Backflow is the term plumbing professionals use for contaminated or unwanted water that flows in the wrong direction. It is considered a plumbing emergency because backflow can present serious risks to your health as well as result in property damage, potential fines, and legal issues. In light of this, homeowners might wonder how to keep backflow from occurring. The answer lies in a correctly installed plumbing system equipped with a backflow preventer.
Below, we dive into the ins and outs of backflow prevention and answer the following common questions such as:
- Why does backflow happen?
- What is a backflow preventer used for?
To find out more, read on!
Why Does Backflow Happen?
As mentioned, backflow is the reversing of unwanted water into the main water supply. It can occur wherever there is a cross-connection between potable (suitable for drinking) and non-potable (not suitable for drinking) lines.
A cross-connection is a direct or potential link between clean water piping and a contamination hazard or source. One example of a direct cross-connection is when a water supply line is linked directly to a boiler or a sewage line.
Meanwhile, an example of a potential cross-connection is a faucet that ends below a sink’s flood level. If the sink becomes clogged, the faucet becomes submerged in the dirty water. Then, if negative pressure develops in the potable water supply, contaminants could end up siphoning into the water supply.
Backflow usually has two leading causes. These are back pressure and back siphonage.
- Back Pressure: This is when the pressure inside the non-potable system is greater than the pressure in the potable system. This difference in pressure pushes the wastewater or contaminated water into the potable supply line. Back pressure may occur in pumps, boilers, fire sprinkler systems, and other pressurized systems where there is a direct connection between a potable water pipe and a contamination source.
- Back Siphonage: This is when the water supply pressure falls below zero. An unexpected decrease in pressure can cause a non-potable source, such as a sewer line, to be pulled into the clean water line.
Back siphonage usually happens when the water supply stops due to breaks or repairs in the city’s water mains. It often occurs in toilets and sinks.
Here is a hypothetical example of how a back-siphonage can occur: a bathtub on the second floor of a home is full of dirty water, submerging the inlet. Nearby, firefighters open a hydrant that’s connected to the same water supply. This causes negative pressure in the water supply line to the house, resulting in the inlet sucking out the dirty bathroom water and sending it back to the clean water supply using the bathtub’s inlet.
What Is a Backflow Preventer?
As the name suggests, a backflow prevention device is composed of a series of check valves. It is installed in plumbing systems to prevent backflow by keeping water flowing in only one direction and stopping contaminated water from reversing course and entering the main water supply.
A backflow preventer works by maintaining differences in water pressure. In the event of a drop in pressure within the main water supply, the backflow preventer closes off, keeping water from the user’s system from reversing its course and blocking it from the clean water supply.
There are many kinds of backflow preventers, and which one is used depends on the application. For instance, a reduced pressure zone (RPZ) backflow preventer is typically used in industrial settings, while the double check valve assembly (DCVA) is more common in residential and commercial properties.
Atmospheric vacuum breakers (AVBs) are also often used in homes. These simple yet effective backflow preventers create an air gap, preventing water from flowing back into the supply.
Why You Need a Backflow Preventer
Some new homes already have backflow prevention devices installed. But what if yours doesn’t? What is a backflow preventer going to do for your home, and why should you get one?
Here are some important reasons:
- Health Protection: Backflow issues pose a serious health risk. Without a preventer, contaminated water, possibly carrying sewage, can reverse its flow into your clean water supply lines. Bacteria and other pathogens from sewage can find their way into your drinking water, potentially leading to illness and impacting the well-being of your household.
- Property Preservation: Backflow isn’t just a health concern; it can also wreak havoc on your property. Contaminated water with high levels of minerals, chemicals, or even sewage can stain and corrode pipes, fixtures, and appliances. Meanwhile, faulty valves caused by backflow can result in leaks, which can result in water damage and create the ideal environment for mold and mildew.
- Regulatory Compliance: Many local regulations require homeowners to have backflow preventers installed. Failing to comply may result in legal consequences and fines. A preventer ensures you abide by these regulations, helping you avoid legal issues.
Finally, installing a backflow preventer provides peace of mind. Knowing that your water supply is protected from contaminants offers reassurance, creating a safer and healthier living environment for you and your loved ones.
Trust Your Local Plumbing Experts For Expert Backflow Prevention
Bluefrog Plumbing + Drain of Overland Park serves residential and commercial clients, providing them with plumbing solutions they can rely on. We offer complete backflow services, including equipment installation, maintenance, and repair, as well as water testing. Contact us today to book an appointment!