GREASE BLOB FAQ

Why is it important to not put about cooking oil and grease going down the drain?
Pouring cooking oil or grease down the drain sticks to the insides of the wastewater pipes, and can cause sewage back-ups, overflows and very costly repairs. Sewage overflows may cause a threat to public health and the environment; plus the City of Austin is under an Administrative Order from the United States Environmental Protection Agency (EPA) to address persistent problems with sanitary sewer overflows.

Why are cooking oils and grease a problem for wastewater pipes?
Fat, cooking oil and grease are only partially soluble in water and are not compatible with wastewater piping. If poured down the drain, these substances thicken, coagulate, and stick to the drainage piping, forming gooey-gross deposits that grow each time more greasy waste enters the pipes. Whether these deposits form in the homeowner's wastewater pipes or the city sanitary sewer lines, the end result is a clogged pipe and costly repairs. These blockages may also be accompanied by foul odors, significant property damage, and even environmental harm.

What is the difference between oil and grease?
The terms are often used interchangeably, but they are very different substances. Oil, such as vegetable or olive oil, is liquid and never turns into a solid. Grease is the solid residue leftover in the cooled pan after frying meat, such as bacon.

Why are oils that do not solidify a problem?
Many oils actually do solidify at lower temperatures and therefore clog the drainage system. Even if oils don't solidify they often bind to other forms of fats and grease.

What are the common mistakes people make when disposing of cooking oils and grease?
When many people are finished cooking, they tend to dump leftover cooking oil, grease, and/or food scraps down the sink and turn on the garbage disposal. Another common mistake is rinsing dishes in the sink with hot water to remove the grease residue left on plates. Hot water may serve only to push the potential clog further down the pipe, often meaning that the eventual blockage may be even more costly to repair.

How should I dispose of cooking oil and grease?

  • Collect small quantities of cooking oil or grease in a coffee can, empty milk carton, or similar container (preferably with a lid so it doesn’t pour out); optionally, it can be mixed with kitty litter, and doubled bagged; chill grease in the fridge if you need to get it to harden up.
  • Toss this item in your trash cart, or even better, recycle it at Austin’s Resource Recovery’s Recycle & Reuse Drop-off Center
  • Put greasy food scraps in the trash…unfortunately, very greasy and oily food cannot be composted.
  • Try not to put greasy food scraps in the garbage disposal.
  • Use a paper towel to wipe grease from pots, pans, plates, and utensils prior to washing.
  • Use a sink strainer to catch food particles.

What about restaurants or large quantities of cooking oil and grease?
For restaurants, or large quantities of grease, learn about Austin Water’s Grease Trap Program.