In a recent blog, the reasons for the growing trend of locating the water meter inside the enclosure along with the backflow preventer were outlined. A primary reason for this growing trend is water jurisdictions are recognizing the below-grade meter vault is a confined space, which poses a safety risk for anyone performing testing or routine maintenance on the water meter or the backflow preventer. One other reason for this growing trend is the ability to reduce the overall required footprint for the water meter and backflow preventer when space on a project is limited.
In this blog, we will take a look at a recent project and how the costs compare when the meter is moved from the meter vault to the backflow cover.
The project is located in the northeast. The water jurisdiction provides a standard detail where the water meter and backflow assembly are installed in an ASSE 1060 Class 1 enclosure. The contractor was installing an 8” water meter and an 8” backflow assembly. These figures were provided by a utility contractor. In this example, the cost was almost the same.
Cost If the Water Meter is Installed in a Vault
8” meter vault including valves but not installed - $11,200 contractor price
Backflow cover for 8” backflow assembly - $6,500 contractor price
Concrete slab for backflow assembly enclosure - $1,500 contractor price
Total Cost - $19,200
Cost If the Water Meter is Installed in the Backflow Cover
Larger backflow cover required for meter and backflow assembly - $13,200 contractor price
Additional gate valves and fittings - $2,700 contractor price
Larger concrete slab required for larger backflow enclosure - $3,000 contractor price
Total Cost - $18,900
Two additional costs not considered in the comparison that should be considered in the cost evaluation:
- The labor and equipment savings (boom truck for the vault) related to digging a hole for the meter vault as compared to a pipe width ditch if the water meter is installed inside the backflow cover.
- The lead time for the backflow cover is less than the lead time for a meter vault in most locations across the U.S.
Meter Trends – Make the Enclosure Smaller
Some water jurisdictions are changing to ultrasonic meters for applications requiring a 3” meter or larger. This type of water meter eliminates the need for long straight pipe runs before and after the meter. And when these straight runs are eliminated, the backflow cover does not need to be as long.
On a recent project, the length of the backflow cover was reduced by 48” due to the use of the ultrasonic meter. This created sizable cost savings for the project.
What Should You Consider?
As a design engineer, look for the best practices for meter and backflow preventer design. Change is not easy and requires a commitment to pursue what is best. Reach out to us if you want to talk about your next project. When it comes to water jurisdictions, we’ve worked with several across the county and would be willing to provide our support as you make these changes in your jurisdiction. Reach out to us and we’ll be glad to help you make these important changes.