Grease Trap Requirements
Louisville, KY

FOG Compliance in Louisville, KY

Food service establishments in Louisville operate under a combination of federal EPA pretreatment standards, Kentucky 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 1,741 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 Louisville, the rule is: Every 90 days minimum. This aligns with the 90-day US median enforced by most major cities. The city follows the International Plumbing Code (IPC) for trap sizing and installation. Under Section 1003.3.4, which sizes traps by drainage fixture unit counts, grease interceptors installed in Louisville must meet minimum capacity thresholds based on the fixtures connected to them — 3-compartment sinks, dishwashers, pre-rinse stations, wok stoves, and floor drains on the cook line. The local minimum trap size is: 750 gallons minimum for exterior gravity grease interceptors; hydromechanical interceptors sized per fixture drainage load (minimum 20 GPM).

Louisville requires a dedicated FOG permit for any food service establishment generating fats, oils, and grease. The annual permit fee is No separate annual FOG permit fee; MSD wastewater discharge permit required. The permit is separate from, and in addition to, the plumbing permit required at installation. Violations carry maximum penalties of $10,000 per violation per day; MSD may also assess cost recovery for SSO cleanups , 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.

Louisville 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. Annual inspections of FSEs by MSD; higher-risk facilities inspected more frequently. 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 Louisville/Jefferson County Metropolitan Sewer District (MSD), 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.