.

In a closed system, a backflow prevention device prevents water from flowing backwards from the home or business into the water supply lines and helps protect the water supply from contamination.  In a home, water in irrigation sprinkler systems can become contaminated by pesticides and fertilizer.  In addition, if the home has an automatic pool filling device, the water can become contaminated with chlorine and other pool chemicals.

Backflow prevention devices can only do their job if they are regularly tested by a knowledgeable plumber.  Where backflow prevention devices are required by local ordinance, backflow testing is often required by law.  Even if it is not required by law, it is good practice to have your backflow prevention device tested annually.

Backflow Testing Keeps Drinking Water Safe

Fertilizer. Fire protection chemicals. Pool chemicals. Weed killer. These are among the toxins that can make their way back into your drinking water at home, which is why backflow testing is required by many municipalities.

Water is at risk of flowing backward and into the water system – which contaminates your drinking water — when the pressure in a water system isn’t maintained. Backflow testing helps prevent that.

Water systems are designed so that the water flows in only one direction, thanks in part to water pressure. Water pressure is what keeps the stream flowing from the water supply to your home. However, the water, could potentially change direction if the water pressure in the water supply system loses strength. Water in sprinkler systems, fire suppression systems, pool water feed systems, and other sources could flow backwards into the water supply lines.  When the water pressure is restored this contaminated water could wind up in the drinking water of your home.

A backflow prevention device keeps dirty or contaminated water from flowing backward into the water supply.  There are two types of common backflow devices: an air gap and a check valve. An air gap connects to your plumbing system from your water storage area; a check valve forces the water to flow in only one direction, thereby keeping it out of your home.

Water can actually flow backward when the water pressure is low. That’s why many municipalities require yearly backflow testing by a certified agency and are required to have a backflow prevention program in place to check for water purity.  Annual backflow testing ensures your backflow prevention devices are working properly and helps protect the potable water supply.