Grease Trap Requirements
Nashville, TN

FOG Compliance in Nashville, TN

Food service establishments in Nashville operate under a combination of federal EPA pretreatment standards, Tennessee state plumbing code, and city-level FOG ordinances. Together these rules determine how grease traps must be sized, how often they must be pumped, and what happens when a restaurant falls out of compliance. The city has approximately 2,262 food service establishments — every one of them subject to the rules summarized below.

Pumping frequency is the compliance rule restaurant owners interact with most often. In Nashville, the rule is: At minimum every 90 days. This aligns with the 90-day US median enforced by most major cities.

Nashville requires a dedicated FOG permit for any food service establishment generating fats, oils, and grease. The annual permit fee is FOG permit/registration required; fee schedule set by Metro Water Services (typically nominal or included in sewer service). The permit is separate from, and in addition to, the plumbing permit required at installation. Violations carry maximum penalties of $10,000 per day per violation under Metro Nashville Code; $50,000 maximum per violation under Tennessee Water Quality Control Act , in line with typical US municipal penalties. Fines typically escalate with repeat violations, and severe discharges that cause sanitary sewer overflows can trigger federal Clean Water Act penalties layered on top of local fines.

Nashville enforces the 25 percent rule: grease traps must be pumped before the combined FOG and settled solids reach 25 percent of the trap's total liquid depth. Inspectors measure the depth with a sludge judge or dipstick, typically at surprise visits. Exceeding the threshold at inspection triggers a notice of violation and mandatory emergency pump-out, regardless of the scheduled pumping cycle. Annually; Metro Water Services inspects on routine and complaint-driven basis. Establishments must maintain pumping logs, hauler manifests, and inspection reports on-site — missing records is itself a violation in most enforcement actions. Enforcement authority rests with the Metro Water Services (MWS), Industrial Pretreatment / FOG Program, which handles permit issuance, inspections, and hauler licensing.

For a deeper explanation of the rules this city enforces, read our guides on how grease traps work and the 25/50 pumping rule.