What interval is common for 500-gallon interceptors?

Many full-service restaurants service 500-gallon interceptors every 4 to 8 weeks, adjusted by measured fill rate.

Do hot months affect grease buildup?

Yes. Warmer weather can accelerate odors and instability, making tighter service intervals important during peak months.

How do I set the right service schedule?

Start with baseline intervals, then calibrate using measured FOG depth from your first few services.

Maintenance Schedule Guide

How Often Does a Grease Trap Really Need to Be Cleaned?

The 25% rule, a frequency chart by trap size, and why Los Angeles summers change the equation.

LA Restaurant Services · Field Technician Notes

The 25% rule — what it actually means

Under LACDPH regulations, a grease trap must be serviced before the combined depth of the FOG cap and bottom sludge layer reaches 25% of the trap's total liquid capacity. This is not a recommendation — it is a compliance threshold.

In practical terms: if your trap holds 500 gallons, you must service it before 125 gallons of accumulated FOG and sludge have built up. At that point the separation efficiency drops significantly, and grease begins bypassing the baffle and entering the city sewer.

LACDPH inspectors carry measuring equipment. They can open your trap during a routine inspection and record the depth on the spot. If you are over 25% and have no recent service record, that is a violation — regardless of whether the trap has visibly overflowed.

Frequency by trap size and kitchen type

These intervals are starting points. Your actual frequency depends on menu type, shift volume, and seasonal factors. Use this table to establish a baseline, then adjust after your first two or three services based on how full the trap is at service time. For detailed frequency recommendations by kitchen type and Los Angeles seasonal factors, see our restaurant grease trap frequency guide.

Trap Size	Typical Setup	Service Interval	Common Examples
10–25 gal	Under-sink, high-volume fryer operations	Weekly or bi-weekly	Fast food, taco stands, Korean BBQ
50–100 gal	Under-sink, moderate cooking volume	Every 2–4 weeks	Sandwich shops, cafes with cooking
250–500 gal	Interior or small outdoor interceptor	Every 4–6 weeks	Mid-size restaurants, catering prep
500–750 gal	Standard outdoor interceptor	Every 4–8 weeks	Full-service restaurants
1,000–1,500 gal	Large outdoor interceptor	Every 8–12 weeks	High-volume restaurants, hotel kitchens
2,000+ gal	Industrial or multi-establishment interceptor	Every 3–6 months	Commissaries, institutional kitchens

The LA summer factor

Los Angeles temperatures regularly exceed 95°F from June through September — and valley areas like the San Fernando Valley, where many restaurant corridors are concentrated, can hit 105°F or more. Heat accelerates bacterial activity inside the trap, which breaks down FOG faster and produces hydrogen sulfide gas more aggressively. The result: traps that take six weeks to hit 25% capacity in January may hit the same threshold in four weeks in July.

If your kitchen runs at high volume during summer events, outdoor dining season, or holiday catering peaks, plan to shorten your service interval from May through October. This is one of the most common reasons we see unexpected overflows from kitchens that were otherwise well-managed.

How your menu affects accumulation rate

High FOG accumulation

Deep frying, carnitas, birria, Korean BBQ, Chinese dim sum, fried chicken. These kitchens can fill a 500-gallon trap in half the time compared to a light-fare cafe.

Low FOG accumulation

Salad bars, juice counters, sushi operations with minimal hot cooking. Still require regular service, just at longer intervals than high-fat menus.

High dishwasher throughput

Banquet facilities and high-turnover restaurants run dozens of dishwasher cycles per shift. Hot water from heavy dishwashing accelerates FOG emulsification and trap loading.

Scheduled service vs. emergency — the real cost difference

Emergency grease trap service — triggered by an overflow, a slow drain, or an inspector on-site — typically runs 50% to 100% more than a pre-scheduled visit. That is before factoring in potential overtime rates, same-day dispatch fees, and any compliance penalties assessed.

Beyond the cost, an emergency call usually means your kitchen is already partially offline. A restaurant that loses two hours of service on a Friday night because of a grease trap overflow is losing far more than the cost of the call — and that loss does not show up on the service invoice.

Setting a predictable service calendar based on your trap size and menu is the single most effective way to eliminate that risk. It also simplifies your budget: one fixed line item instead of unpredictable emergency expenses.

Get on a maintenance schedule

Tell us your trap size and volume — we will build a service calendar that keeps you compliant year-round.

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