Backflow is the reversal of water flow and contamination into the city's drinking water system from private properties. Backflow prevention keeps drinking water clean and safe for our community.
State regulations require the City of Boulder to maintain a Backflow Prevention Program to track the installation and annual testing of backflow prevention assemblies on all hazardous cross-connections (potential points for contamination and backflow).
Property owners who have backflow assemblies play an important role in protecting drinking water and public health for the community. We are proposing code updates to protect Boulder’s drinking water and better support compliance with state backflow requirements.
While these updates propose new fees and penalties, property owners can avoid all fees and penalties by testing backflow assemblies by the annual due date and by meeting deadlines for assembly repairs and installations. The proposed updates include:
Hang tag fees for property owners who have failed to complete the required annual backflow assembly testing within 12 months of the previous test, or have failed to install or repair an assembly by the Notice of Violation deadline.
City staff presented the proposed updates to the Water Resources Advisory Board on Oct. 21, 2024, and are scheduled to then bring the proposed updates to City Council in November 2024. If adopted by City Council, the changes will go into effect January 2025.
If you have feedback or questions about the proposed updates, please contact nobackflow@bouldercolorado.gov.
All annual test reports for backflow assemblies must be submitted online by a certified tester.
Residential single-family customers/homeowners do not have to comply with the Backflow Prevention Program requirements unless:
The Backflow Prevention Program requirements are not meant to contradict building, fire or plumbing codes, which may require a residence to have a backflow prevention assembly like those required on residential sprinkler systems. When backflow prevention assemblies are otherwise required, they must be installed, but will not be tracked by the Backflow Prevention Program.
Multi-family properties include two or more separate dwelling units served by one meter connection.
Commercial properties must comply with backflow prevention assembly installation and annual testing requirements.
All properties as described above must comply with state regulations for the installation and annual testing of backflow prevention assemblies.
View information on installation criteria and/or which backflow prevention assemblies are required to be installed and tested annually. City staff may need to survey properties to determine whether cross-connections are present, what the degree of hazard is or if approved assemblies are installed in proper locations.
The city’s Backflow Prevention Program tracks the installation and annual testing of "containment" assemblies. Containment assemblies must be installed after the meter but prior to any plumbing branches. It is possible that two containment assemblies may be required.
Other assemblies may be required inside a property by plumbing code. These are called "isolation" assemblies because they isolate internal hazards. In most cases the city does not track these assemblies. It is strongly recommended that isolation assemblies are tested annually along with containment assemblies as they can keep water inside the property safe for consumption.
Pressure vacuum breakers that are currently being used for backflow prevention on dedicated irrigation lines are acceptable as long as the assembly passes annual tests. If a pressure vacuum breaker fails and requires replacement, it must be replaced with a Reduced Pressure Zone assembly. See City of Boulder Design and Construction Standards 5.09(c)(4) for additional information.
Backflow prevention assemblies are tested by certified testers who use gauges to either add or relieve pressure to determine if they are working properly. This information is recorded on a test report for each assembly. These tests are required annually per state regulations.
Testers must hold a current certification from either The American Backflow Prevention Association or The American Society of Sanitary Engineers. Contact a plumber or contractor to find someone who can test your assembly. The city does not have a list of recommended testers.
If your existing backflow prevention assembly has been tested before, it should have a tag from the previous tester that shows the tester’s contact information.
Testers or owners are required to submit annual test reports to the Backflow Prevention Program via the online portal within 10 days of the test.
Water suppliers, testers and customers must all retain test report records for three years.
Customers should request confirmation from their certified tester that all device test report(s) for the property have been submitted through the city’s backflow portal.
The Backflow Prevention Program must be verbally notified the day the failing test is taken, and the failing test should be submitted to the city’s online portal within three days.
Failed assemblies must be repaired and/or replaced immediately. If they cannot, the Backflow Prevention Program must be notified, and a compliance plan must be established.
A failed test can result in suspension of water service if the Backflow Prevention Program determines the cross-connection represents an immediate risk to public health.
Failure to install a required backflow device or get all devices on a property tested on an annual basis may result in water service shut-off or up to a $1,000 fine.
The city is responsible for ensuring full compliance with State of Colorado backflow prevention requirements. If the city does not meet state regulations, the city’s water supply is at risk and the city may be required to notify all City of Boulder water customers that we have violated state regulations.
