Backflow Testing in Longmont, CO

Longmont's Backflow Prevention and Cross-Connection Control Program requires assemblies to be tested every year by a certified tester and again after installation, repair or relocation, with results filed through the City's SwiftComply portal; new or replacement assemblies must be RPZ type unless the City approves otherwise. For a test, a repair or a new assembly, call the number on this page to be connected with a local plumber in Longmont.

Does a Longmont single-family home need backflow protection?

Sometimes. Longmont surveys every connection that isn't single-family. For single-family homes, an assembly may be required on a dedicated irrigation line, a fire suppression system or a boiler. If your home has a separate irrigation service, expect it to need protection rated for high hazard, because Longmont classifies irrigation that way.

The program sits in Longmont Municipal Code 14.06, and the City's water utility runs it. Longmont's water is soft and chlorinated, drawn from the St. Vrain creeks and Colorado-Big Thompson water, so scale isn't usually the reason a device fails here; freeze damage and debris are more common.

Why does Longmont want an RPZ instead of a double check?

Because irrigation is high hazard. A reduced pressure zone (RPZ) assembly has a relief valve between two check valves that dumps water to the outside if either check leaks, which offers more protection than a double check. Longmont requires new and replacement assemblies to be RPZ type unless the City approves something else. Installing one also takes a miscellaneous permit from Building Inspection at the Development Services Center, 385 Kimbark Street (303-651-8332).

An RPZ needs a spot where its relief valve can discharge without flooding anything, which matters if you're replacing an older device in a basement.

When is a test required besides the yearly one?

Longmont wants a test after installation, after any repair and after the assembly is relocated, on top of the annual test. All results go through SwiftComply. If a plumber rebuilds your device in April, plan on that test counting toward the year, but confirm with the City.

When you call, say whether the device is on a dedicated irrigation line, a fire system or a boiler, and whether it's an RPZ already. If it isn't and it needs replacing, the plumber can explain what the RPZ rule means for location and drainage, and handle the miscellaneous permit.

Call now to be connected with a local plumber in Longmont.

(303) 529-9880

Local note

Longmont's newer neighborhoods like Prospect New Town and the subdivisions off SH 119 have plenty of irrigation, while older homes near downtown Main Street may have sprinklers added later. About 37% of homes were built before 1980. Either way, an outdoor RPZ needs draining before Longmont's freezing nights.

Backflow Testing questions in Longmont

What separates an RPZ assembly from a double check?

An RPZ adds a relief valve between two checks that discharges if protection fails, so it handles high-hazard lines. Longmont requires RPZ type for new and replacement assemblies unless the City approves otherwise.

Is a permit needed to add or replace a backflow preventer?

Yes. Longmont requires a miscellaneous permit from Building Inspection for new or replacement assemblies.

Where do the test results go once the test is done?

Into the City of Longmont's SwiftComply portal, for the annual test and for tests after installation, repair or relocation.

Does a home fire sprinkler or boiler change the backflow rules?

They can. Longmont says single-family homes may need assemblies for fire suppression systems or boilers, as well as dedicated irrigation lines.