Every City of Littleton resident is served by Denver Water, and Denver Water's Cross-Connection Control program requires approved backflow assemblies to be tested at installation and every year by a certified tester. If you need a test, repair or replacement, call the number on this page to be connected with a local plumber in Littleton.

Whose backflow rules apply in Littleton?
Denver Water's. The City of Littleton says all of its residents are served by Denver Water and that the city's Public Works Department doesn't provide water. So the backflow program that applies inside city limits is Denver Water's. That program requires approved assemblies on commercial, industrial, irrigation and fire line services, assesses single- and multi-family homes by site hazard, and calls for tests at installation and every year after by an ABPA or ASSE certified tester, with results reported to Denver Water's Cross-Connection Control office.
One caution: Littleton ZIP codes such as 80120 through 80123, 80127 and 80128 also cover unincorporated areas like Columbine, Ken Caryl and Highlands Ranch, which have other water providers. If your address is outside city limits, your provider's rules apply instead.
Does my house need a backflow test?
Denver Water decides based on what's connected. An irrigation system is the most common reason a Littleton home has an assembly, followed by a well, pond or other auxiliary supply, which always calls for one. Littleton grew fast in the 1950s and 60s, and many of those houses had sprinklers added later. If you're not sure whether yours is protected, a plumber can find the tie-in and tell you what's there.
Ask the plumber you're connected with whether they hold ABPA or ASSE certification, since Denver Water only accepts results from certified testers. Irrigation assemblies on Denver Water service are tested between May and September, so book early in the season if you want room for repairs.
Do I need a city permit for backflow work?
Likely. Littleton requires permits to install, alter, repair or replace any plumbing system within city jurisdiction, through the Permit Center (303-795-3751). Homeowners doing their own single-discipline work sign a Homeowner Affidavit. Addresses with a Littleton mailing address outside city limits go to their county instead.
Local note
Water and sewer are separate in Littleton. Denver Water handles water, including emergencies at 303-628-6801 after hours, while sewer is a City of Littleton service treated at South Platte Renew. A leaking backflow device is a water issue; close the irrigation shutoff and call a plumber.
Backflow Testing questions in Littleton
How often does a backflow assembly need to be tested here?
Who is qualified to run the test on my assembly?
Is a permit needed to add or replace a backflow preventer?
My property has a private well. Where does backflow fit in?
More plumbing services in Littleton
Backflow Testing nearby
Helpful guides
Sources
Last updated: