Grease Trap Requirements
Chicago, IL

FOG Compliance in Chicago, IL

Food service establishments in Chicago operate under a combination of federal EPA pretreatment standards, Illinois 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 12,246 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 Chicago, the rule is: Every 90 days minimum or when 25% full (whichever comes first). This aligns with the 90-day US median enforced by most major cities.

Chicago requires a dedicated FOG permit for any food service establishment generating fats, oils, and grease. The annual permit fee is Sewer discharge permit required; FOG registration included with building/sewer permits. Permit fees vary based on discharge volume. The permit is separate from, and in addition to, the plumbing permit required at installation. Violations carry maximum penalties of $1,000 per day per violation under Chicago Municipal Code; repeat offenders face escalating fines , 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.

Chicago 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. Chicago Department of Water Management conducts inspections; frequency based on compliance history, typically annually for FSEs. 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 Chicago Department of Water Management, 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.