Yellow grease is used cooking oil from fryers, collected in a bin and recycled. Brown grease is what a pumper removes from a grease trap or interceptor. Fryer oil never belongs in the drain or the trap. Phoenix and Chandler tell restaurants to recycle it or dispose of it dry.
Yellow grease
Yellow grease is used cooking oil, the fryer oil you change out. New York City's business guide describes it as oil that is often picked up for free because it can be recycled. It stays in the fryer, the storage container and the collection bin. It has no reason to touch a drain.
Phoenix's FOG manual says to recycle waste cooking oil, and notes that some collection companies pay for it or discount interceptor pumping in exchange. The city's inspector also looks at the outdoor tallow bin and trash area for oil on the ground, which can wash into the storm drain.
Brown grease
Brown grease is what comes out of the trap or interceptor. NYC describes it as grease from traps that is more solid than fryer oil. It is a mix of grease, food solids and wastewater, and a licensed hauler takes it away. That is why Phoenix says the pumper must remove the whole mat, liquids and sludge and take them to a licensed disposal facility.
Can fryer oil go in the grease trap?
No. Phoenix's kitchen practices say to scrape or dry-wipe grease from pots, pans and fryers into the trash, and to recycle waste oil. Chandler's rules limit fats, oils and grease of vegetable origin in the wastewater to 100 mg/L, emulsified or not. A trap is there to catch what slips through, not to take a fryer's worth of oil. Dumping it in fills the device quickly and pushes you toward a violation.
What to do
- 1Keep a lidded collection container at the fryer and a recycler on contract.
- 2Use dry cleanup for spills before mopping.
- 3Leave the trap for wash water, not for oil.
For the rest of the list, see what can go into a restaurant grease trap. Enzyme products are not a shortcut either. See enzyme grease treatments in Phoenix.