Prepared by GreaseTrapLocator · Fact review: August 9, 2026
A gravity grease interceptor is one type of grease-interceptor system considered during a commercial food-service project. The approved size, configuration, connected fixtures, and records for a specific project come from the local authority and the approved design—not from a restaurant type, seat count, or a generic gallon chart.
Gravity-interceptor terminology
The City of Toronto describes a gravity grease interceptor as a large in-ground interceptor that holds wastewater for about 30 minutes so fats, oils, and grease can rise while solids settle. Toronto lists a local example range of 300 to 2,000 gallons and notes that these units can receive discharge from multiple plumbing fixtures. Those details are a Toronto example, not a sizing rule for another city or province. [1]
Taken together, the differently labelled fields in the Toronto guidance, Austin’s local calculation method, and the separately stated ratings for the named Schier model show why the measurements on a proposal must remain separate. A flow rating, liquid capacity, grease-retention value, fixture-unit count, and retention time answer different questions. This is a conservative inference from those sources, not a new conversion rule. Do not use meals, seats, or cuisine as a substitute for local review. [1][2][3]
Why local plan review determines the project
Local programs can use different review methods. For example, Austin Water says not to purchase a grease trap or interceptor before building-plan approval and an Industrial Waste approval letter that states the required size and design. Austin’s published method is specific to Austin, including its fixture-unit, flow-rate, and liquid-holding-capacity process. [2]
Toronto requires a building permit to install or replace a grease interceptor and says the installation must follow the Ontario Building Code. That is Toronto/Ontario guidance, not a universal permit statement. [1]
Documents to gather before a proposal is reviewed
Ask the local authority or project team what it needs for the site. Useful project records can include the local approval or permit path, the approved plumbing plan, and the current documents for the exact equipment being proposed. Toronto says that, when product markings are no longer visible after installation, the establishment must keep the manufacturer and installation drawings on site for inspection if requested. [1]
For a named-product example, Schier’s GB-1000 product page lists 100- and 200-GPM configurations and a 1,000-gallon liquid-capacity configuration. Those are facts about that product line only; they do not establish a project size, local approval, or a comparison with another device. [3]
Plan for access and future service through the approved design
Toronto requires a grease interceptor to be installed where it is easily accessible for maintenance and inspection. The exact access, cover, loading, placement, and service requirements for a project should come from the approved plan, the local authority, and the documentation for the selected equipment. [1]
Do not use this page as an installation guide. Excavation and utility work have workplace safety requirements; OSHA’s excavation standard includes protections for locating underground installations. The project team should use the applicable local requirements and qualified workers for the work. [4]
Frequently asked questions
What is a gravity grease interceptor?
Toronto describes a gravity grease interceptor as a large in-ground interceptor that holds wastewater for about 30 minutes while fats, oils, and grease rise and solids settle. That description is a Toronto example; the local authority and approved design control a specific project. [1]
Does a gallon label determine the interceptor size I need?
No. A liquid-capacity label is one item on an equipment document. The local examples and named-product record used here keep capacity and other ratings separate; local approval and the project’s approved design determine what is required for a specific site. [1][2][3]
What should I bring to local plan review?
Ask the local authority what it requires. Keep the approved plan and the current documents for the exact proposed equipment. Toronto says manufacturer and installation drawings must be kept on site when product markings are not visible after installation. [1]
Can this page tell me where or how to install an interceptor?
No. Placement and installation details belong in the approved site plan, local requirements, and the selected product’s current documentation. Toronto’s accessibility statement is a local example; this page does not provide installation instructions. [1]
Can a manufacturer page size my restaurant?
No. The cited Schier page documents ratings and configurations for its named GB-1000 product line only. It does not replace local approval or an approved project design. [3]
Sources
- City of Toronto, “Grease Interceptor Installation” (modified May 14, 2026; accessed August 9, 2026). Toronto/Ontario only.
- Austin Water, “Grease Trap Sizing & Design Criteria” (accessed August 9, 2026). Austin, Texas only.
- Schier Products, “GB-1000 Grease Interceptor” (accessed August 9, 2026). Named product line only.
- OSHA, “29 CFR 1926.651 Specific Excavation Requirements” (accessed August 9, 2026). U.S. workplace safety boundary only.
Author: Grease Trap Locator Editorial Team
The Grease Trap Locator editorial team covers FOG compliance, grease trap maintenance, and commercial kitchen regulations across the US and Canada. Our guides are written for restaurant owners, facility managers, and food service operators who need practical, accurate information without the fluff.
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