Grease Control (FOG) — Sewer Discharge Compliance Application & Grease Interceptor Approval: Nashville restaurant guide
Metro Water Services — Environmental Compliance
What it is
Metro Water classifies your restaurant and sets the size of the grease trap or interceptor you must install. Full-service restaurants need at least a 1,500-gallon interceptor.
When a restaurant needs it
All new food service establishments, upgrades and ownership changes must submit before installing grease control equipment.
How to apply
Your engineer, architect or contractor completes the Sewer Discharge Compliance Application, listing cooking equipment, fixtures and drain sizes, and emails it to MWS Environmental Compliance.
Documents you’ll need
- Sewer Discharge Compliance Application
- List of all cooking and food prep equipment
- Fixture counts and drain sizes
- Menu type / FSE classification
- Grease control equipment dimensions and location plan
Good to know
Interceptors must be pumped when FOG plus solids reach 25% of liquid depth, and at least every 90 days (180 with digital monitoring). Traps need cleaning at least every 30 days. Keep records for 3 years.
Official source
Metro Water — Grease management · MWS FOG Management Policy (PDF)
Answer a few questions about your space and get every permit in order, with a timeline, a cost range, walkthroughs, and every application filled in for you to sign with Open.
Last reviewed 2026-10-06. Guidance only, not legal advice.