Grease Trap Requirements
Providence, RI

FOG Compliance in Providence, RI

Food service establishments in Providence operate under a combination of federal EPA pretreatment standards, Rhode Island 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 1,753 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 Providence, the rule is: Annual minimum by licensed hauler per NBC Wastewater Discharge Permit. This is more lenient than the US median, typical of jurisdictions with lower-volume food service sectors. 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 Providence 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: 500 gallons minimum (in-ground passive interceptor; 4 ft min depth, 24-hour detention).

Providence requires a dedicated FOG permit for any food service establishment generating fats, oils, and grease. The permit is separate from, and in addition to, the plumbing permit required at installation.

Providence 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. NBC conducts ~2,000 inspections/year across ~1,060 permitted companies. 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 Narragansett Bay Commission (NBC) Pretreatment 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.