Every restaurant kitchen produces fats, oils, and grease — FOG, in industry shorthand — and every municipality expects you to keep it out of the sewer system. A neglected grease trap doesn't just risk fines: it backs up into the kitchen during Saturday service, which is a far more expensive way to learn the maintenance schedule.
How a grease trap actually works
Kitchen wastewater enters the trap and slows down; grease, lighter than water, floats to the top while solids settle to the bottom. Cleaner water exits from the middle to the sewer. The system works only while there's room for separation — as grease and solids accumulate, the trap's effective capacity shrinks until FOG passes straight through into your building's drain line, where it congeals into exactly the blockage the trap existed to prevent.
The 25% rule and your real schedule
The widely used standard: pump the trap when combined grease and solids reach 25% of its liquid depth. Past that point separation efficiency collapses. What that means in practice varies enormously — a high-volume fry kitchen may hit 25% in three or four weeks; a light-menu café might take a quarter. The only way to set your real schedule is measurement over a few cycles. Under-scheduling shows up as odors, slow floor drains, and eventually a line backup; over-scheduling just wastes money.
The part everyone forgets: the lines
Even a well-maintained trap passes some FOG, and the drain lines between kitchen fixtures, trap, and building main accumulate a grease lining year over year. This is why restaurants with perfect pumping records still get backups. Scheduled hydro jetting of kitchen lines — commonly every 6–12 months, quarterly for heavy fryers — scours that lining out and is the difference between a maintenance line item and a closed-kitchen emergency. Before-and-after camera footage verifies the work actually happened.
Compliance and records
NJ municipalities and sewer authorities increasingly require documented pumping with manifests, and inspectors ask for them. Keep every service record; a clean paper trail shortens inspections and helps in any dispute about a municipal line issue. Best-practices note for the kitchen: dry-wipe cookware before washing, use sink strainers religiously, and never pour fryer oil into any drain — rendered oil goes to your recycler.
Lumin Drain NJ provides grease-trap-line jetting, camera verification, and maintenance scheduling for restaurants across New Jersey — with after-hours service so the work never touches your operating hours: 929-662-1816.