Services

Grease Traps

A grease interceptor removes fats, oils, and grease (FOGS) that coat city sewer lines and cause sewer overflows. If an overflow occurs, you may be responsible for clean-up costs and property damage.

How does a large outside grease interceptor (trap) work?

A standard grease interceptor (trap) is large capacity underground vault generally with two compartments (chambers) separated by a baffle accessed by two manhole lids. The purpose of a grease trap is to prevent grease and food solids (FOGS) from entering the sanitary sewer system where it can cause expensive clogs.

It accomplishes this by capturing all of the waste deposited in the drains, triple sinks and dishwasher in the grease trap. Wastewater enters the interceptor unit after leaving the kitchen. As the waste cools the grease floats to the top and food solids settle to the bottom of the first chamber of the unit (see diagram). Water flows into the second chamber where more solids and grease separate out. The remaining water then flows out of the interceptor unit and into the city sewer lines.

It should be noted that a functioning grease trap should always maintain a full liquid level. This does not indicate that the trap is full of grease. A functioning grease trap should be filled to the normal liquid level with a combination of water, grease and food solids.

How does an inside grease trap work?

A grease trap is a small reservoir or steel box either in the floor or near the grease producing area, usually near the triple sink. They range in size from 15-50 gallon, occasionally up to 300 gallons.

The grease trap is designed to remove solids and greases from wastewater. As water and grease enter the grease trap the velocity of the water is reduced, thus allowing the grease, which is lighter than water to cool and float to the surface and solids to settle to the bottom of the trap. The piping configuration allows the water to exit below the grease level thus providing a space for the grease to collect.

Grease traps are effective means of grease removal if the trap is routinely pumped. If the grease accumulates above the maximum grease level, the grease will have no place to collect and will be carried off with the water into the city sewer.