CPC · California Plumbing Code
Approved interceptor standards, AHJ approval, location and maintenance
If your building needs a grease, oil, sand or solid interceptor, pick a unit listed to one of the standards in Table 1009.1, get the AHJ’s approval for its size/type/location, and keep it clean with periodic removal of accumulated material — the requirements are in **§ 1009.1**, **§ 1009.2**, **§ 1009.6** and **§ 1009.7**.
Last reviewed: July 6, 2026
What the code requires — plain English (controlling §§)
Interceptors (also called clarifiers) must be used where necessary to protect the building drain, sewer or disposal system, and the code lists the acceptable standards for different applications — see § 1009.1. The size, type and location of every interceptor must be approved by the Authority Having Jurisdiction (AHJ) and only wastes that require treatment may be discharged to the interceptor — see § 1009.2. Interceptors must be kept in efficient operating condition by periodic removal of accumulated grease, oil, scum or solids — see § 1009.6. Discharge from oil and sand interceptors must be as approved by the AHJ — see § 1009.7.
The single most important rule: have the right type of interceptor (per Table 1009.1) and get the AHJ’s approval for its size, type and location — then maintain it by periodic cleaning. § 1009.1, § 1009.2, § 1009.6.
Requirements in detail
Defined terms (first use)
- interceptor (clarifier) — the device that removes grease, oil, sand or solids from wastewater (term used throughout § 1009.1).
- Authority Having Jurisdiction (AHJ) — the official or agency that reviews and approves the size, type and location of interceptors per § 1009.2.
Approved standards (Table summary)
The code provides a table of acceptable standards for different interceptor applications (Table 1009.1). Below is a decision-oriented extract you will use when selecting equipment:
| Application | Acceptable standard(s) | Code reference |
|---|---|---|
| Fats, oil, grease (FOG) | ASME A112.14.3, ASME A112.14.4, ASME A112.14.6, CSA B481, ANSI/CAN/IAPMO Z1001, PDI G-101, PDI G-102 | Table 1009.1 / § 1009.1 |
| Solid waste interceptors | IAPMO IGC 167 | Table 1009.1 / § 1009.1 |
| Non‑petroleum oil separators | ASME A112.14.6, IAPMO PS 80, PDI G-102 | Table 1009.1 / § 1009.1 |
| Petroleum oil separators | ASTM D6104, IAPMO IGC 183, IAPMO IGC 325 | Table 1009.1 / § 1009.1 |
(Use the specific standard called out in the table to confirm a product’s listing/certification before submitting to the AHJ.)
AHJ approval: what must be approved
- The size, type, and location of every interceptor (clarifier) or separator must be approved by the AHJ. This is a mandatory review step before installation. § 1009.2
- The code also prohibits discharging wastes into an interceptor except those specifically requiring treatment or separation (so don’t plan to route miscellaneous wastes into the unit). § 1009.2
Maintenance requirements
- Interceptors must be maintained in efficient operating condition through periodic removal of accumulated grease, scum, oil or floating substances and solids. The code does not prescribe a specific interval — the obligation is that cleaning be periodic and effective. § 1009.6
- If the AHJ determines maintenance is inadequate, the AHJ has authority to require additional equipment or a maintenance program (see related grease‑interceptor provisions in the code).
Discharge requirements
- The waste pipe from oil and sand interceptors must discharge as approved by the AHJ (the AHJ may limit destination, sampling, or require connection to a specific system). § 1009.7
Exceptions & special cases
The controlling sections cited here ( § 1009.1, § 1009.2, § 1009.6, § 1009.7 ) do not enumerate numeric cleaning intervals or detailed placement/accessibility rules — they require AHJ approval and periodic maintenance but leave specific frequency, sampling, or alternative designs to the AHJ or to other sections of the code and referenced standards. See Table 1009.1 for the list of acceptable standards that may have additional requirements. § 1009.1, § 1009.2, § 1009.6, § 1009.7.
If you need more prescriptive sizing, venting, or access requirements, other sections (for example the grease‑interceptor chapter and design provisions) and the listed standards contain those details — those are related provisions (listed below). The four controlling sections themselves do not supply every design number or cleaning interval.
Common mistakes
- Assuming any “grease trap” is acceptable without verifying it meets one of the standards in Table 1009.1 (must choose an interceptor built to an accepted standard). § 1009.1
- Installing without AHJ approval of size, type or location — the AHJ approval step is mandatory. § 1009.2
- Treating “periodic removal” as optional — the code requires maintenance to keep interceptors in efficient operating condition. § 1009.6
- Discharging non‑authorized wastes into the interceptor or routing the interceptor’s outlet to an unapproved location. § 1009.2, § 1009.7
Worked example — restaurant FOG interceptor (process, not a sizing calculation)
Scenario: A new full‑service restaurant will produce FOG‑laden wastewater. Steps to comply with the CPC controlling sections:
- Product selection — choose a grease interceptor listed to an accepted standard for FOG (for example, a model certified to ASME A112.14.3 or PDI G‑101 as shown in Table 1009.1). Table 1009.1 / § 1009.1.
- Plans & AHJ review — submit the selected model data (manufacturer spec sheet showing the listed standard), proposed size, and location on the building plans for AHJ approval; the AHJ must approve size, type, and location per § 1009.2.
- Installation & discharge — install per manufacturer instructions and the approved plans; ensure outlet/discharge routing is consistent with AHJ direction (discharge approval required by § 1009.7).
- Maintenance plan — establish a documented periodic cleaning/maintenance program (the code requires periodic removal to maintain efficient operation; cleaning frequency is not specified in § 1009.6 and is often set by the AHJ or local ordinance). § 1009.6.
Note: The CPC controlling sections require AHJ approval and periodic maintenance but do not supply the numeric cleaning interval or detailed sizing rules in these specific sections; those details are found in referenced standards and related CPC sections.
Related provisions (select CPC sections that commonly apply)
- § 1009.1 — Where interceptors are required; Table 1009.1 lists acceptable standards.
- § 1009.2 — AHJ approval of size, type, and location; limitation on wastes discharged.
- § 1009.6 — Maintenance (periodic removal).
- § 1009.7 — Discharge of oil and sand interceptors as approved by AHJ.
- For detailed grease interceptor design, sizing, venting, access and construction: see the grease‑interceptor sections (for example § 1014.1 and following) and their tables and referenced standards (these sections add prescriptive sizing tables and vent/flow‑control requirements).
Code references
Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:
CPC § 1009.1 High relevance — show source text
TABLE 1009.1 APPROVED INTERCEPTORS (CLARIFIERS)
APPLICATION STANDARD
Fats, Oil, Grease
(FOG)ASME A112.14.3, ASME A112.14.4,
ASME A112.14.6, CSA B481,
ANSI/CAN/IAPMO Z1001,
PDI G-101, PDI G-102Solid Waste IAPMO IGC 167
Non-petroleum OilASME A112.14.6, IAPMO PS 80,
PDI G-102
Petroleum OilASTM D6104, IAPMO IGC 183,
IAPMO IGC 3251009.2 Approval. The size, type, and location of each interceptor (clarifier) or separator shall be approved by the Authority Having Jurisdiction. Except where otherwise specifically permitted, no wastes other than those requiring treatment or separation shall be discharged into an interceptor (clarifier). 1009.3 Design. Interceptors (clarifiers) for sand and similar heavy solids shall be so designed and located as to be readily accessible for cleaning and shall have a water seal of not less than 6 inches (152 mm). 1009.4 Relief Vent. Interceptors (clarifiers) shall be so designed that they will not become air-bound where closed covers are used. Each interceptor (clarifier) shall be properly vented.
1009.5 Location. Each interceptor (clarifier) cover shall be readily accessible for servicing and maintaining the interceptor (clarifier) in working and operating condition. The use of ladders or the removal of bulky equipment to service interceptors (clarifiers) shall constitute a violation of accessibility. Location of interceptors (clarifiers) shall be shown on the approved building plan. 1009.6 Maintenance of Interceptors. Interceptors shall be maintained in efficient operating condition by periodic removal of accumulated grease, scum, oil, or other floating substances and solids deposited in the interceptor. 1009.7 Discharge. The waste pipe from oil and sand interceptors shall discharge as approved by the Authority Having Jurisdiction.
1010.0 Slaughterhouses, Packing Establishments, etc.
1010.1 General. A fish, fowl, and animal slaughterhouse or establishment; a fish, fowl, and meat packing or curing establishment; a soap factory, tallow-rendering, fat-rendering, and a hide-curing establishment shall be connected to and shall drain or discharge into an approved grease interceptor (clarifier).
TABLE 1009.1 APPROVED INTERCEPTORS (CLARIFIERS)
196 2025 CALIFORNIA PLUMBING CODE
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
TRAPS AND INTERCEPTORS
1010.2 Meat and Poultry Processing Plants. [AGR]
1010.2.1 Drainage and Plumbing Systems. Drainage and plumbing systems shall meet the require- ments of Section 724.0.
1010.2.1.1 Each floor drain shall be equipped with a deep-seal trap.
CPC § 1009.1 High relevance — show source text
1009.1 Where Required . . . . . . . . . . . . . .196
Table 1009.1 Approved Interceptors (Clarifiers) . .196
1009.2 Approval . . . . . . . . . . . . . . . . . . . .196
1009.3 Design . . . . . . . . . . . . . . . . . . . . .196
2025 CALIFORNIA PLUMBING CODE xxxvii
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
TABLE OF CONTENTS
1009.4 Relief Vent . . . . . . . . . . . . . . . . . .196
1009.5 Location . . . . . . . . . . . . . . . . . . . .196
1009.6 Maintenance of Interceptors . . . . .196
1009.7 Discharge . . . . . . . . . . . . . . . . . . .196
1010.0 Slaughterhouses, Packing Establishments, etc . . . . . . . . . . .196
1010.1 General . . . . . . . . . . . . . . . . . . . . .196
1010.2 Meat and Poultry Processing Plants . . . . . . . . . . . . . . . . . . . . . .197
1010.3 Collection Centers and
Facilities . . . . . . . . . . . . . . . . . . . .197
1010.4 Horse Meat and Pet Food
Establishments . . . . . . . . . . . . . . .197
1010.5 Draining and Plumbing . . . . . . . .197
1011.0 Minimum Requirements for Auto Wash Racks . . . . . . . . . . . . .197
1011.1 General . . . . . . . . . . . . . . . . . . . . .197
1012.0 Commercial and Industrial
Laundries . . . . . . . . . . . . . . . . . . .197
1012.1 General . . . . . . . . . . . . . . . . . . . . .197
1013.0 Bottling Establishments . . . . . . . .197
1013.1 General . . . . . . . . . . . . . . . . . . . . .197
1014.0 Grease Interceptors . . . . . . . . . . .197
1014.1 General . . . . . . . . . . . . . . . . . . . . .197
1014.2 Hydromechanical Grease Interceptors . . . . . . . . . . . . . . . . . .198
Table 1014.2.1 Hydromechanical Grease Interceptor Sizing Using Gravity Flow Rates . . . . . . . . . . . .198
1014.3 Gravity Grease Interceptors . . . . .198
Table 1014.3.6 Gravity Grease Interceptor Sizing . . . . . . . . . . . . . . . . . . . . . .199
CPC § 1014.1.1 High relevance — show source text
2025 CALIFORNIA PLUMBING CODE 197
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
TRAPS AND INTERCEPTORS
1014.1.1 Trapped and Vented. Each fixture discharging into a grease interceptor shall be individually trapped and vented in an approved manner.
1014.1.2 Maintenance. Grease interceptors shall be maintained in efficient operating condition by periodic removal of the accumulated grease and latent material. No such collected grease shall be introduced into drainage piping or a public or private sewer. Where the Authority Having Jurisdiction determines that a grease interceptor is not being properly cleaned or maintained, the Authority Having Jurisdiction shall have the authority to mandate the installation of additional equipment or devices and to mandate a maintenance program.
1014.1.3 Food Waste Disposers and Dishwash- ers. No food waste disposer or dishwasher shall be connected to or discharge into a grease interceptor. Commercial food waste disposers shall be permitted to discharge directly into the building’s drainage system.
Exception: Food waste disposers shall be permitted to discharge to grease interceptors that are designed to receive the discharge of food waste.
1014.2 Hydromechanical Grease Interceptors. Plumbing fixtures or equipment connected to a Type A and B hydromechanical grease interceptor shall discharge through an approved type of vented flow control installed in a readily accessible and visible location. Flow control devices shall be
designed and installed so that the total flow through such device or devices shall at no time be greater than the rated flow of the connected grease interceptor. No flow control device having adjustable or removable parts shall be approved. The vented flow control device shall be located such that no system vent shall be between the flow control and the grease interceptor inlet. The vent or air inlet of the flow control device shall connect with the sanitary drainage vent system, as elsewhere required by this code, or shall terminate through the roof of the building, and shall not terminate to the free atmosphere inside the building.
Exception: Listed grease interceptors with integral flow controls or restricting devices shall be installed in an accessible location in accordance with the manufacturer’s installation
instructions.
1014.2.1 Capacity. The total capacity in gallons (gal) (L) of fixtures discharging into a hydromechanical grease interceptor shall not exceed two and one-half times the certified gallon per minute (gpm) (L/s) flow rate of the interceptor in accordance with Table 1014.2.1.
For this section, the term “fixture” shall mean and include each plumbing fixture, appliance, apparatus, or other equipment required to be connected to or discharged into a grease interceptor by a provision of this section.
1014.2.2 Vent. A vent shall be installed downstream of
hydromechanical grease interceptors in accordance with the requirements of this code.
TABLE 1014.2.1
HYDROMECHANICAL GREASE INTERCEPTOR SIZING USING GRAVITY FLOW RATES [1]
CPC § 3.785 High relevance — show source text
3.785 L
1014.3 Gravity Grease Interceptors. Required gravity 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
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
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.
CPC § 1003.2 High relevance — show source text
1003.2 Slip Joint Fittings . . . . . . . . . . . . .195
1003.3 Size . . . . . . . . . . . . . . . . . . . . . . . .195
1004.0 Traps . . . . . . . . . . . . . . . . . . . . . .196
1004.1 Prohibited . . . . . . . . . . . . . . . . . . .196
1004.2 Movable Parts . . . . . . . . . . . . . . . .196
1005.0 Trap Seals . . . . . . . . . . . . . . . . . .196
1005.1 General . . . . . . . . . . . . . . . . . . . . .196
1006.0 Floor Drain Traps . . . . . . . . . . . . .196
1006.1 General . . . . . . . . . . . . . . . . . . . . .196
1007.0 Trap Seal Protection . . . . . . . . . . .196
1007.1 General . . . . . . . . . . . . . . . . . . . . .196
1007.2 Trap Seal Primers . . . . . . . . . . . .196
1008.0 Building Traps . . . . . . . . . . . . . . . .196
1008.1 General . . . . . . . . . . . . . . . . . . . . .196
1009.0 Interceptors (Clarifiers) and Separators . . . . . . . . . . . . . . . . . .196
1009.1 Where Required . . . . . . . . . . . . . .196
Table 1009.1 Approved Interceptors (Clarifiers) . .196
1009.2 Approval . . . . . . . . . . . . . . . . . . . .196
1009.3 Design . . . . . . . . . . . . . . . . . . . . .196
2025 CALIFORNIA PLUMBING CODE xxxvii
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
TABLE OF CONTENTS
1009.4 Relief Vent . . . . . . . . . . . . . . . . . .196
1009.5 Location . . . . . . . . . . . . . . . . . . . .196
1009.6 Maintenance of Interceptors . . . . .196
1009.7 Discharge . . . . . . . . . . . . . . . . . . .196
1010.0 Slaughterhouses, Packing Establishments, etc . . . . . . . . . . .196
1010.1 General . . . . . . . . . . . . . . . . . . . . .196
1010.2 Meat and Poultry Processing Plants . . . . . . . . . . . . . . . . . . . . . .197
1010.3 Collection Centers and
Facilities . . . . . . . . . . . . . . . . . . . .197
1010.4 Horse Meat and Pet Food
CPC § 1007.2 Medium relevance — show source text
1007.2 Trap Seal Primers. Potable water supply trap seal primer valves shall comply with ASSE 1018. Drainage or electronic design type trap seal primer devices shall comply with ASSE 1044 or IAPMO PS 76.
1008.0 Building Traps. 1008.1 General. Building traps shall not be installed except where required by the Authority Having Jurisdiction. Each building trap where installed shall be provided with a cleanout and with a relieving vent or fresh-air intake on the inlet side of the trap, which needs not be larger than one-half the diameter of the drain to which it connects. Such relieving vent or fresh-air intake shall be carried above grade and terminate in a screened outlet located outside the building.
1009.0 Interceptors (Clarifiers) and Separators.
1009.1 Where Required. Interceptors (clarifiers) (including grease, oil, sand, solid interceptors, etc.) shall be required
by the Authority Having Jurisdiction where they are necessary for the proper handling of liquid wastes containing grease, flammable wastes, sand, solids, acid or alkaline substances, or other ingredients harmful to the building drainage system, the public or private sewer, or to public or private sewage disposal. A list of acceptable interceptor standards is referenced in Table 1009.1.
TABLE 1009.1 APPROVED INTERCEPTORS (CLARIFIERS)
APPLICATION STANDARD
Fats, Oil, Grease
(FOG)ASME A112.14.3, ASME A112.14.4,
ASME A112.14.6, CSA B481,
ANSI/CAN/IAPMO Z1001,
PDI G-101, PDI G-102Solid Waste IAPMO IGC 167
Non-petroleum OilASME A112.14.6, IAPMO PS 80,
PDI G-102
Petroleum OilASTM D6104, IAPMO IGC 183,
IAPMO IGC 3251009.2 Approval. The size, type, and location of each interceptor (clarifier) or separator shall be approved by the Authority Having Jurisdiction. Except where otherwise specifically permitted, no wastes other than those requiring treatment or separation shall be discharged into an interceptor (clarifier). 1009.3 Design. Interceptors (clarifiers) for sand and similar heavy solids shall be so designed and located as to be readily accessible for cleaning and shall have a water seal of not less than 6 inches (152 mm). 1009.4 Relief Vent. Interceptors (clarifiers) shall be so designed that they will not become air-bound where closed covers are used. Each interceptor (clarifier) shall be properly vented.
CPC § 901.0 Medium relevance — show source text
H 901.0 Commercial or Industrial Special Liquid- Waste Disposal.
H 901.1 Interceptor. Where liquid wastes contain excessive amounts of grease, garbage, flammable wastes, sand, or other ingredients that affect the operation of a private sewage disposal system, an interceptor for such wastes shall be installed.
H 901.2 Installation. Installation of such interceptors shall comply with Section 1009.0 of this code, and their location shall comply with Table H 101.8 of this appendix. H 901.3 Sampling Box. A sampling box shall be installed where required by the Authority Having Jurisdiction. H 901.4 Design and Structural Requirement. Interceptors shall be of approved design and be not less than two compartments. Structural requirements shall comply with Section H 501.0 of this appendix.
H 901.5 Location. Interceptors shall be located as close to the source as possible and be accessible for servicing. Necessary manholes for servicing shall be at grade level and be gastight.
H 901.6 Waste Discharge. Waste discharge from interceptors shall be permitted to be connected to a septic tank or other primary system or be disposed into a separate disposal system. H 901.7 Design Criteria. A formula shall be permitted to be adapted to other types of occupancies with similar wastes. (See Chart H 901.7)
H 1001.0 Inspection and Testing. H 1001.1 Inspection. Inspection requirements shall comply with the following:
(1) Applicable provisions of Section 105.0 of this code and this appendix shall be required. Plans shall be required in accordance with Section 103.3 of this code.
(2) System components shall be properly identified as to manufacturer. Septic tanks or other primary systems shall have the rated capacity permanently marked on the unit.
(3) Septic tanks or other primary systems shall be installed on dry, level, well-compacted soil.
(4) Where design is predicated on soil tests, the system shall be installed at the same location and depth as the tested
area.
H 1001.2 Testing. Testing requirements shall comply with the following:
(1) Septic tanks or other primary components shall be filled with water to flow line before requesting an inspection. Seams or joints shall be left exposed (except the bottom), and the tank shall remain watertight.
(2) A flow test shall be performed through the system to the point of effluent disposal. All lines and components shall
CHART H 901.7
RECOMMENDED DESIGN CRITERIA
GREASE AND GARBAGE, COMMERCIAL KITCHENS Number of meals per peak hour x Waste flow rate [1] x Retention time [2] x Storage factor [3] = (Interceptor size liquid capacity)
SAND-SILT OIL, AUTO WASHERS vehicles Number of per hour x Waste flow rate [1] x Retention time [2] x Storage factor [3] = (Interceptor size liquid capacity)
SILT-LINT GREASE, LAUNDRIES, LAUNDROMATS
Number of x 2 cycles per x Waste flow x Retention time [2] = Storage factor [3] = Interceptor size machines hour rate [1] (liquid capacity)
Notes: 1 For waste flow rate see Table H 201.1(4). 2 Retention Times:
CPC § 101.2.2 Medium relevance — show source text
CFC—25: California Fire Code
101.2.2, 101.4.2, 301.3.1, 302.2, 307.1, 308.1, 802.2.1, 802.2.3, 803.2.3, 803.4.1.1, 803.4.1.2, 803.4.1.3, 803.4.1.4, 803.4.1.5, 803.4.1.6, Table 804.5.1.1(1), 904.1.5, 1011.6.1.1, 1303.1.2, 1305.2.8.1, 1305.2.14, 1305.2.14.1, 1401.2, 1501.1, 1501.5, 1502.1, 1502.1.1, 1502.2, 1502.3, 1504.1, 1507.1, 1507.2
CMC—25: California Mechanical Code
302.2, 702.7, 807.1, 902.1.1, 1008.1, 1305.2.7.1, 1305.2.8, 1305.2.8.1
CPC—25: California Plumbing Code
302.2, 408.1, 702.7, 1009.1, 1009.2, 1009.3, 1009.5, 1302.1.6, 1503.1
16-4 2025 CALIFORNIA EXISTING BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
REFERENCED STANDARDS
CRC—25: California Residential Code
101.2, 101.4.1, 104.3.1, 109.3.3, 109.3.10, 302.2, 307.1, 308.1, 401.3, 402.1, 405.2.6, 502.2, 502.3, 502.4, 503.2, 503.3, 503.11, 505.2, 505.3, 507.3, 701.3, 702.4, 702.5, 706.2, 708.1, 805.2, 806.4, 809.1, 906.2, 907.1, 1011.2.1, 1103.1, 1103.2, 1103.3, 1104.1, 1201.4, 1302.1.2, 1302.1.3, 1302.1.3, 1303.1.3, 1401.2, 1402.1, 1402.2, 1402.2.1, 1402.3, 1402.4, 1402.5, 1402.6
ICC 300—2023: ICC Standard on Bleachers, Folding and Telescopic Seating and Grandstands
301.1.1, 401.1.1, 1401.1.1
ICC A117.1—2017: Accessible and Usable Buildings and Facilities
CPC § 1014.3.4 Medium relevance — show source text
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)
8500
21750
351000
901250 172 1500
2162000
3072500
3423000
4284000
5765000
7207500 2112 10 000
264015 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.
CPC § 101.3.2 Medium relevance — show source text
** No permit for a rainwater catchment system requiring a permit shall be issued until complete plumbing plans, with data satisfactory to the Authority Having Jurisdiction, have been submitted and approved. No changes or connections shall be made to either the rainfall catchment or the potable water system within a site containing a rainwater catchment water system without approval by the Authority Having Jurisdiction. K 101.3.2 System Changes. No changes or connections shall be made to either the rainwater catchment system or the potable water system within a site containing a rainwater catchment system requiring a permit without approval by the Authority Having Jurisdiction. K 101.4 Product and Material Approval. System components shall be properly identified as to the manufacturer. K 101.4.1 Plumbing Materials and Systems. Pipe, pipe fittings, traps, fixtures, material, and devices used in a potable rainwater system shall be listed or labeled (thirdparty certified) by a listing agency (accredited conformity assessment body) and shall be in accordance with approved applicable recognized standards referenced within this code, and shall be free from defects. Unless otherwise provided for in this appendix, materials, fixtures, or devices used or entering into the construction of plumbing systems, or parts thereof shall be submitted to the Authority Having Jurisdiction for approval.
K 101.5 Maintenance and Inspection. Potable rainwater catchment systems and components shall be inspected and maintained in accordance with Section K 101.5.1 through Section K 101.5.3.
K 101.5.1 Frequency. Potable rainwater catchment systems and components shall be inspected and maintained in accordance with Table K 101.5.1 unless more
frequent inspection and maintenance are required by the manufacturer.
K 101.5.2 Maintenance Log. A maintenance log for potable rainwater catchment systems shall be maintained by the property owner and be available for inspection. The property owner or designated appointee shall ensure that a record of testing, inspection, and maintenance in accordance with Table K 101.5.1 is maintained in the log. The log will indicate the frequency of inspection, and maintenance of each system. A record of the required water quality tests shall be retained for not less than 2 years.
K 101.5.3 Maintenance Responsibility. The required maintenance and inspection of potable rainwater catchment systems shall be the responsibility of the property owner unless otherwise required by the Authority Having Jurisdiction.
K 101.6 Operation and Maintenance Manual. An operation and maintenance manual for potable rainwater catchment systems shall be supplied to the building owner by the system designer. The operating and maintenance manual shall include the following:
(1) Detailed diagram of the entire system and the location of system components.
(2) Instructions for operating and maintaining the system.
(3) Details on maintaining the required water quality as determined by the Authority Having Jurisdiction.
(4) Details on deactivating the system for maintenance, repair, or other purposes.
(5) Applicable testing, inspection, and maintenance frequencies in accordance with Table K 101.5.1.
(6) A method of contacting the manufacturer(s).
CPC § 0.06 Medium relevance — show source text
For SI units: 1 inch = 25 mm, 1 gallon per minute = 0.06 L/s
Notes: 1 For interceptor sizing by the fixture capacity see the example below. 2 1 ∕ 4 inch slope per foot (20.8 mm/m) based on Manning’s formula with friction factor N = 0.012.
EXAMPLE 1014.2.1
SIZING HYDROMECHANICAL GREASE INTERCEPTOR(S)
USING FIXTURE CAPACITY
Step 1: Determine the flow rate from each fixture.
[Length] X [Width] X [Depth] / [231] = Gallons X [0.75 fill factor] / [Drain
Period (1 minute or 2 minutes)]
Step 2: Calculate the total load from fixtures that discharge into
the interceptor.
FIXTURES COMPART-
MENTSLOAD
(gallons)SIZE OF
GREASE
INTERCEPTOR
ONE-MINUTE
DRAINAGE
PERIOD
(gpm)TWO-
MINUTE
DRAINAGE
PERIOD
(gpm)
Compartment
size–– –– –– ––
24 inches x 24
inches x 12
inches2 44.9 –– ––
Hydrant–– 3 –– ––
Rated
Appliance–– 2 –– ––
–––– 49.9 50 25 For SI units: 1 inch = 25.4 mm, 1 gallon per minute = 0.06 L/s, 1 gallon =
3.785 L
1014.3 Gravity Grease Interceptors. Required gravity 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
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
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.
CPC § 31F-93 Medium relevance — show source text
Piping that may be exposed to the low temperature of LNG or to the heat of an ignited spill, during an emer-_ gency where such exposure could result in a failure of the piping, shall comply with at least one of the following: (a) Made of material(s) that can withstand both the normal operating temperature and extreme temperature to which the piping may be subjected during the emergency
2025 CALIFORNIA BUILDING CODE 31F-93
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MARINE OIL TERMINALS
(b) Protected by insulation or other means to delay failure due to extreme temperatures until corrective action can be taken by the operator. (c) Capable of being isolated and having the flow stopped where piping is exposed only to the heat of an ignited spill during the emergency 3. LNG pipelines shall be designed for cool-down with liquid nitrogen where the use of LNG is not possible. 4. All LNG drains should be located within a containment area or piped to a collection system or containment area. 5. LNG lines shall be analyzed for a start-up case where the top of the pipe is 90 degrees F warmer than the bottom of the pipe. The upward bowing of the pipe shall be limited to 1.25 inches. 6. Pipe supports, including any insulation systems used to support pipe whose stability is essential, shall be resistant to or protected against fire exposure, escaping cold liquid, or both if they are subject to such exposure. 7. Pipe supports for cold lines shall be designed to minimize excessive heat transfer, which can result in piping failure by ice formations or embrittlement of supporting steel. If icing up of piping and components is unavoidable, the weight of the accu- mulated ice shall be considered during piping and support design. 8. Valves shall comply with ASME B31.5 [12.5]. 9. Cryogenic valves in liquid cryogenic service shall not be installed in vertical lines. Valves in liquid cryogenic service shall be installed in horizontal lines with the stem in the vertical position or at least 45 degrees vertically from the horizontal centerline of the pipe. 10. All cryogenic valves (except butterfly valves, check valves and globe valves) shall have a body cavity relief to the “safe” side of the valve. All cryogenic valves with a body cavity relief shall be marked on the exterior of the body with a letter “V” and an arrow pointing to the direction of the venting side. 11. Thermal relief valves shall be installed to protect the equipment and piping from over pressuring as a result of ambient heat input to blocked in LNG or other light hydrocarbon liquids. 12. Cryogenic subsea pipeline designs shall be qualified by a certifying agency, acceptable to the Division, in a qualification program that demonstrates that the system has been designed, fabricated and can function as intended with safeguards provided as determined to be necessary.
_**3112F.6 Mechanical components and systems.
Frequently asked questions
Who decides what interceptor I must use?
The Authority Having Jurisdiction (AHJ) must approve the size, type and location of the interceptor; the code requires selecting an interceptor built to a standard listed in Table 1009.1 and submitting that for AHJ approval. § 1009.2, § 1009.1.
Does the CPC give a required cleaning interval?
No — § 1009.6 requires periodic removal to maintain efficient operation but does not set a numeric frequency. The AHJ or local ordinance (or the manufacturer's instructions) typically sets the required interval.
Can I send other wastes (chemicals, mop water, food waste) into the interceptor?
No. § 1009.2 states that, except where specifically permitted, no wastes other than those requiring treatment or separation shall be discharged into an interceptor. Check with the AHJ for allowed exceptions.
If my interceptor is outside the building, does the AHJ still need to approve location?
Yes — the AHJ must approve the location as part of the required approvals for size, type and location under § 1009.2.
What discharge options exist for oil and sand interceptors?
Discharge must be as approved by the AHJ; the AHJ can require connection to a particular system, sampling access, or other restrictions under § 1009.7.
More in California Plumbing Code
- Administration
- Definitions
- General Regulations
- Plumbing Fixtures and Fixture Fittings
- Water Heaters
- Water Supply and Distribution
- Sanitary Drainage (Drain, Waste, and Vent)
- Indirect Wastes
- Vents
- Traps and Interceptors
- Storm Drainage
- Fuel Gas Piping
- Health Care Facilities — Medical Gas and Medical Vacuum Systems
- Alternate Water Sources and Nonpotable Rainwater Catchment Systems
Ask about the CPC
Get cited, plain-English answers on the California Plumbing Code for your project — any code section, any scenario.
Start Free Trial