Colorado Springs Utilities (Colorado Springs, Colo.) says the biggest day of the year for wastewater back-ups is Thanksgiving. That's because people dump turkey fat, oil and grease down the drain instead of throwing it away in the garbage. Your home's wastewater line is about 4 to 6 in. in diameter and can quickly clog up. Spokesman Dave Grossman said, "As the grease goes down into their service line, it will start to solidify or harden, even before it gets out to the main line. And over time, that fat, oil and grease can start to build up and clog drains. And when that happens, it can cause a wastewater back up into your home."
They recommend to dump the turkey fat, oil and grease into a can, let it cool and then throw it away. Then remove the extra droppings in your pan with a paper towel and toss that. Another tip is to minimize the use of your garbage disposal. And scrape those plates right into the garbage can.
Source: Colorado Springs Utilities/KOAA News