Do you need plan review to replace a grease interceptor in Phoenix?

The FOG Best Management Practices Manual (June 2024) says: "Per plumbing code all grease interceptors installed and replaced in the City of Phoenix must go through plan review." It gives the reason too. Review makes sure the interceptor "is sized correctly, approved for use in the City of Phoenix, and that all grease bearing fixtures are plumbed to the interceptor." It then splits the process in two:

• Over the counter: "Like for like replacements of hydromechanical interceptors can be submitted over the counter." Appendix B adds that the job must be small and involve plumbing only.
• Electronic plan review: any plans with major plumbing changes, "including installation of a new grease interceptor," cannot go over the counter.

The 2024 plumbing code amendment behind this gives the Director of Water Services approval authority over each interceptor's size, type and location.

• Hydromechanical interceptor: the grease trap, usually small and indoors.
• Like for like: the manual does not define it. Read it as the same kind of device serving the same fixtures with no piping changes. That is a reading, so ask the reviewer when the new unit differs in size.
• Grease-bearing fixtures: floor sinks, floor drains, mop sinks, prep and pot sinks, dishwashers, garbage disposals and similar fixtures in the kitchen prep or wash area. Hand wash sinks do not count.
• Isometric drawing: a single-line pipe drawing that shows pipe sizes and venting.

Food service owners and their contractors replacing or adding an interceptor in the City of Phoenix. It does not cover routine pumping and cleaning, which needs no review. Auto shops with oil separators are outside the manual's food service process.

• Cracked trap under the pot sink. The owner buys the same approved model, connects it to the same lines, and takes a plumbing floor plan to the counter. The city reviews it over the counter.
• Restaurant moves its prep sink during a remodel. A fixture is rerouted, so the drawings must include an isometric with pipe size and venting.
• Dishwasher added to a trap-only kitchen. The answer flips. The dishwasher forces a gravity interceptor, which is a new installation and needs electronic plan review.
• Inspection finds the interceptor rotted out. The inspector's requirement is the reason for the job, so the owner brings a copy of the Commercial Inspection Report to the review.

1. 1Decide whether the job is like for like. If the type, size or piping changes, plan on drawings.
2. 2Pick the device from the city's approved interceptor list in Appendix A of the manual. Trap models must be PDI certified or UPC/IAPMO listed. Gravity units must be 500 gallons or more with two compartments and two manways.
3. 3Prepare the submittal: business name, full address with suite number, every existing grease-bearing fixture, a north arrow or orientation mark, and the interceptor's manufacturer and model number. Drawings must be legible or the review is denied.
4. 4Call 602-495-0278 at least 24 hours ahead to book an Environmental Services inspector for their part of the review. Then submit through Planning and Development. Commercial plan review moved into the SHAPE PHX portal April 27, 2026, and the manual's Appendix B still describes older channels and a pandemic-era appointment note, so call 602-262-7811 to confirm which route your job takes.
5. 5Have the certificate of occupancy in order, because the manual says one is required for all these plan reviews, then schedule the inspection when the unit is set.

• "A like-for-like swap is just maintenance." The manual sends every replacement through plan review. The counter is only the shorter lane.
• "A hand sketch is fine." The city says illegible drawings are denied.
• "Any interceptor replacement can go over the counter." Only like-for-like replacement of hydromechanical units is named there. New interceptors go electronic.
• "The pumper's invoice covers it." Pumping records prove maintenance. They do not replace plan review for a new device.