Across the U.S., many water jurisdictions still rely on outdated installation methods for backflow prevention assemblies, often placing devices in below-grade vaults or inside buildings. These legacy approaches may seem familiar, but they come with steep consequences: safety hazards, high maintenance costs and the looming risk of property damage or contamination.
The problem isn’t lack of effort, but lack of guidance. Local jurisdictions may not provide clear standard details for outdoor, above-ground backflow enclosure installations, so engineers default to the last spec they used, perpetuating unsafe and inefficient designs.
Now’s the time to change that. Leading municipalities demonstrate that standardized above-ground designs reduce risk, save money and streamline approvals. Here are 10 compelling reasons every water jurisdiction should adopt above-ground aluminum enclosure standards.
Vaults are inherently dangerous. OSHA classifies them as confined spaces, requiring extensive safety protocols just to enter. Technicians face risks from poor air quality and injuries. At worst: death.
By contrast, above-ground aluminum enclosures eliminate the need for confined space entry altogether. Technicians can access backflow devices quickly and safely, reducing labor costs and the chance of workplace injuries.
Water jurisdictions are tasked with protecting the drinking water supply from contamination, but when backflow prevention devices are installed in vaults, that mission is compromised.
Flooded vaults can submerge valves and test cocks, creating dangerous cross-connections. After Hurricane Harvey, for example, Houston experienced widespread vault failures, putting water systems in jeopardy. Above-ground enclosures mitigate this risk by keeping equipment dry and functional.
When reduced pressure zone (RPZ) assemblies fail indoors, they discharge water at the rate of hundreds of gallons per minute. That kind of flooding can destroy property and trigger insurance claims or lawsuits.
Placing backflow preventers outdoors in enclosures designed for drainage completely removes indoor flood risk. Traditional underground installations in vaults may also flood, making above-ground enclosures best. Marine grade aluminum enclosures certified to ASSE 1060 ensure proper water evacuation and prevent structural damage.
Testing submerged or hard-to-access devices takes more time and increases labor costs. It may even reduce test accuracy. Above-ground enclosure installations, with ease of access, improve long-term serviceability and speed up testing.
Testers can complete many more inspections per day when equipment is at the curb on a concrete slab, not hidden behind locked doors or buried underground.
Backflow preventers aren’t cheap, with some assemblies costing thousands of dollars. But when housed in wet, corrosive vault environments, they degrade quickly. Dry, insulated, above-ground enclosures provide maximum protection for sensitive components from freezing conditions or rust, prolonging service life and reducing replacement frequency.
Another consideration is keeping vandalism at bay. Backflow cages aren't preferred and can actually become targets for theft.
Lack of standard details for enclosures causes confusion. Engineers waste time guessing what’s acceptable, resulting in multiple submittals and delayed approvals.
By adopting a published set of standard details, water jurisdictions make the design process more efficient for everyone involved. This reduces miscommunication and improves project timelines. Plus, above-ground enclosures may lead to long-term cost savings on repairs and maintenance requirements.
ASSE 1060 certification isn’t optional. It’s the industry standard to meet minimum performance thresholds for freeze protection, drainage and access.
Standard details should call out ASSE 1060 Class I enclosures, which are heated and maintain internal temps of 40°F even when it’s -30°F outside. These specs are crucial in cold-weather jurisdictions, so insulated aluminum enclosures should be clearly defined in every jurisdiction’s policy.
Some water professionals may hesitate to install equipment above ground due to appearance, but modern designs eliminate this concern. Smaller N-type assemblies reduce enclosure size by up to 25%, and enclosures now come in a wide variety of colors, finishes and even vinyl wrap designs and custom graphics.
Strategic placement and landscaping further minimize visual impact, allowing enclosures to blend seamlessly into the site without sacrificing function. And a custom enclosure gives easy access to the backflow assembly while taking up a minimal footprint, helping to save hundreds on material costs.
Many jurisdictions are moving the water meter into the same above-ground enclosure as the backflow preventer. This configuration makes sense: it simplifies installation, protects both components and speeds up maintenance and testing.
With removable roof panels and clear access guidelines, these backflow enclosures allow quick removal and replacement of meters and valves, all while avoiding the dangers and limitations of vault access.
Cities like Arlington, Tex., and Las Vegas, Nev., are already ahead of the curve. Arlington published a full set of standard details to guide safer, more consistent backflow designs. Las Vegas eliminated vaults and now installs meters and backflow assemblies in one streamlined enclosure, saving $60,000 per install in some cases.
Their example shows what’s possible when municipalities prioritize safety and efficiency over habit.
The risks of underground and indoor installations are both real and avoidable. Adopting standard details for above-ground enclosures is a smart, cost-effective way to protect your infrastructure, your team and your water supply.
Download our free Standard Details Guide, including five editable CAD templates and many more examples of how to implement standard details for your jurisdiction today.