What flow rates does Mesa allow for commercial faucets, toilets and urinals?

Mesa adopts the 2024 International Plumbing Code and amends it in City Code 4-5-2. Under Chapter 6, Table 604.4 is reprinted with Mesa's values. The quote above is one row. The whole table:

Three footnotes come with it. A hand-held shower spray is a shower head. Consumption tolerances are determined from the referenced standards. And shower heads must comply with all requirements for high-efficiency showerheads in ASME A112.18.1-2020/CSA B125.1.

The city's plumbing plan review checklist turns the table into two plan items: provide low flow fixtures, and show that maximum flow rates and consumption for fixtures and fittings comply with the Mesa table. Both cite the section as M-IPC 604.4, which is the city's name for the amended code.

• gpm: gallons per minute, measured at the stated pressure. A faucet is rated at 60 psi, a shower head at 80 psi.
• Metering faucet: a faucet that shuts itself off after a set quantity. Its limit is per cycle, 0.25 gallon, not per minute.
• Public and private lavatory: the table does not define them. Our reading is that a lavatory in a restroom open to customers or the public is public, and one in a private bathroom, such as a dwelling or a single occupant office suite, is private. Ask the plan reviewer which one your sink is.
• Flushing cycle: one flush. The table says the quantity is per cycle, so a urinal's limit is the water used on each flush.
• M-IPC and M-IRC: the city's shorthand for the Mesa Plumbing Code and Mesa Residential Code.

Anyone installing or replacing the fixtures in the table in a Mesa building under the plumbing code: restaurants, offices, retail, warehouses with restrooms, clinics. The city's plan review checklist lists the table as a plan item.

It does not cover homes built under the residential code. Mesa's residential amendment carries a separate table, P2903.2: a lavatory faucet at 1.5 gpm at 60 psi, a shower head at 2.0 gpm at 80 psi, a sink faucet at 1.8 gpm at 60 psi and a water closet at 1.28 gallons. That section also has an exception for replacing existing fixtures that do not require a permit. The commercial table quoted here has no such exception in the text we read.

A new office suite. The plan set shows lavatories in the common restroom and a sink in the break room. The restroom lavatory faucet is 0.5 gpm or a metering model, and the break room faucet is 1.5 gpm. A sheet that lists one 1.5 gpm faucet for every sink gets a plan comment.

A franchise restaurant with a standard drawing set. The corporate package lists a 0.125 gallon urinal, which meets Mesa's 0.5 gallon limit easily. It also lists a 2.2 gpm sink faucet, which was fine in a city that uses 2.2 gpm for sink faucets but is above Mesa's 1.5 gpm. The same kitchen passes in one city and gets a comment in another.

The edge case: a one-person restroom in a store. Whether the lavatory is private or public is a classification question, and the table does not define either word. The answer flips the limit from 1.5 gpm to 0.5 gpm. Our reading is that a restroom open to customers is public. Confirm with Development Services before you order faucets.

1. 1List every lavatory, sink, shower, urinal and toilet in the project and mark each as public, private or metering.
2. 2Check each cut sheet for its gpm at the table's test pressure, or its gallons per cycle for a urinal, toilet or metering faucet.
3. 3Add the flow rate to the plumbing fixture schedule on the plans. The city's checklist asks plans to show compliance with Table 604.4.
4. 4Submit with the permit application. Mesa Development Services' number printed on its fee schedule is 480-644-4273 if you need to ask how a fixture is classified.
5. 5Keep the cut sheets with the job, so a late fixture substitution can be checked against the table before it is installed.

• Any low flow label satisfies the table. Mesa publishes its own numbers. Check the spec against the table, not the label.
• Sink faucet and lavatory faucet are the same row. The table lists them separately: 1.5 gpm for a sink faucet and 0.5 gpm for a public lavatory.
• The residential table applies to a commercial kitchen. The 1.8 gpm sink faucet limit is in Mesa's residential code, not in the commercial table.
• A neighboring city's drawings carry over. Scottsdale and Buckeye set a 2.2 gpm sink faucet and Mesa sets 1.5 gpm. Buckeye's urinal is 0.125 gallon.

Mesa's own text governs; this page explains it.