How much FOG and food debris a grease trap and interceptor hold aren't the only differences. Grease traps are smaller devices with a straightforward design intended to be installed under a sink. In contrast, grease interceptors are complex, with a system that redirects grease to an underground storage tank, typically housed outside.
The installation process for a grease trap is much easier due to its simplistic design. It can usually be installed within a day. Meanwhile, installing a grease interceptor can take up to a week. It requires professional project management to excavate a site for the tank, set up any additional plumbing needed to support the system, and install the device.