The phrase “25% rule” is common in grease-trap discussions, but it is often oversimplified. For Columbus facilities, the useful question is what the City’s current BMP guidance actually says and how that guidance relates to a facility-specific cleaning schedule.
The Grease Trap 25% Rule in Columbus, OH
This page explains the Columbus guidance for service planning. It does not replace the facility’s BMP, approved design, equipment instructions or directions from the authority with jurisdiction.
What the 25% guideline does—and does not—tell you
It tracks accumulation
The concept focuses on retained grease and solids taking up part of the interceptor’s effective capacity.
It is not a fixed number of days
Two kitchens can reach similar accumulation at very different rates because their menus, meal counts and equipment differ.
Records matter
Cleaning logs make it possible to compare actual removal from visit to visit instead of estimating from memory.
Design intervals also matter
Columbus code includes designed service intervals for approved interceptor systems; that is a separate requirement from generic online advice.
Kitchen changes matter
New equipment, higher capacity or menu changes can increase grease production and make an old schedule a poor fit.
Condition still matters
A facility also needs to respond to backups, overflow, damaged components and other conditions that are not captured by one percentage.
What Columbus says about 25% capacity
The City’s FOG BMP instructions recommend maintenance when a grease interceptor nears, but does not exceed, 25% capacity. That wording matters. It is a maintenance recommendation tied to accumulation—not a statement that every food-service operation must be pumped on the same 30-, 60- or 90-day schedule.
The current BMP packet is published through the City’s Sewer Forms page. Facilities should use the current City materials rather than relying on a copied rule from an old service-company page.
25% guidance and designed service intervals are different
Accumulation guidance
The 25% concept helps a facility think about how much grease and solids are being retained before the interceptor loses too much effective capacity. Cleaning records provide evidence of what was actually removed.
Designed service interval
Columbus City Code 1145.04 requires a designed service interval to be included with interceptor design calculations and sets maximum designed intervals for certain construction materials. See the current code excerpt for the actual language.
Use the cleaning log to refine the schedule
A practical review looks at the last several services: the interval between visits, the grease and solids removed, the reported equipment condition and any change in kitchen operations. If accumulation is consistently low, ask whether the current schedule still reflects the approved facility plan and equipment guidance. If accumulation is consistently high, review the interval and operating practices before waiting for a backup.
The Columbus cleaning-log guide explains which service details are useful to retain.
Related resources
The Grease Trap 25% Rule in Columbus, OH FAQs
Yes. The City’s current FOG BMP instructions recommend maintenance when a grease interceptor nears, but does not exceed, 25% capacity. Use the current City packet for the source wording.
No. The percentage guidance and a calendar interval are different concepts. Columbus code also includes designed service-interval requirements for approved interceptor systems.
No. The current City cleaning-practices rule specifically distinguishes the amount of grease and solids removed from water. The facility cleaning record should not treat total liquid volume as the same measurement.
Review the schedule, kitchen changes, operating practices and equipment with the appropriate provider or professional rather than waiting for the old calendar date.
Use the 25% guideline as evidence, not a slogan
Compare the facility plan, approved service interval and real cleaning records. If the current timing no longer fits actual accumulation, document the issue and discuss the next interval with the appropriate provider or professional.