Backflow is the undesired reverse flow of used water back into the public water supply, which can be dangerous in certain circumstances. Therefore, backflow prevention devices are required on all industrial and commercial properties, including fire sprinkler systems, irrigation systems, and multi-family residential units. They are also needed on residential lawn sprinkler systems. 

Backflow prevention devices require annual testing to ensure that your employees and the general public are not exposed to water contamination. Therefore, most property owners with a backflow prevention device must inspect these devices annually. 

Why Does Backflow Occur and How Do Backflow Prevention Devices Stop It?

Backflow occurs due to pressure changes. It is commonly seen when the pressure in the hoses changes, such as pipes freezing, burst water main, or when multiple fire hydrants are opened simultaneously. Due to reduced pressure, the water is no longer pushed forward and may flow backward. 

During events like this, non-potable water may flow back into the usable water supply, potentially leading to a significant health threat. When water flows backward, it can be contaminated with:

• Soap from sinks, dishwashers, and showers.
• Chlorine and other chemicals from pools and spas.
• Animal waste.
• Human waste.
• Fertilizers, herbicides, and pesticides applied to lawns or crops.

Backflow prevention devices serve as a gate to prevent contamination in the water supply. They allow water to flow into buildings but stop it when it flows backward. There are several types of backflow prevention systems, including: 

• Atmospheric vacuum breakers
• Pressure vacuum breakers
• Double-check valves
• Reduced pressure principle backflow assembly

Each of these systems works uniquely to prevent the backward flow of contaminated water into the water supply. However, the right system for your needs may depend on multiple factors, such as the plumbing system, installation and maintenance needs, and state or local regulations. 

Why Do Backflow Prevention Systems Need to be Inspected Annually?

While backflow prevention systems are critical in keeping the water supply clean, they are not effective 100% of the time. Like other emergency equipment, these systems need regular testing to spot any issues with the system and address it before a major catastrophe occurs.

Many issues with a backflow prevention system can be discovered during backflow testing, each of which would be disastrous. Common problems with these systems include:

• A faulty first check valve or second check valve – If these valves are damaged or inoperable, they can cause a change in pressure resulting in backpressure. This scenario can introduce direct cross-contamination in the water supply.
• A relief valve is opening too high or too low – If the valve is too high, it can create numerous problems within the critical parts of the backflow prevention system. When this occurs, there is potential to cause pressure changes that may result in backflow. On the other hand, if the valve is too low, something restricts its movement, which may be caused by corrosion or scale.
• Wear and tear – Like any other equipment, backflow prevention systems are susceptible to wear and tear as they age. Additionally, many inexpensive backflow prevention devices are used in residential settings that are only designed to last a couple of years. Therefore, aging backflow prevention devices must be replaced before they stop functioning correctly. 

In addition to averting a major disaster, backflow prevention inspections are also mandated in many states. Therefore, completing an annual inspection can help your company comply with regulations. 

Legacy Fire can help customers understand options for backflow prevention and the process of completing an annual inspection. For more information, contact Legacy Fire today.