Who approves and owns an underground fire line in the Valley?

A fire line carries water from the city main to the fire protection system: the sprinkler riser, the standpipes, or a private hydrant loop. It exists for one purpose, and the city treats it that way. The Phoenix Fire Line Plan Offsite Checklist says a fire line connection to the city main "shall be used for fire protection system only" and that no metered service can be connected to a fire line.

That is why fire, domestic and irrigation demands each get their own connection. The Phoenix water meter sizing guideline prohibits combination fire, domestic and landscape meters and says each demand needs its own connection. If a building has been running off one pipe for everything, or a neighboring property shares a fire line across the property line, expect the city to require separation when you open the street. The checklist points the other way as well: each site ties directly to city services without a fire line shared across property lines.

The size of the fire line comes from the fire protection design, not from the domestic fixture count, so a modest building can still need a large underground pipe.

Two groups, split by where the pipe sits.

The city's Planning and Development Department reviews the offsite portion, meaning the pipe from the city water main to the property or easement line. The checklist says its purpose is to comment on plan design "from the city of Phoenix water main to the property or easement line." The designer signs a certification that the plans meet city standards, and the reviewer checks the design against the Water Services design standards manual, the Maricopa Association of Governments (MAG) standard details and the city supplement, the Phoenix amendments to the Uniform Plumbing Code, the International Fire Code and NFPA 24.

The onsite portion goes through a separate plan review. The checklist says onsite fire lines "must be reviewed and permitted under a separate plan submittal" to Planning and Development, Fire Plan Review. On the fire side, Phoenix Fire Code Section 105.6.26.10 requires a construction permit for the installation or modification of fire lines that serve fire protection systems.

Practical points from the checklist that affect a repair or a new connection:

1. 1Any cut in the street needs asphalt restoration under the city's pavement cut policy.
2. 2Inspection staff must be notified 48 hours before construction begins.
3. 3Plan review approvals are valid for 12 months, and expired reviews cost extra to reinstate.
4. 4Underground work near other utilities needs the Blue Stake notification decal on the plans.

The city does not let just any licensed contractor touch a fire line. Phoenix Fire Code Section 105.7 sets up a business certificate for qualified contractors that "install, modify, alter, add to, test, repair, provide required inspections or service" a fire main, sprinkler system, standpipe or similar system. It adds that fire protection system construction permits "shall only be issued to current business certificate holders."

To qualify, a contractor needs a current Arizona Registrar of Contractors license and a state privilege tax license, and must show knowledge of the standards. The Fire Code says the fire code official may accept NICET Level 3 or 4 certification in the category of "underground fire mains and hydrants," a professional engineer, or a passed exam.

The takeaway for an owner is simple. Ask any contractor to show the Phoenix certificate before you sign, and ask who pulls the fire permit. A plumber who is excellent at domestic water is not automatically eligible to work on a fire main in the city. HQ Plumbing & Air provides fire and domestic backflow assembly testing, certification and filing. Sprinkler-system installation, testing, inspection and certification are separate work that HQ does not offer. We repair underground fire lines only outside the City of Phoenix; fire-line work inside Phoenix must go to an appropriately qualified contractor.

Plan-review limits and maintenance responsibility are different boundaries. The pipe in the public right-of-way is built to city standards and is connected at the city main by a wet tap. The checklist requires fire line pipe to be minimum pressure class 350 ductile iron within the public right-of-way or public easements, and on site up to the customer's side of the backflow device.

The backflow assembly is a required protection point; its location does not establish the maintenance handoff. The checklist requires backflow prevention on all fire lines, installed "outside of right-of-way at (or near) the property line (point of service)" and fully accessible for testing, repair and replacement, with at least three feet of unobstructed space around it. Pipe on the customer's side of the assembly "shall conform to the Uniform Plumbing Code."

The Phoenix Design Standards Manual, Water section E, calls a fire line a private pipe system connected directly to the city water system. It places all private fire-line maintenance responsibility on the owner beginning at the control valve in the public right-of-way or water easement. Do not infer city maintenance simply because a section is outside the property line or before the backflow assembly. Have Phoenix Water Services confirm the assets and boundary for the address before excavation. Where the pipe crosses the sidewalk or street, a right-of-way permit is usually part of the picture, as covered in our page on the permit to dig in the right-of-way in Phoenix.

The job is not finished when the pipe is in the ground. The checklist requires a formal written request for a fire line turn-on from Phoenix Fire Prevention, sent to Civil Engineering in Planning and Development, once the work is complete. The line is then turned on by the Water Services Department. Until that request is made and acted on, the checklist says the job is not complete.

If the onsite work does not happen at the same time as the offsite work, the checklist requires a tapped cap with a ball valve, rated 300 psi or greater, at the end of the offsite work, installed before the backflow device.

Phoenix City Code treats the backflow assembly on a fire line as the customer's responsibility. Section 37-143 requires the customer to test backflow assemblies at least once a year, and for fire lines and fire sprinkler systems "the initial and annual test must be performed by a certified tester who is also permitted by the City Fire Marshal" and must include a full flow test. Section 37-144 adds that results go to the city on approved forms within 30 days, and a failed assembly must be repaired as the Fire Code requires.

Owners often miss the annual date. If your building has a fire line, make sure someone on your side knows who holds the test schedule, and keep the certificates. The related question of backflow on domestic water is covered in commercial backflow testing requirements in Arizona.

The structure repeats: the water utility taps the main, a plan review covers the line in the public way, the fire authority permits and inspects, and backflow protection sits at the property line or riser. Scottsdale's design manual, in its 2009 version, says fire lines connect by saddle or tee and valve, need backflow protection at the riser or at the property line, and are not connected to transmission mains of 14 inches or larger. That manual is dated, so treat it as an outline and confirm with the city. Forms, fees, contractor certificates and who owns what between the main and the backflow device differ, so ask the local fire and water offices before you commit to a scope.

1. 1Find the fire line on your as-builts, or have a locate done, so you know the pipe's size, depth and where it crosses the property line.
2. 2Confirm with the city whether the problem is on the city side or the property side.
3. 3Hire a contractor who holds the fire certificate the city requires, and confirm that the permits will be pulled in that firm's name.
4. 4Line up the annual backflow and flow test before the work, so the repair does not leave you out of compliance.

If the trouble is with the domestic water service or the property-side plumbing around it, call HQ Plumbing & Air any time, day or night. We are licensed and insured, and estimates are free. HQ provides fire and domestic backflow assembly testing, certification and filing. We repair underground fire lines only outside the City of Phoenix. We do not install, test, inspect or certify sprinkler systems. Rules and forms change, so check the city's current requirements before you start.