By the dispatch desk · 2026-04-22 · Read time ≈ 7 min
Most Houston operators we walk through for the first time know that their grease interceptor needs to be pumped quarterly. Most do not know that the 90-day rule has a waiver clause. The waiver clause is the part of Houston Code §47-512(b) that an operator with a low-volume kitchen — and an honest grease-load reading — can use to move to a 180-day pump cycle. We have helped clients file twelve of them in the last two years; they have all been approved.
The text of the rule
The relevant clause, paraphrased: every grease interceptor located within the incorporated city limits of Houston shall be fully evacuated at least once every ninety days unless an approved Notice of Waiver is on file with the Houston Health Department. The waiver requires a quarterly measurement, attested by a registered transporter or a permitted FOG inspector, demonstrating that the interceptor's combined floating materials, sediment, oils, and greases are below 25% of the wetted height of the device at the 90-day mark.
Three things in that sentence matter. One: "wetted height," not "total height" — the measurement is from the bottom of the device to the invert of the outlet pipe. Two: the 25% threshold is combined, not per-component — a kitchen with a lot of sediment but very little floating grease is still over the threshold if the combined sum is over. Three: the attestation can be by a registered transporter, which is the contractor doing the pump-out, OR by a permitted FOG inspector, which is a small additional Houston regulatory category most operators don't know exists.
Who actually qualifies
The clear cases: breakfast-only cafés, single-shift operations under 50 covers a day, kitchens with very low grease-load menus (sushi, salad, vegetarian). The harder cases: dinner-only operations that look low-volume on the books but produce a high grease load per cover. The unambiguous-no cases: any kitchen with solid-fuel cooking, any kitchen running 24-hour operations, any kitchen with a fryer station running more than three hours a day.
What goes into the application
Three pages. The first page identifies the operator, the kitchen address, the interceptor capacity, and the cooking-equipment inventory. The second page is the measurement attestation, signed and dated by the registered transporter or FOG inspector. The third page is a recap of the past four quarterly pump-out manifests, demonstrating the historical pattern. The application goes to the Houston Permitting Center's Special Waste Program (832-393-5740 for direct contact). Approval typically takes three to four weeks.
What the waiver doesn't do
It does not eliminate the obligation to measure. A waivered operator still has to measure quarterly; the change is to pump only every 180 days. If the measurement at the 90-day mark exceeds 25%, the waiver is suspended for that quarter and the standard pump cycle resumes.
It also does not waive any other Houston FOG obligation. The grease-trap permit (annual, separate fee), the food-establishment permit, and the discharge limits all remain in force. The waiver is narrow.
Why most operators don't file
Two reasons, in our experience. The application looks bureaucratic enough that most small operators assume the savings won't justify the time, and most pumping contractors don't recommend it because they bill by the pump-out and the waiver moves their work from quarterly to semiannual. We have run the math for our clients more times than we can count. For a typical small Houston kitchen with a 1,000-gallon interceptor, the waiver saves around $520 a year — not life-changing money, but enough to be worth a Wednesday afternoon.
The honest test
If your last four pump-out manifests show combined grease, oil, and sediment well below 25% at every quarter — meaning your interceptor is being pumped earlier than it needs to be — the waiver is worth filing. If even one of the four shows combined contents above 25%, the waiver isn't going to work. Either way, the math is what it is.
One closing note
The 25% threshold is conservative compared to the EPA's recommended FOG management threshold, which most jurisdictions set at 25–30% but a number set at 35%. Houston is at the conservative end of the national range, which we read as the city erring on the side of public-sewer protection rather than operator convenience. We agree with the call.