Fats, Oils, and Grease (FOG) are a sewer pipe’s worst nightmare. Pouring old or used grease from cooking down a drain is the worst thing to do to a household’s sewer pipes. That’s because grease will eventually turn solid, which can create a blockage in your pipes. If grease buildup occurs, you will need to have your pipes professionally cleaned. That’s why it’s so important that people know that pouring any grease down the drain can cause property damage that you as a homeowner are responsible for.