Chapter 10 — TRAPS AND INTERCEPTORS
1014.3 Gravity Grease Interceptors. Required gravity
California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-09-10 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
grease interceptors shall comply with the provisions of Section 1014.3.1 through Section 1014.3.7.
1014.3.1 General. The provisions of this section shall apply to the design, construction, installation, and testing of commercial kitchen gravity grease interceptors.
1014.3.2 Waste Discharge Requirements. Waste discharge in establishments from fixtures and equipment
For SI units: 1 inch = 25.4 mm, 1 gallon per minute = 0.06 L/s, 1 gallon =
3.785 L
198 2025 CALIFORNIA PLUMBING CODE
TRAPS AND INTERCEPTORS
which contain grease, including but not limited to, scullery sinks, pot and pan sinks, dishwashers, soup kettles, and floor drains located in areas where grease-containing materials exist, shall be permitted to be drained into the sanitary waste through the interceptor where approved by the Authority Having Jurisdiction.
1014.3.2.1 Toilets and Urinals. Toilets, urinals, and other similar fixtures shall not drain through the interceptor.
1014.3.2.2 Inlet Pipe. Waste shall enter the interceptor through the inlet pipe.
1014.3.3 Design. Gravity interceptors shall be constructed in accordance with the applicable standard in Chapter 17 or the design approved by the Authority Having Jurisdiction.
1014.3.4 Location. Each grease interceptor shall be so installed and connected that it shall be easily accessible for inspection, cleaning, and removal of the intercepted grease. A gravity grease interceptor that complies with ANSI/CAN/IAPMO Z1001 shall not be installed in a
building where food is handled. Location of the grease interceptor shall meet the approval of the Authority Having Jurisdiction.
1014.3.4.1 Interceptors. Interceptors shall be placed as close as practical to the fixtures they serve.
1014.3.4.2 Business Establishment. Each
business establishment for which a gravity grease interceptor is required shall have an interceptor which shall serve that establishment unless other wise approved by the Authority Having Jurisdiction.
1014.3.4.3 Access. Each gravity grease interceptor shall be located to be readily accessible to the equipment required for maintenance.
1014.3.5 Construction Requirements. Gravity grease interceptors shall be designed to remove grease from effluent and shall be sized in accordance with this
section. Gravity grease interceptors shall also be designed to retain grease until accumulations can be removed by pumping the interceptor. When provided, a sample box shall be located at the outlet end of gravity grease interceptors so that the Authority Having Jurisdiction can periodically sample effluent quality.
1014.3.6 Sizing Criteria. The volume of the interceptor shall be determined by using Table 1014.3.6. Where drainage fixture units (DFUs) are not known, the interceptor shall be sized based on the maximum DFUs allowed for the pipe size connected to the inlet of the interceptor. Refer to Table 703.2, Drainage Piping, Horizontal.
1014.3.7 Abandoned Gravity Grease Intercep- tors. Abandoned grease interceptors shall be pumped and filled as required for abandoned sewers and sewage disposal facilities in Section 722.0.
| DRAINAGE FIXTURE UNITS1, 3 (DFUs) |
INTERCEPTOR VOLUME2 (gallons) |
|---|---|
8 |
500 |
21 |
750 |
35 |
1000 |
90 |
1250 |
| 172 | 1500 |
216 |
2000 |
307 |
2500 |
342 |
3000 |
428 |
4000 |
576 |
5000 |
720 |
7500 |
| 2112 | 10 000 |
2640 |
15 000 |
For SI units: 1 gallon = 3.785 L
Notes: 1 The maximum allowable DFUs plumbed to the kitchen drain lines that will be connected to the grease interceptor. 2 This size is based on DFUs, the pipe size from this code; Table 703.2; Useful Tables for flow in half-full pipes (ref: Mohinder Nayyar Piping Handbook, 3rd Edition, 1992). Based on 30-minute retention time (ref.: George Tchobanoglous and Metcalf & Eddy. Wastewater Engineering Treatment, Disposal, and Reuse, 3rd Ed. 1991 & Ronald Crites and George Tchobanoglous. Small and Decentralized Wastewater Management Systems, 1998). Rounded up to nominal interceptor volume. 3 Where the flow rate of directly connected fixture(s) or appliance(s) have no assigned DFU values, the additional grease interceptor volume shall be based on the known flow rate (gpm) (L/s) multiplied by 30 minutes.
EXAMPLE 1014.3.6
GRAVITY GREASE INTERCEPTOR SIZING EXAMPLE
Given: A restaurant with the following fixtures and equip ment.
One food preparation sink; three-floor drains - one in the food prep area, one in the grill area, and one receiving the indirect waste from the ice machine and a mop sink.
Kitchen Drain Line DFU Count (from Table 702.1):
3 floor drains at 2 DFUs each = 6 DFUs
Mop sink at 3 DFUs each = 3 DFUs
Food prep sink at 3 DFUs each = 3 DFUs
Total = 12 DFUs
Using Table 1014.3.6, the grease interceptor will be sized at 750 gallons (2389 L).
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Ask AI about this code▸Contents — California Plumbing Code (Title 24, Part 5)
- Chapter 1 — GENERAL CODE PROVISIONS
- Chapter 2 — DEFINITIONS
- Chapter 3 — GENERAL REGULATIONS
- Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
- Chapter 5 — WATER HEATERS
- Chapter 6 — WATER SUPPLY AND DISTRIBUTION
- Chapter 7 — SANITARY DRAINAGE
- Chapter 8 — INDIRECT WASTES
- Chapter 9 — VENTS
▸Chapter 10 — TRAPS AND INTERCEPTORS
Overview- 1001.1 Applicability. This chapter shall govern the materials,…
- 1001.2 Where Required. Each plumbing fixture shall be separate…
- 1002.1 Vent Pipes. Each plumbing fixture trap, except as
- 1002.2 Fixture Traps. Each fixture trap shall have a protectin…
- 1002.3 Change of Direction. A trap arm shall be permitted to c…
- 1002.4 Vent Pipe Opening. The vent pipe opening from
- 1003.1 General Requirements. Each trap, except for
- 1003.2 Slip Joint Fittings. A maximum of one approved
- 1003.3 Size. The size (nominal diameter) of a trap for a
- 1004.1 Prohibited. No form of trap that depends for its seal
- 1004.2 Movable Parts. Bladders, check valves or another
- 1005.1 General. Each fixture trap shall have a liquid seal of
- 1006.1 General. Floor drains shall connect into a trap so
- 1007.1 General. Floor drain or similar traps directly connecte…
- 1007.2 Trap Seal Primers. Potable water supply trap seal
- 1008.1 General. Building traps shall not be installed except
- 1009.1 Where Required. Interceptors (clarifiers) (including gr…
- 1009.2 Approval. The size, type, and location of each intercep…
- 1009.3 Design. Interceptors (clarifiers) for sand and similar …
- 1009.4 Relief Vent. Interceptors (clarifiers) shall be so
- 1009.5 Location. Each interceptor (clarifier) cover shall be
- 1009.6 Maintenance of Interceptors. Interceptors shall
- 1009.7 Discharge. The waste pipe from oil and sand interceptor…
- 1010.1 General. A fish, fowl, and animal slaughterhouse or
- 1010.2 Meat and Poultry Processing Plants. [AGR]
- 1010.3 Collection Centers and Facilities. [AGR] All
- 1010.4 Horse Meat and Pet Food Establishments.
- 1010.5 Draining and Plumbing. [AGR] There shall be
- 1011.1 General. A private or public wash rack or floor or
- 1012.1 General. Laundry equipment in commercial and
- 1013.1 General. Bottling plants shall discharge their process
- 1014.1 General. Where it is determined by the Authority
- 1014.2 Hydromechanical Grease Interceptors. Plumbing fixtures …
- 1014.3 Gravity Grease Interceptors. Required gravity
- 1015.1 Purpose. The purpose of this section is to provide
- 1015.2 Components, Materials, and Equipment. FOG
- 1015.3 Sizing and Installation. FOG disposal systems
- 1015.4 Performance. FOG disposal systems shall produce
- 1015.5 [OSHPD 1, 1R, 2, 3, 4 & 5] Grease interceptors
- 1015.6 [OSHPD 1, 1R, 2, 3, 4 & 5] Grease interceptors
- 1016.1 Discharge. Where the discharge of a fixture or drain
- 1016.2 Authority Having Jurisdiction. Sand interceptors
- 1016.3 Construction and Size. Sand interceptors shall be
- 1016.4 Separate Use. Sand and similar interceptors for
- 1017.1 Interceptors Required. Repair garages and gasoline stat…
- 1017.2 Interceptor Design Alternatives. Oil interceptors
- 1017.3 Interceptor Details. Oil and flammable liquid intercept…
- 1017.4 Design of Interceptors. Each manufactured interceptor t…
- Chapter 11 — STORM DRAINAGE
- Chapter 12 — FUEL GAS PIPING
- Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
- Chapter 14 — FIRESTOP PROTECTION
- Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
- Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
- Chapter 17 — REFERENCED STANDARDS
- Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
- Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
- Appendix C — ALTERNATE PLUMBING SYSTEMS
- Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
- Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
- Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
- Appendix G — SIZING OF VENTING SYSTEMS
- Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
- Appendix I — INSTALLATION STANDARDS
- Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
- Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
- Appendix L — SUSTAINABLE PRACTICES
- Appendix M — PEAK WATER DEMAND CALCULATOR
- Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
- Appendix O — NON-SEWERED SANITATION SYSTEMS
- Appendix P — PROFESSIONAL QUALIFICATIONS
- Appendix Q — INDOOR HORTICULTURAL FACILITIES
- Appendix R — TINY HOUSES
- Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS