How to Tell If Your Grease Trap Was Actually Serviced

Measure FOG depth before starting

A thorough tech measures and records the FOG layer depth before pumping. This tells you how full the trap was and is the baseline for your compliance record. If no measurement was taken, there is no way to prove the service was timely under the 25% rule.

Pump all three layers — not just the top

The whole point of the service is to remove the FOG cap, the middle effluent, and the sludge layer on the bottom. A tech who only skims the surface and calls it done has left the worst material behind. Total volume extracted should be consistent with the trap's size.

Scrape and rinse baffle walls

The baffle (the divider inside the trap) accumulates a hard crust of solidified grease over time. If it is not scraped during service, the buildup eventually restricts flow and shortens the interval before your next overflow. A quick rinse alone does not count.

Inspect baffles and lid gasket

Damaged baffles allow FOG to pass straight through to the sewer without separating — defeating the entire purpose of the trap. A cracked lid gasket can let odors escape into your kitchen. Both should be visually checked and noted in the service report.

Record gallons extracted

The waste manifest requires documentation of the volume pumped. This is not optional. It tells you whether the service was consistent with your trap size and usage, and it is what LACDPH will ask for during an inspection.

Issue the waste manifest before leaving

The manifest is a legal document certifying where your FOG waste went after it left your property. It must reference a licensed disposal or rendering facility. You should receive this before the truck drives away — not days later by email.

In and out in under 10 minutes for a large trap

A 500+ gallon interceptor cannot be fully pumped, scraped, and inspected in 10 minutes. If the truck arrived, connected a hose, and left quickly, it is likely they vacuumed only the liquid and skipped the solids.

No manifest provided at the time of service

A legitimate licensed waste hauler always has the manifest form on the truck. If they say they will send it later — and then do not — you are left with no compliance record. That is your liability, not theirs.

Cannot tell you where the waste went

If a technician cannot name the disposal or rendering facility, that is a serious red flag. FOG waste must be transported to a licensed facility. Illegal dumping is a felony in California and can be traced back to the generator (you).

No measurement before or after

Professional service includes measuring the FOG layer depth before extraction so you know the trap was cleaned at the right time — not too early, not dangerously late. Skipping this step means the contractor cannot prove the service met the 25% rule.

Unusually low price with no documentation

If someone quotes you significantly below market with no mention of manifests or compliance paperwork, they are likely cutting corners on disposal. In California, licensed manifest hauling has a cost floor. Prices that seem too good usually mean something is being skipped.