Grease Trap Requirements for Georgia Plumbing

Grease trap installation and maintenance requirements govern food service establishments, commercial kitchens, and industrial facilities operating across Georgia. These requirements sit at the intersection of plumbing code, environmental regulation, and local utility authority — making compliance a multi-agency obligation rather than a single permit matter. This page covers the classification of grease interceptor types, the regulatory framework applicable in Georgia, permitting and inspection expectations, and the operational boundaries that determine which requirements apply to a given facility.

Definition and scope

A grease trap — formally classified as a grease interceptor in plumbing and environmental codes — is a plumbing device designed to capture fats, oils, and grease (FOG) before wastewater enters the municipal sewer system or an on-site septic system. In Georgia, the applicable framework is rooted in the Georgia State Minimum Standard Plumbing Code, which adopts the International Plumbing Code (IPC) as modified by state amendments administered through the Georgia Department of Community Affairs (DCA).

Grease interceptors are mandatory for facilities that produce FOG-laden wastewater as a byproduct of food preparation, dishwashing, or commercial cooking. The obligation is not limited to restaurants: food processing plants, institutional cafeterias, bakeries, and commissary kitchens all fall within scope. Facilities producing only incidental FOG — such as office break rooms or retail food counters with limited cooking — may seek a determination from the local authority having jurisdiction (AHJ) regarding exemption.

Scope limitations: This page addresses Georgia-specific state plumbing code requirements and local authority frameworks. Federal EPA pretreatment standards under 40 CFR Part 403 may impose additional obligations on facilities discharging to publicly owned treatment works (POTWs), but those federal requirements fall outside the state plumbing scope covered here. Municipal ordinances in cities such as Atlanta, Savannah, or Augusta may impose standards stricter than the state minimum — those local amendments are addressed through local amendments to the Georgia plumbing code and are not replicated here. Septic-connected facilities have parallel obligations under Georgia EPD (Environmental Protection Division) rules that are partially distinct from those governing sewer-connected systems.

How it works

Georgia's regulatory context for Georgia plumbing establishes two primary interceptor classifications: hydromechanical grease interceptors (HGI) and gravity grease interceptors (GGI). These two categories differ in capacity, installation location, and maintenance frequency.

Hydromechanical grease interceptors (HGI):
- Installed indoors, typically under a sink or in a floor-mounted configuration
- Rated by flow capacity in gallons per minute (GPM), commonly 20 GPM to 100 GPM for commercial applications
- Designed for lower-volume FOG-generating fixtures
- Require more frequent cleaning — typically every 1 to 3 weeks — due to smaller retention capacity
- Governed by ASME A112.14.3 standards for performance verification

Gravity grease interceptors (GGI):
- Installed underground, external to the building
- Rated by liquid capacity in gallons, with a 1,000-gallon minimum capacity common under IPC Table 1003.3.4 for larger food service establishments
- Serve higher-volume kitchens and multi-fixture systems
- Typically pumped and cleaned every 30 to 90 days, with frequency determined by a 25% solids accumulation rule under IPC guidelines
- Required when total connected fixture flow rate exceeds the practical capacity of an HGI

Sizing calculations under the IPC methodology incorporate the number and type of drainage fixtures connected, the flow rate of each fixture in GPM, and a retention time factor. The Georgia Plumbing Authority home reference provides orientation to the broader code framework within which these calculations occur.

Common scenarios

The following scenarios represent typical grease trap compliance situations encountered by facilities and licensed plumbing contractors in Georgia:

New restaurant construction: A permit application for a new food service establishment triggers a mandatory grease interceptor plan review. The plumbing contractor must submit interceptor sizing calculations, fixture schedules, and installation details to both the local building department and, where applicable, the local wastewater utility authority. Review by two separate entities is standard in most Georgia counties.
Tenant build-out in an existing commercial space: A change of occupancy to a food service use requires retroactive interceptor installation even when the base building previously had none. The AHJ determines whether an HGI or GGI is required based on the proposed kitchen layout and fixture count.
Grease trap failure or backup: A blocked or undersized interceptor that causes sewage backup into a kitchen is a code violation and may trigger an emergency inspection. Under O.C.G.A. § 8-2-20 et seq., the DCA framework authorizes local enforcement agencies to issue stop-work or stop-use orders pending correction.
Pumping and maintenance compliance: Local sewer authorities in Georgia frequently require FOG management plans, pump-out logs, and manifest records documenting grease waste disposal at licensed facilities. Atlanta's Department of Watershed Management, for example, maintains a FOG Control Program with specific reporting obligations for registered facilities.
Septic-connected establishments in rural counties: Facilities not served by municipal sewer must comply with both plumbing code interceptor requirements and Georgia EPD on-site sewage management rules under Chapter 511-3-1 of the Georgia Rules for On-Site Sewage Management Systems. The septic system designer and the plumbing contractor must coordinate sizing to prevent FOG loading from causing drainfield failure.

Decision boundaries

The determination of which grease interceptor type, size, and regulatory pathway applies to a facility turns on four primary variables:

Connection point: Sewer-connected facilities follow IPC-based sizing and local utility FOG program rules. Septic-connected facilities carry dual obligations under plumbing code and Georgia EPD rules.
Fixture load and flow rate: Facilities with a total connected fixture flow rate above 50 GPM are typically directed toward a GGI by the AHJ, regardless of preference for an indoor HGI unit.
Local amendment status: Georgia allows local governments to adopt amendments to the state minimum plumbing code. A facility in a jurisdiction with a stricter local FOG ordinance — such as minimum GGI capacity set above the IPC baseline — must meet the local standard. Verifying amendment status through the local building department is the first step before finalizing interceptor selection.
Inspection and permit pathway: Grease interceptor installation requires a plumbing permit issued by the local AHJ. Only a licensed master plumber or licensed plumbing contractor may pull the permit under Georgia licensing law. The rough-in and final inspections are conducted by a local plumbing inspector; in some jurisdictions a separate inspection by the wastewater utility is required before connection. The Georgia plumbing inspection process and Georgia plumbing permit application process pages detail the procedural steps applicable to these installations.

Facilities that alter kitchen operations significantly — adding cooking equipment, increasing seating capacity, or changing from limited to full-service food preparation — must reassess interceptor sizing. The original permitted installation may no longer meet code requirements under the revised fixture load, triggering a new permit and inspection cycle.

References

Explore This Site

Services & Options Key Dimensions and Scopes of Georgia Plumbing Regulations & Safety Georgia Plumbing in Local Context Tools & Calculators Septic Tank Size Calculator FAQ Georgia Plumbing: Frequently Asked Questions