Commercial Sewer Cleanout Requirements by Valley City

These rules cover the private drain and sewer piping a business owns: from the fixtures, through the building drain, out to where the building sewer meets the public main. They matter most when that piping is new, replaced, rerouted or added to, and when a tenant improvement moves fixtures or covers existing cleanouts.

• Building drain: the lowest piping inside the building that collects waste and carries it to the building sewer just outside the wall.
• Building sewer: the private pipe from the end of the building drain to the public sewer or a private disposal system.
• Developed length: distance measured along the centerline of the pipe and fittings, not in a straight line across the lot.
• Two-way cleanout: a fitting that opens both upstream and downstream, so a cable or jetter can go either way.
• Hydromechanical grease interceptor: a compact, engineered interceptor that uses flow control and baffles to separate grease, often under a sink or in a small pit. A gravity grease interceptor is a large in-ground tank.
• Manhole: a large access structure that replaces cleanouts on sewers 8 inches and larger.

Phoenix lets plumbing plans follow either the 2024 International Plumbing Code (IPC) or the 2024 Uniform Plumbing Code (UPC). Mesa, Chandler, Glendale, Surprise and Tempe are on the 2024 IPC. Scottsdale and Queen Creek use the 2021 edition, and Gilbert and unincorporated Maricopa County are on 2018 editions. The numbers below come from the 2024 IPC, Section 708. The UPC counts turns differently; our cleanout code FAQ covers that version.

Inside the building. Horizontal drains need cleanouts "at intervals of not more than 100 feet." A building drain may use manholes instead, spaced up to 400 feet apart.

Building sewers under 8 inches. A cleanout at least every 100 feet, measured along the pipe.

Building sewers 8 inches and larger. The code switches to manholes: "a manhole located not more than 200 feet" from the building drain junction "and at intervals of not more than 400 feet." This catches large retail centers, hospitals and warehouses with a long private main.

The junction. A cleanout "at the junction or within 10 feet" upstream of where the building drain becomes the building sewer. Removing a water closet does not count as access.

Turns. A change of direction over 45 degrees needs a cleanout, but one cleanout covers every such turn within 40 feet of developed length.

Size, clearance and access. A cleanout matches the pipe size but never needs to exceed 4 inches. It needs 18 inches of clearance in front for 6-inch and smaller pipe and 36 inches for 8-inch and larger. It cannot sit in a plenum, wall, floor/ceiling assembly or low crawl space. Below-grade cleanouts are extended up to grade, assemblies to ASME A112.36.2M go where vehicles drive, and indoor manholes need gas-tight covers that take tools to open.

Phoenix and interceptors. The IPC amendment requires a two-way cleanout "on the discharge side of all hydromechanical grease interceptors." The UPC amendment goes further, covering "all separators, interceptors, (clarifiers) and hydromechanical grease interceptors," and requires gravity interceptors to have "a vented two-way cleanout on the discharge side." Phoenix's stated purpose is "to provide an entry point to clean the line downstream of the device and back to the device."

Mesa and city crews. Owners maintain the building connection to the public sewer. The exception is a damaged or broken section "located off-property in a street or alley," which the city repairs. When the city checks a blockage, its form says "The Homeowner has to provide access to the service line, by clean out or exposed service only."

Chandler and records. Chandler "does not keep or maintain records detailing location information for a sewer cleanout on private property." On an older commercial site with no as-builts, a camera and locator are often the way to find the line.

Cave Creek and Fountain Hills inspections. Cave Creek's under-slab checklist wants a tracer wire from the junction cleanout "run with the piping to the sewer tap." In Fountain Hills, the builder calls the sanitary district for a sticker on the cleanout before fill goes in.

Avondale and Litchfield Park. Avondale's engineering permit fees list sewer cleanouts at $50.00 each. Litchfield Park requires a sewer cleanout within 50 feet of the pumping equipment on any new pool.

Same restaurant, two designs. A Phoenix restaurant replaces a failed hydromechanical interceptor. Under either code path it needs a two-way cleanout on the outlet. Its neighbor installs a new 1,000-gallon gravity interceptor. If the plans follow the UPC, Phoenix's amendment requires a vented two-way cleanout on the outlet. If they follow the IPC, the Phoenix amendment we reviewed names only hydromechanical interceptors, so the outlet line follows the general Section 708 rules.

Same warehouse, two pipe sizes. A Mesa warehouse runs a 6-inch private sewer 300 feet to the street: cleanouts at no more than 100-foot intervals. If the engineer upsizes to 8 inches for future tenants, the answer flips to manholes, the first within 200 feet of the junction.

A repaved lot. A Tempe retail center repaves its parking lot. Cleanouts in the drive aisle come up to the new grade in traffic-rated assemblies, not plastic caps paved over.

• "The city knows where my cleanout is." Chandler states that it keeps no such records for private property. Ask your own city before you count on it.
• "A cleanout is a cleanout." Size and clearance scale with the pipe, and an 8-inch sewer needs manholes outside the building.
• "I can tie the new sink into that cleanout." The IPC prohibits using a threaded cleanout opening to add a fixture unless another cleanout of equal size is installed.

1. 1In Phoenix, file through the Planning and Development Department. The FOG manual says "all grease interceptors installed and replaced in the City of Phoenix must go through plan review." Like-for-like interceptor replacements can be reviewed over the counter by appointment. A new interceptor or major plumbing change goes through electronic plan review. Show the two-way cleanout on the drawings.
2. 2In other cities, pull the plumbing permit before work starts. The permit holder schedules the inspection that covers the building sewer before it is covered. Cave Creek checks cleanouts, slope, depth and tracer wire at its under-slab inspection, and Fountain Hills needs the district's cleanout sticker first.
3. 3Count the cleanouts against the run. Walk the building sewer from the building to the tap. Look for one at the junction, one at least every 100 feet, and one at each sharp turn.
4. 4Check what sits on top of them. Pavers, planters, racks and new millwork are the usual reasons a required cleanout becomes unusable.
5. 5Cap them. The Fountain Hills Sanitary District says cleanouts "should have a removable cap installed, to contain odors." A missing or cracked cap also lets debris in.

HQ Plumbing and Air installs and repairs cleanouts on commercial building sewers, and handles line clearing, camera inspection, and grease interceptor inspection and repair.