Most restaurants and food facilities have a grease trap or grease interceptor. They can be located inside or outside. Inside tanks range from 20 gal-250 gal. As outside tanks range from 500 gal-10,000 gal. The way it works is grease is lighter than water so it tends to float and the system will cause it to suspend in the holding tank As te water is released to the sewer line. The more grease the better, it means your system is function properly. If there isn’t a large amount of grease after your 3 month service that can indicate a problem. Therefor can mean grease is escaping to sewer system. We are  certified pumpers and have our own trucks and are in service anytime.