The Grease Control Program was instituted to address the problems associated with animal fat, oil and grease buildup and clogging of sewer lines. Grease accumulation in the sewer collection system is one of the major causes of sewer blockages and subsequent sanitary sewer overflows. Based on available information, standards were set and procedures put in place for a grease control program.

Grease traps/interceptors are required for all food preparation establishments, which may contribute or cause to contribute, directly or indirectly, any wastewater that contains oil or grease. This includes but is not limited to, restaurants, cafeterias, cafes, fast food outlets, schools, fraternal organizations, churches, hospitals, and daycare centers. Marietta Water's Environmental Compliance personnel currently inspect more than 315 facilities in the City of Marietta. Some of these facilities use what is known as an interior grease trap. The trap prevents excess grease from getting into the sewer system from existing plumbing lines within facilities. Traps are small and are usually installed inside a facility. Generally, they range in size from 20 gallons per minute (gpm) to 50 gpm. Many high-volume or new establishments, use grease interceptors that are larger than the interior traps and are installed underground, outside of a facility. Grease is actually "intercepted" in these concrete tanks before it reaches the City sewer main. Grease interceptors should be accessible by manhole covers. Interceptors and traps cause the flow of water to slow down, allowing the grease to naturally float to the top of the tank for easy removal. In-line interior grease traps may not be allowed, unless otherwise approved by Marietta Water. Grease interceptors are not required for private residences or dwellings.

The grease interceptor design and sizing criteria must adhere to the requirements established by Marietta Water and will be subject to approval. Marietta Water has adopted the sizing criteria developed by the Cobb County Water System. Those grease traps/interceptors not able to achieve compliance with current standards may be subject to modification and/or replacement. Existing sources not connected to grease interceptors or those sources connected to in-line interior grease traps that contribute significant quantities of oil and grease wastes may be required to install an upgraded grease interceptor.

Maintenance of grease traps/interceptors is the sole responsibility of owner or operator. The owner or operator must ensure proper operation to prevent obstruction, interference or damage to the collection system. All grease interceptors must be pumped dry and the contents hauled and disposed of by EPD permitted commercial transporters. The use of bacteria or enzymes is not prohibited; however, may not be used as a substitute for regular pumping of a grease interceptor. Grease interceptor pumping, at a minimum, must be completed every three months, unless determined more or less frequent pumping is required. Marietta Water's Environmental Compliance personnel have implemented an inspection program to ensure compliance.