A grease interceptor, also known as a grease trap, is a passive plumbing control device designed to reduce the amount of fats, oils and greases that enter the sanitary sewer collection system.
Grease interceptors work by providing a retention chamber that is designed to slow the drainage flow to permit grease to float, solids to settle and the then “clean” water to exit to the drain/sewer system.
Building codes require the installation of grease interceptors wherever fats, oils and greases (FOG) could be discharged into the sewer system. Sewer-use bylaws limit the amount of FOG and suspended solids that are permitted to be discharged to the sewer system.
In order for grease interceptors to work properly they must be:
- properly sized
- properly installed
- properly cleaned, and
- properly maintained
Grease interceptors must be serviced on a regular basis to ensure efficient operation. Many jurisdictions have by-laws requiring grease interceptors to be serviced on a regular basis. In addition to removing waste accumulations and restoring full treatment capacity to the interceptor, a visual inspection of the interceptor for corrosion, damage, and missing components must be performed regularly. Unlike a conventional waste collection receptacle, the user has no way of knowing when a grease interceptor has reached its waste retention capacity without inspecting it as it is being emptied. An “over-full” interceptor will discharge waste to the sewer, violating sewer use bylaws and eventually causing serious drain problems.