The problem is frequently caused by dumping grease down the drain. Employees may be sending enormous volumes of food waste down the drain if your business facility has a restaurant or commercial kitchen. Grease and fats, for example, should never be dumped down the drain. People frequently assume that running hot water while pouring oil or fats down the drain constitutes a do-it-yourself main sewage line cleanout. This simply is not true.  Conversely, the hot water warms the grease or fats in the sewage line, causing them to solidify on the pipe when it cools.