The terms "grease interceptor" and "grease trap" are used interchangeably by the Town of Cary.

A grease interceptor is a chamber for fats, oils, and grease-laden wastewater to pass through and allow free or emulsified oil to float to the top for retention as the remainder passes through. For fats, oils and grease to float to the top, non-turbulent, static conditions are necessary. Interceptors are designed and sized based on anticipated flow rates and load of fats, oils and grease.

Food preparation and serving establishments deemed to need grease interceptors must adhere to the procedures and requirements below:

Sizing and Design Requirements

• General Pre-treatment Program Plumbing Requirements
• Grease Interceptor Installation Planning
• Grease Interceptor Installation Permit Acquisition Process
• Grease Interceptor Sizing Spreadsheet
• Grease Interceptor Detail with Sample Vault
• Hydraulic Jump Sample Vault Detail
• Inlet and Outlet Sanitary Tee Diagrams
• Community Grease Interceptors
• Town of Cary Inspections and Permits Department
• Trash Compactor Pad Drain Detail

For an electronic copy of the grease interceptor sizing spreadsheet or for design questions, please contact:

Donald Johnson - Utility Pretreatment Program Supervisor
Utilities Department
400 James Jackson Ave.
(919) 319-4564
Don.Johnson@carync.gov

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