Most U.S. municipalities require commercial kitchens to install and maintain grease interceptors. FOG discharge violations carry fines of $1,000-$25,000 per incident, plus potential forced closure. Compliance is straightforward: right-sized interceptor, scheduled pump-outs, and proper documentation.
What Is FOG and Why Does It Matter
Fats, oils, and grease (FOG) cause 47% of all sanitary sewer overflows in the United States, according to EPA estimates. These overflows contaminate waterways, trigger public health emergencies, and result in millions of dollars in municipal cleanup costs annually.
Every commercial kitchen produces FOG. When it enters the sewer system without treatment, it solidifies on pipe walls, restricts flow, and eventually causes blockages. These blockages create sewer overflows that discharge raw sewage into streets, basements, and waterways.
Municipalities respond to this problem with FOG programs that require commercial food facilities to install grease interceptors and maintain them on a documented schedule. Compliance is not optional, and enforcement has increased significantly since 2020.
Who Needs FOG Compliance
Every facility that prepares or serves food commercially must comply with local FOG regulations:
The trigger is not revenue or size. If you have a three-compartment sink, a dishwasher, or a cooking line that produces grease, you need an interceptor and a maintenance plan.
Interceptor Requirements
Grease interceptors (also called grease traps) are plumbing devices that capture FOG before it enters the sewer. Two types exist:
| Feature | Interior Trap | Exterior Interceptor | |---------|--------------|---------------------| | Location | Under sink or in kitchen | Buried outside the building | | Capacity | 20-100 gallons per minute | 500-2,000+ gallon tank | | Cleaning frequency | Weekly to monthly (in-house staff) | Quarterly (professional pump-out) | | Cost to install | $200-$1,500 | $3,000-$15,000 | | Best for | Small kitchens, low volume | Full-service restaurants, high volume |
Most municipalities specify which type is required based on the facility's projected FOG output, which is determined by seating capacity, menu type, and equipment list.
The sizing mistake: 40% of new restaurant grease interceptors are undersized because the installer used the minimum code requirement instead of the actual FOG load. An undersized interceptor fills up faster, overflows sooner, and puts you out of compliance even when you follow the maintenance schedule. Always size for peak load, not minimum code.
Maintenance and Pump-Out Requirements
The universal rule across most jurisdictions: interceptors must be pumped when the FOG layer reaches 25% of the tank's total depth. In practice, this means:
Some municipalities set a fixed pump-out schedule (e.g., every 90 days regardless of FOG level). Others allow extended intervals if you can demonstrate that your interceptor remains below the 25% threshold. Professional grease trap service providers can help you determine the optimal schedule for your specific kitchen.
Penalties for Non-Compliance
FOG violations are taken seriously because sewer overflows create immediate public health risks:
| Violation | Typical Fine | |-----------|-------------| | Missing or expired pump-out documentation | $500 - $2,000 | | Interceptor exceeding 25% FOG depth at inspection | $1,000 - $5,000 | | No interceptor installed (when required) | $5,000 - $15,000 | | FOG discharge causing a sewer overflow | $10,000 - $25,000+ | | Repeated violations within 12 months | Fine doubling + potential facility closure |
Beyond fines, chronic FOG violators risk having their discharge permit revoked, which effectively shuts down the kitchen. Some municipalities publish violation lists publicly, creating reputational damage that outlasts the fine itself.
The cost of compliance (regular pump-outs at $200-$500 per visit) is a fraction of the cost of a single violation. Professional grease trap service providers like GreaseTrapDispatch make scheduling and documentation automatic, removing the compliance burden from busy kitchen managers.
Related reading: Grease Trap Sizing: Matching Interceptor Capacity to Kitchen Output | Pump-Out Procedures: Step-by-Step
