The Boise sewer system is a collection of more than 700 miles of pipes that weave underneath the City.The Boise Public Works Department maintains the intricate sewer system and much more. Along with regular system maintenance, Public Works makes major repairs and is in charge of designing the system. Since 1985, Public Works has also regulated industrial and commercial wastewater discharges into the sewer system through its EPA-approved Pretreatment program. The Pretreatment Program also administers the Residential Fats, Oils, and Grease (FOG) program. In addition, Public Works also sets the sewer rates for residential and commercial users and administers sewer billing.