Ensuring the safety and efficiency of water systems hinges on the correct installation of backflow preventers. Surprisingly, many designs still use outdated methods, such as placing backflow prevention assemblies in underground vaults or in backflow cages — a practice fraught with safety hazards and financial drawbacks.
By adopting standardized details that advocate for above-ground enclosures, you can significantly mitigate risks, prevent potential flooding, and achieve substantial cost savings.
Considering Details for Backflow Enclosure Design
Very few water jurisdictions provide standard details for backflow preventer enclosures. As a result, designers don’t search for these details or even consider designing above-ground enclosures. Designers fall back on what they know will be approved, even though the design may not match best practices.
By not exploring other options, designers may not realize that insulated backflow enclosures (outside and above ground) are not only cost-effective, but also eliminate unnecessary risks. The design of your backflow cover must be well thought, and designers should exude strong attention to detail when it comes to backflow preventer assemblies.
5 Ways the Location of Backflow Preventers Impacts Safety and Cost
Here are five reasons why choosing the right location for your backflow preventer matters so much for building owners and water customers.
1. Outside, Above-Ground Backflow Enclosures Are Safer
The first thing to consider is how much safer it is to house your backflow preventer assembly in an outside, above-ground backflow enclosure.
If the backflow preventer assembly is installed in a vault, the water customer now has a confined space on their property as defined by OSHA. Many of these customers will be completely unaware of the vault on their property, let alone the risks and responsibilities related to the confined space.
As a water jurisdiction, you probably have policies and procedures in place related to entering a confined space and may conduct routine training to prevent accidents. Your water customer probably does not have these safeguards in place.
As we look at vault installations across the country, rarely do we see any signage warning a person to stay away from the vault. Imagine a person innocently opening the vault lid and the problems this could create!
In the event of an injury or death, many people could face lawsuits, including the:
- Building owner
- Designer
- Water jurisdiction
By designing a backflow enclosure, you avoid this unnecessary risk. Ask the water jurisdiction to provide a standard detail for outside and above-ground backflow preventer installations. That way you can avoid the vault and provide peace of mind.
2. Backflow Enclosures Eliminate Flood Risk
Not only are outside, above-ground backflow enclosures safer, they also eliminate flood risks, too.
In fact, we typically find out during our presentations that many mechanical and plumbing engineers are unaware of the significant flood risk that exists if a catastrophic failure occurs.
Over the past four years, we've found most designers think the floor drain will be enough to handle any water that discharges from the relief valve. This is not the case.
The reduced pressure backflow preventer will release water when it’s doing its job, which is to protect drinking water. All it takes is a little debris to start the discharge process, which could be as much as a foot of water every 10 minutes. Why would any building owner want this potential problem inside the building when a better solution is readily available?
We anticipate the day when the insurance industry figures out the reduced pressure zone (RPZ) actually causes floods. Insurance industry-leaders will ask, "Why was it designed and installed inside the building?"
You can avoid flood risk by using backflow enclosures located outside the building. Ask the water jurisdiction to provide a standard detail for outside and above-ground backflow preventer installations.
3. Decrease Cross-Connection Risk With Backflow Preventer Enclosures
The purpose of the backflow preventer is to stop water from returning to the distribution system during back siphonage or back pressure events. But when installed in a vault that floods, the test cocks of the assembly can become submerged, creating a potential cross-connection. That risk defeats the very purpose of the device.
The contaminated water in the vault can be drawn into the water customer's lines or drawn back into the water distribution system through pressure vacuum breakers. Think about how long a vault will be filled with water after flooding disasters. And we seem to have more and more of these disasters in many locations across the U.S.
To eliminate this threat, don’t design the backflow prevention assemblies inside a vault. Instead, request that your water jurisdiction provide a standard detail for outdoor, above-ground installation preferably in backflow preventer enclosures. This best practice not only removes the risk of submerged assemblies, but also simplifies maintenance, testing access, and code compliance.
Keep in mind: vaults were originally intended for fire protection systems. When cross-connection risks rise, the liability and cleanup costs fall on the property owner or engineer. Designing safer, more accessible, and weather-resistant installations above ground is the proactive, modern solution.
4. Insulated Aluminum Enclosures Are Cost Effective
Designing a backflow enclosure that's outside and above ground actually saves you money. Aluminum enclosures typically cost less than underground utility vaults for several key reasons:
- Lower installation costs: They only require a concrete pad, not extensive excavation or concrete construction like vaults.
- Reduced maintenance: Vaults can cost up to $5,000 annually to maintain due to safety requirements, deterioration, and confined space regulations.
- Faster installation: Aluminum enclosures can be installed and operational in as little as one week, while a full vault rehab can take a month or more.
- Fewer safety hazards: Vaults are classified as confined spaces and carry high liability risks, which can translate into greater long-term costs.
Just how much can you save? In Las Vegas, the water district discovered they could save up to $60,000 by using above-ground aluminum enclosures instead of underground vaults.
Now consider if you install in a vault. First, installing a backflow assembly in a vault costs the water customer several thousand dollars.
When the vault is filled with water (which happens more than you might think), the assembly will be subjected to standing water — sometimes on an ongoing basis or for months — which shortens its lifespan. The epoxy coating on the gate valves and on any grooved couplings will quickly deteriorate because the assembly is not designed to be underwater. Gasket life is also shortened, which means the water customer may end up replacing expensive backflow prevention devices prematurely. And, vaults do not offer frost protection or climate control from freezing conditions for the pipes and RPZ.
If the device is installed above ground inside an ASSE 1060 insulated backflow enclosure with a proper locking mechanism, it will stay dry and the customer will avoid those additional expenses.
5. Backflow Enclosures Protect Your Backflow Assembly
The bottom line is that backflow preventers play an important role in clean drinking water. Unfortunately, the backflow preventer enclosure gets little thought during design on most construction products. Designers are pressed for time to complete the drawings and often use the same design they’ve had for years.
As you now know, considering the location of backflow prevention assemblies is very important. The best location is outside the building in an above-ground ASSE 1060 insulated aluminum enclosure.
Worried about freeze protection? You can still protect from freezing temperatures using insulated, marine grade aluminum enclosures. Choose from a slab mounted heater or wall heater. Workers will appreciate easy access to equipment, while keeping vandalism at bay thanks to our added security locks, LOCK-360 and MUNI-LOK. (Backflow cages are now a target of thieves and should be avoided.)
Ready to Upgrade Your Backflow Cover?
Contact us to see if we can help you with your design. If you're a water jurisdiction, we'll improve your standard details. We can provide many examples and work with you to develop a comprehensive set of details for your jurisdiction.
Don't assume backflow covers have to be an eyesore! You can get design ideas by looking through our Enclosure Aesthetics Guide.
.jpg?width=206&name=MadeInUSA-Icon%20(1).jpg "MadeInUSA-Icon (1)")
