Grease Traps


Grease traps are passive devices required by municipalities to stop grease, fat, oil, wax or debris from entering the city’s sanitary sewer system. Such materials cause blockages in the system, which cause backups and overflows. Traps are designed to separate greasy materials from wastewater so that they can be removed before they enter the sewer system. All restaurants, caterers, school cafeterias and other commercial cooking facilities must avoid discharging grease into the municipal sewer system. Grease traps must receive wastewater from all contributory sources, such as pot sinks, dishwashers, floor drains and mat washing area drains before draining to the sanitary sewer.


How often should you service a grease trap? Due to its small size (5-150 gallons), grease traps are typically cleaned between 4-8 weeks on the average. When a grease trap is 750, 1000, 1500 or more gallons, this means that in normal working condition it must have that constant amount at all times; unless there is a blockage. Once a trap arrives at its maximum capacity, for every liquid that it takes in, it releases at the same amount out to the city sewer lines. Therefore, a grease trap should always be filled whether its’ with only water or with a combination of grease, water and solids. Grease and Solid waste entering the grease interceptor will mainly come from the kitchen; no sanitary waste should ever enter this system unless there is a plumbing problem. Grease traps are efficient when the grease and solid content level is 30% or below. Once it goes over that level it starts to release higher amounts of grease and solids to the main or city sewer. Hence, when running efficiently grease traps can trap up to 80-85% of grease and solids. Therefore, there are still a large percentile of grease and solids that escape out of the trap. Since there are still a percentage of grease being released, in order to maintain the lines from blockage it is highly suggested for the grease lines to be cleaned every 6-12 months. Failing to properly maintain the lines can lead to grease trap overflow or line blockage. Grease traps are not supposed to go over 30% of combined solid and grease count. Failing to properly pump or clean a grease trap in a timely manner can lead to main line blockage causing the device to overflow and/or sinks to not drain.


Grease traps can have one or more chambers and manholes. When pumping the trap we remove all the lids and pump from the top until it is completely empty. Please note that in order to properly service a grease trap, all content must be removed from top to bottom. Since grease traps contains grease and water, the servicer must pump out the grease and water in order to reach the solids in the bottom. Keep in mind that the fact that solids are heavier than both grease and water, it settles in the bottom and over time it can solidify and be very costly to remove.