Many times, grease is wasted into the plumbing system, usually through the kitchen sink. Grease sticks to the insides of sewer pipes (both on your property and in the streets). Over time, the grease can build up and block the entire pipe.
Here are some quick tips for appropriate FOG disposal:
Garbage disposals do not keep grease out of the plumbing system.
Never pour grease down sinks, drains, or into toilets.
Scrape grease and food scraps from plates, pots, pans, utensils, and cooking surfaces into the REGULAR TRASH for disposal.