CRC · California Residential Code
Prohibited storm‑to‑sanitary connections & drainage testing
You may not connect rain, surface, or subsurface water into a sanitary drainage system unless the local authority approves it (see § 714.2). When water‑testing storm drainage, fill to overflow or the highest opening, use at least a 10‑foot head, hold the water 15 minutes, and inspect for leaks (see § 1107.2.1).
Last reviewed: July 6, 2026
What the code requires — plain English
- § 714.2: No rain, surface, or subsurface water may be connected to or discharged into a sanitary drainage system unless the Authority Having Jurisdiction first approves that connection.
- § 1107.2.1: When you test a newly installed or altered building storm drainage system by water, each tested section must be filled to the point of overflow (or to the highest opening) and hold at least a 10 foot (3048 mm) head of water for not less than 15 minutes before inspection; plastic pipe must not be tested with air.
The single most important rule: do not route rain or ground water into the sanitary sewer — and when you water‑test storm piping, use at least a 10‑foot head and keep it for 15 minutes before checking for leaks. (See § 714.2 and § 1107.2.1.)
Requirements in detail
Prohibition on storm → sanitary connections
- What is prohibited: any connection that conveys rain, surface, or subsurface water into a drainage system intended for sanitary sewage unless expressly approved by the Authority Having Jurisdiction. This is an absolute requirement in the code text. § 714.2 is the controlling provision.
- Why it matters: prohibited connections can overload sanitary sewers, cause sanitary overflows, create public‑health hazards, and violate local sewer authority rules.
Testing storm drainage — the water test
Key dimensions and thresholds to apply when performing a water test under § 1107.2.1:
| Decision element | Required value / action | Code Reference |
|---|---|---|
| Minimum test head for any tested section | 10 foot (3048 mm) of water head (no section tested with less) | § 1107.2.1 |
| Minimum hold time before inspection | 15 minutes with water in place | § 1107.2.1 |
| How to close openings | All openings tightly closed except the highest opening (or highest opening of the section being tested) | § 1107.2.1 |
| Testing whole system vs. sections | Entire system may be tested or tested in sections; when testing successive sections, include at least the upper 10 feet (3048 mm) of the preceding section so every joint (except the uppermost 10 ft of roof drainage) sees a 10 ft head | § 1107.2.1 |
| Plastic piping and air testing | Plastic pipe shall not be tested with air. Use the water test for plastic where applicable. | § 1107.2 (preamble) / § 1107.2.1 |
| Exceptions to testing | Outside leaders and perforated or open‑jointed drain tile are excluded from these tests. | § 1107.2 |
Notes on procedure (from § 1107.2.1): fill the section to overflow (or to the highest opening), keep the water in place at the required head for at least 15 minutes, then inspect for leaks. When testing in sections, overlap the top 10 ft of the previous section so no joint receives less than the 10 ft head (the code allows the very uppermost 10 ft of a roof drainage run to be tested to the flood level of the uppermost roof drain).
Exceptions & special cases
- The prohibition in § 714.2 can be waived only when the Authority Having Jurisdiction gives approval. Any local approval must be documented and coordinate with the sewer agency. § 714.2 requires approval before connecting rain/surface/subsurface water to a sanitary drainage system.
- The water‑test rules do not apply to outside leaders or perforated/open‑jointed drain tile; these are exempt from the standard water/air test requirement in § 1107.2. For plastic piping, do not use air testing — use the water method in § 1107.2.1.
- Where combined sewers exist, the code limits how storm drains are tied into a combined system (see related provisions listed below) — such combinations are tightly regulated and are not an automatic exception to the separation requirement. See § 1101.16.2 for combining rules.
Common mistakes
- Assuming roof leaders or downspouts may be tied into sanitary laterals without permission — they may not unless approved by the AHJ (contrary to § 714.2).
- Testing plastic storm piping with compressed air (this is disallowed by the code). Use the water test per § 1107.2.1.
- Failing to provide the required 10‑foot head when testing sections or not holding the water for 15 minutes before inspection. Inspectors will call leaks if the head/time criteria are not met.
- Not overlapping successive test sections by the upper 10 feet — that can result in joints that never experienced the required test head.
Worked example — applying § 1107.2.1 and § 714.2
Scenario: You install a new building storm drain from roof drains down to a building storm sewer. The run is 30 feet vertically from the highest roof drain opening to the main horizontal connection; the contractor elects to test the run in two sections.
Steps and numbers to meet the code:
- Sectioning: divide the run into two sections so each section is testable — e.g., lower section (bottom to 15 ft up) and upper section (top 15 ft). When testing the upper section you must include at least the upper 10 ft of the lower section in the test so that every joint (except the absolute topmost 10 ft of roof drainage) sees at least a 10‑ft head.
- Apply the water test to the lower section: tightly plug all openings except its highest opening; fill the section until water overflows the highest opening (or to the required head). Ensure the section has at least a 10‑ft head. Keep water in place 15 minutes; inspect for leaks. Pass only if no leaks. § 1107.2.1.
- Test the upper section: plug openings except its highest opening, fill until overflow; make sure the test includes the upper 10 ft of the previously tested lower section so joints are tested under 10 ft head. Hold 15 minutes, inspect. § 1107.2.1.
- Compliance with storm/sanitary separation: do not route any of these leaders or the storm drain into a sanitary sewer or building sanitary drain unless you first obtain AHJ approval per § 714.2. If the local sewer system is combined, follow the combining rules in the code (see related sections).
Related provisions (quick list)
- § 714.2 — Prohibited water discharge: no rain, surface, or subsurface water into drainage systems without AHJ approval.
- § 1107.2.1 — Water test procedure and thresholds for storm drainage testing (10 ft head, 15 minutes).
- § 1107.2 — Methods of testing storm drainage systems; exceptions (outside leaders, perforated/open‑jointed drain tile) and note that plastic pipe shall not be air‑tested.
- § 1101.3 — General prohibition: storm water shall not be drained into sewers intended for sanitary drainage.
- § 1101.16.2 — Combining storm with sanitary only where a combined sewer is used and then only by specified connection (single wye not less than 10 feet (3048 mm) downstream from a soil stack).
If you want, I can:
- Draft a one‑page test procedure checklist (step‑by‑step with places to record head, section lengths, hold time, and inspector sign‑off) that matches § 1107.2.1.
- Produce contractor wording for permit submittals to request AHJ approval under § 714.2 (what to include so approval is more likely).
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 4.2.1 High relevance — show source text
4|X|||X|X|||||X||X|X|X|X|||||||||| |1101.4.2.1||||X||||||||||||||||||||| |1101.4.2.2||||||||||X||X|X|X|X|||||||||| |1101.6_ Exception_||||X|X||||||||||||||||||||
This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.
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CHAPTER 11
STORM DRAINAGE
1101.0 General.
1101.1 Applicability. This chapter shall govern the materials, design, and installation of storm water drainage systems. 1101.2 Where Required. Roofs, paved areas, yards, courts, courtyards, vent shafts, light wells, or similar areas having rainwater, shall be drained into a separate storm sewer system, or into a combined sewer system where a separate storm sewer system is not available, or to some other place of disposal satisfactory to the Authority Having Jurisdiction. In the case of one- and two-family dwellings, storm water shall be permitted to be discharged on flat areas, such as streets or lawns, so long as the storm water shall flow away from the building and away from adjoining property, and shall not create a nuisance. 1101.3 Storm Water Drainage to Sanitary Sewer Pro- hibited. Storm water shall not be drained into sewers intended for sanitary drainage. 1101.4 Material Uses. Pipe, tube, and fittings conveying rainwater shall be of such materials and design as to perform their intended function to the satisfaction of the Authority Having Jurisdiction. Conductors within a vent or shaft shall be of cast-iron, galvanized steel, wrought iron, copper, copper alloy, lead, Schedule 40 ABS DWV, Schedule 40 PVC DWV, stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or other approved materials, and changes in direction shall be in accordance with the requirements of Section 706.0. ABS and PVC DWV piping installations shall be installed in accordance with applicable standards referenced in Chapter 17 and the firestop protection requirements in the California Building Code . Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50, where tested in accordance with ASTM E84 or UL 723. Plastic piping installed in plenums shall be tested in accordance with all requirements of ASTM E84 or UL 723. Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.
CRC § 1101.3 High relevance — show source text
1101.3 Storm Water Drainage to Sanitary Sewer Pro- hibited. Storm water shall not be drained into sewers intended for sanitary drainage. 1101.4 Material Uses. Pipe, tube, and fittings conveying rainwater shall be of such materials and design as to perform their intended function to the satisfaction of the Authority Having Jurisdiction. Conductors within a vent or shaft shall be of cast-iron, galvanized steel, wrought iron, copper, copper alloy, lead, Schedule 40 ABS DWV, Schedule 40 PVC DWV, stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or other approved materials, and changes in direction shall be in accordance with the requirements of Section 706.0. ABS and PVC DWV piping installations shall be installed in accordance with applicable standards referenced in Chapter 17 and the firestop protection requirements in the California Building Code . Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50, where tested in accordance with ASTM E84 or UL 723. Plastic piping installed in plenums shall be tested in accordance with all requirements of ASTM E84 or UL 723. Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.
[HCD 1 & HCD 2] ABS or PVC installations are limited to not more than two stories of areas of residential accommo- dation.
[OSHPD 1, 2, 3, 4 & 5] ABS and PVC installations are not allowed.
1101.4.1 Copper and Copper Alloys. Joints and connections in copper and copper alloy pipe and tube shall be installed in accordance with Section 705.3.
1101.4.2 Conductors. Conductors installed aboveground in buildings shall comply with the applicable standards referenced in Table 701.2 for aboveground drain, waste, and vent pipe. Conductors installed aboveground level shall be of seamless copper water tube, Type K, L, or M; Schedule 40 copper pipe or Schedule
40 copper alloy pipe; Type DWV copper drainage tube; service weight cast-iron soil pipe or hubless cast-iron soil pipe; standard weight galvanized steel pipe; stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or Schedule 40 ABS or Schedule 40 PVC plastic pipe. 1101.4.2.1 [HCD 1] ABS or PVC installations are limited to not more than two stories of areas of res- idential accommodation.
1101.4.2.2 [OSHPD 1, 2, 3, 4 & 5] ABS and PVC installations are not allowed.
CRC § 603.4.4 High relevance — show source text
Prohibited connections . . . . . . . . . . . . . . .603.4.4, 714.2,
714.3, E 502.7
Reclaimed (recycled) water . . . . . . . . . . . . . . . .1505.12 Required . . . . . . . . . . . . . . . . . . . . . . . . . . .709.1, 713.0 Size of building . . . . . . . . . . . . . . . .Table 702.1, 703.2,
Table 703.2, 710.5,
717.0, Table 717.1, C 304.2,
Table C 304.2, C 601.9
Storm water . . . . . . . . . . . . . . . . . . . . .1101.3, 1101.16.2
Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .718.2 Testing of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .723.0
Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .904.1
Water pipe in trench . . . . . . . . . . . . . . . . . .609.2, 720.0 SHALL, DEFINITION . . . . . . . . . . . . . . . . . . . . . . . . . .221.0
SHEET LEAD . . . . . . . . . . . . . . . . . . . . . . . .408.8, 408.8.3,
701.5, 906.6
SHIELDED COUPLINGS . . . . . .221.0, Table 313.3, 705.2.2
SHOCK ARRESTER, DEFINITION . . . . . . . . . . . . . . .221.0
SHORT TURN [1] ⁄ 4 BEND, PROHIBITED . . . . . .310.5, 706.0
SHOULD, DEFINITION . . . . . . . . . . . . . . . . . . . . . . . . .221.0
SHOWERS
Approved standards . . . . . . . . . . . . . . . . . . . . . . .408.1
Control valves . . . . . . . . . . . . . . . . . . . . . . .408.4, 601.2
Discharge, gray water . . . . . . . . . . . . . . . . . .1503.8.2.2
Finished curb or threshold . . . . . . . . . . . . . . . . . . .408.6
Gang . . . . . . . . . . . . . . . . . . . .209.0, 408.4.1, 408.4.2,
L 201.0, L 402.6.1
Mobile home and recreational
CRC § 1101.4.1 Medium relevance — show source text
Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.
[HCD 1 & HCD 2] ABS or PVC installations are limited to not more than two stories of areas of residential accommo- dation.
[OSHPD 1, 2, 3, 4 & 5] ABS and PVC installations are not allowed.
1101.4.1 Copper and Copper Alloys. Joints and connections in copper and copper alloy pipe and tube shall be installed in accordance with Section 705.3.
1101.4.2 Conductors. Conductors installed aboveground in buildings shall comply with the applicable standards referenced in Table 701.2 for aboveground drain, waste, and vent pipe. Conductors installed aboveground level shall be of seamless copper water tube, Type K, L, or M; Schedule 40 copper pipe or Schedule
40 copper alloy pipe; Type DWV copper drainage tube; service weight cast-iron soil pipe or hubless cast-iron soil pipe; standard weight galvanized steel pipe; stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or Schedule 40 ABS or Schedule 40 PVC plastic pipe. 1101.4.2.1 [HCD 1] ABS or PVC installations are limited to not more than two stories of areas of res- idential accommodation.
1101.4.2.2 [OSHPD 1, 2, 3, 4 & 5] ABS and PVC installations are not allowed.
1101.4.3 Leaders. Leaders installed outside shall comply with the applicable standards referenced in Table 701.2 for aboveground drain, waste, and vent pipe; aluminum sheet metal; galvanized steel sheet metal; or copper sheet metal. 1101.4.4 Underground Building Storm Drains. Underground building storm drains shall comply with the applicable standards referenced in Table 701.2 for underground drain, waste, and vent pipe. 1101.4.5 Building Storm Sewers. Building storm sewers shall comply with the applicable standards referenced in Table 701.2 for building sewer pipe. 1101.4.6 Subsoil Drains. Subsoil drains shall be open jointed, perforated, or both and constructed of materials in conformance with Table 1101.4.6.
TABLE 1101.4.6
MATERIALS FOR SUBSOIL DRAINPIPE AND FITTINGS
MATERIAL REFERENCED STANDARD(S)
PEASTM F667
PVCASTM D2729 Vitrified Clay (Extra strength) ASTM C4, ASTM C700 1101.5 Expansion Joints Required. Expansion joints or sleeves shall be provided where warranted by temperature variations or physical conditions. 1101.6 Subsoil Drains. Subsoil drains shall be provided around the perimeter of buildings having basements, cellars, crawl spaces, or floors below grade.
CRC § 8-903.2 Medium relevance — show source text
8-903.2 Residential occupancies.
8-903.2.1 Where toilet facilities are provided, alternative sewage disposal methods may be acceptable if approved by the local health department. In hotels, where private facilities are not provided, water closets at the ratio of one for each 15 rooms may be acceptable.
8-903.2.2 Toilet facilities are not required to be on the same floor or in the same building as sleeping rooms. Water-flush toilets may be located in a building immediately adjacent to the sleeping rooms. When alternative sewage disposal methods are utilized, they shall be located a minimum distance from the sleeping rooms or other locations as approved by the local health department.
8-903.2.3 Kitchen sinks shall be provided in all kitchens. The sink and countertop may be of any smooth nonabsorbent finish which can be maintained in a sanitary condition.
8-903.2.4 Hand washing facilities shall be provided for each dwelling unit and each hotel guest room. A basin and pitcher may be acceptable as adequate hand washing facilities.
8-903.2.5 Hot or cold running water is not required for each plumbing fixture, provided a sufficient amount of water is supplied to permit the fixture’s normal operation.
8-903.2.6 Bathtubs and lavatories with filler spouts less than 1 inch (25.4 mm) above the fixture rim may remain in use, provided there is an acceptable overflow below the rim.
8-903.2.7 Original or salvage water closets, urinals and flushometer valves shall be permitted in qualified historical buildings or properties. Historically accurate reproduction, nonlow-consumption water closets, urinals and flushometer valves shall be permitted except where historically accurate fixtures that comply with the regular code are available.
8-903.3 Materials. New nonhistorical materials shall comply with the regular code requirements. The enforcing agency shall accept alternative materials which do not create a safety hazard where their use is necessary to maintain the historical integrity of the building.
8-903.4 Drainage and vent systems. Plumbing fixtures shall be connected to an adequate drainage and vent system. The enforcing agency may require operational tests for drainage and vent systems which do not comply with applicable requirements of the regular code. Vent terminations may be installed in any location which, in the opinion of the enforcing agency, does not create a safety hazard.
8-903.5 Indirect and special wastes. Indirect and special waste systems shall be installed so that no safety hazard is created. Chemical or industrial liquid wastes which may detrimentally affect the sanitary sewer system shall be pretreated to render them safe prior to discharge.
8-903.6 Traps and interceptors. Traps and interceptors shall comply with the regular code requirements except that the enforcing agency shall accept solutions which do not increase the safety hazard. Properly maintained “S” and drum traps may remain in use.
8-903.7 Joints and connections.
8-903.7.1 Joints and connections in new plumbing systems shall comply with applicable requirements of the regular code.
8-903.7.2 Joints and connections in existing or restored systems may be of any type that does not create a safety hazard.
8-903.8 Water distribution. Plumbing fixtures shall be connected to an adequate water distribution system. The enforcing agency may require operational tests for water distribution systems which do not comply with applicable requirements of the regular code. Prohibited (unlawful) connections and cross connections shall not be permitted.
CPC § 2025 Medium relevance — show source text
An acceptable air supply for combustion and ventilation is necessary for the proper operation of fuel-burning appliances. A shortage of combustion air can result in incomplete combustion and the production of poisonous gases, such as carbon monoxide or appliance overheating. Ventilation air provides cooling for the appliance casing and internal controls. Inadequate ventilation of the space in which an appliance is installed can result in increased surrounding temperatures that stress the appliance itself or other appliances in the vicinity.
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FORMAT OF THE UNIFORM PLUMBING CODE
Chapter 6 Water Supply and Distribution.
Chapter 6 regulates the design, material, and installation of water supply and distribution systems, including residential fire sprinklers. The water supply and distribution system is designed to achieve the correct water pressure and flow rates and avoid cross-connections. For fixtures to perform properly, an acceptable supply of potable water is essential to their operation and use. Cross-connections and backflow are ranked as the highest priority because of the long history of recognized health risks posed by cross-connections, outbreaks, or cases of waterborne disease. Piping materials and components are evaluated for their possible effect on the potable water with which they are in contact. The intent is to control the potential adverse health effects produced by indirect additives, products, and materials that come in contact with potable water. When selecting materials for water supply and distribution systems, consider water pressure, water temperature, compatibility with the water supply, durability, support, and sustainability.
In addition, this chapter regulates the design, location, materials, and installation of multipurpose and stand-alone sprinkler systems that do not include the use of antifreeze. Where systems are installed as a portion of the water distribution system under the requirements of this chapter and are not provided with a fire department connection, backflow protection for the water supply system is not required.
Chapter 7 Sanitary Drainage.
This chapter regulates the design and installation of sanitary drainage systems to ensure they will work as intended. Drainage piping should not be oversized nor undersized, and constructed of approved materials to guard against fouling, deposit of solids, clogging, and with cleanouts so arranged that the pipes may be readily cleaned. The purpose of the sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment to an approved point of disposal, such as a public sanitary system or private sewage disposal system.
The basics of a sanitary drainage system include public and private sewage disposal; selection of materials; installation of the building drain and sewer; joining methods for pipe and fittings; drainage fixture units for sizing the drainage system; sumps and ejectors; vent sizing and length of vents; and testing.
Chapter 8 Indirect Wastes.
Chapter 8 regulates indirect waste connections that are required for plumbing fixtures and plumbing appliances dealing with food preparation, dishwashing, potable liquids, and similar equipment. An indirect connection prevents sewage from backing up into a fixture or appliance, thus providing protection against potential health hazards. The waste pipe discharges through an air gap or air break into a waste receptor or standpipe. The protection in the form of an air gap is necessary when the contamination is a potential health hazard or cross connection with the potable water system. Where there is no possibility of contaminating the potable water (nonpotable discharge), the indirect waste pipe may connect in the form of an air break.
CRC § 714.2 Medium relevance — show source text
714.2 Prohibited Water Discharge. No rain, surface, or subsurface water shall be connected to or discharged into a drainage system unless first approved by the Authority Having Jurisdiction.
714.3 Prohibited Sewer Connection. No cesspool, septic tank, seepage pit, or drain field shall be connected to a public sewer or to a building sewer leading to such public
sewer.
714.4 Commercial Food Waste Disposer. The Authority Having Jurisdiction shall review before approval, the installation of a commercial food waste disposer connecting to a private sewage disposal system.
714.5 Tanks. An approved type, watertight sewage or wastewater holding tank, the contents of which, due to their character, shall be periodically removed and disposed of at some approved off-site location, shall be installed where required by the Authority Having Jurisdiction or the Health Officer to prevent anticipated surface or subsurface contamination or pollution, damage to the public sewer, or other hazardous or nuisance conditions.
715.0 Building Sewer Materials.
715.1 Materials. The building sewer, beginning 2 feet (610 mm) from a building or structure, shall be of such materials as prescribed in this code.
715.2 Joining Methods and Materials. Joining methods and materials shall be as prescribed in this code.
715.3 Existing Sewers. Where permitted by the Authority Having Jurisdiction, trenchless methods of rehabilitation of existing building sewer and building storm sewers shall be installed in accordance with Section 715.3.1 or Section 715.3.2.
715.3.1 Sewer Pipe Lining. For trenchless installation of resin-impregnated flexible tubing to line existing building sewers and building storm sewers installation shall be in accordance with ASTM F1216, ASTM F2561, ASTM F2599, or ASTM F3240.
715.3.2 Sewer Pipe Replacement. For trenchless installation of polyethylene (PE) pipe using the pipe bursting method to replace existing building sewers and building storm sewers materials shall be in accordance with ASTM F714.
716.0 Markings.
716.1 General. Pipe, brick, block, prefabricated septic tanks, prefabricated septic tank or seepage pit covers, or other parts or appurtenances incidental to the installation of building sewers or private sewage disposal systems shall be in accordance with the approval requirements of Chapter 3 of this code.
717.0 Size of Building Sewers. 717.1 General. The minimum size of a building sewer shall be determined on the basis of the total number of fixture units drained by such sewer, in accordance with Table 717.1. No building sewer shall be smaller than the building drain.
For alternate methods of sizing building sewers, see Appendix C.
TABLE 717.1
MAXIMUM/MINIMUM FIXTURE UNIT LOADING
CRC § 721.2 Medium relevance — show source text
Easements for . . . . . . . . . . . . . . . . . . . . . . . . . . . .721.2
Ejectors . . . . . . . . . . . . . . . . . . . . .710.2, 710.3, 710.10 Existing . . . . . . . . . . . . . . . . . . . . .102.4.1, 713.6, 715.3 Grade and support of . . . . . . . . . . . . . . . . .708.0, 718.0 Gray water . . . . . . . . . . . . . . . . . . . . .1503.0 – 1503.9.7 Independent system required . . . . . . . . . . . . . . . . .311.0 Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105.0
Joints and connections . . . . . . . . . . . . . . . . . . . . .705.0
Location . . . . . . . . . . . . . . . . . . . . . .307.0, 312.3, 718.3,
720.0, 721.0, Table 721.1
Materials . . . . . . . . . . . . . . . . . . . . . .701.0, Table 701.2,
715.0, 720.1
Mobile home and
recreational vehicle parks . . . . . . . . .E 301.0, E 504.0 Must be on same lot as building . . . . . . . . .307.1, 721.1 Private sewage disposal systems . . . . . . . .713.0, 714.0
Prohibited connections . . . . . . . . . . . . . . .603.4.4, 714.2,
714.3, E 502.7
Reclaimed (recycled) water . . . . . . . . . . . . . . . .1505.12 Required . . . . . . . . . . . . . . . . . . . . . . . . . . .709.1, 713.0 Size of building . . . . . . . . . . . . . . . .Table 702.1, 703.2,
Table 703.2, 710.5,
717.0, Table 717.1, C 304.2,
Table C 304.2, C 601.9
Storm water . . . . . . . . . . . . . . . . . . . . .1101.3, 1101.16.2
Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .718.2 Testing of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .723.0
Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .904.1
CRC § 1101.16 Medium relevance — show source text
1101.16 Leaders, Conductors, and
Connections . . . . . . . . . . . . . . . . .207
1102.0 Roof Drains . . . . . . . . . . . . . . . . . .207
1102.1 Applications . . . . . . . . . . . . . . . . .207
1102.2 Dome Strainers Required . . . . . . .207
1102.3 Roof Drain Flashings . . . . . . . . . .207
1103.0 Size of Leaders, Conductors,
and Storm Drains . . . . . . . . . . . . .207
1103.1 Vertical Conductors and
Leaders . . . . . . . . . . . . . . . . . . . . .207
1103.2 Size of Horizontal Storm
Drains and Sewers . . . . . . . . . . . .207
1103.3 Size of Roof Gutters . . . . . . . . . . .207
1103.4 Side Walls Draining onto a Roof . . . . . . . . . . . . . . . . . .207
Table 1103.1 Sizing Roof Drains, Leaders, and Vertical Rainwater Piping . . .208
1104.0 Values for Continuous Flow . . . . .208
1104.1 General . . . . . . . . . . . . . . . . . . . . .208
1105.0 Controlled-Flow Roof
Drainage . . . . . . . . . . . . . . . . . . . .208
1105.1 Application . . . . . . . . . . . . . . . . . .208
Table 1105.1(1) Controlled-Flow Maximum Roof Water Depth . . . . . . . . . . . . .209
Table 1105.1(2) Distance of Scupper Bottoms Above Roof . . . . . . . . . . . . . . . . . .209
xxxviii 2025 CALIFORNIA PLUMBING CODE
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TABLE OF CONTENTS
1105.2 Setback Roofs . . . . . . . . . . . . . . .209
1106.0 Engineered Storm Drainage System . . . . . . . . . . . . . . . . . . . . .209
1106.1 General . . . . . . . . . . . . . . . . . . . . .209
1106.2 Siphonic Roof Drainage Systems . . . . . . . . . . . . . . . . . . . .209
1106.3 Siphonic Roof Drains . . . . . . . . . .209
1107.0 Testing . . . . . . . . . . . . . . . . . . . . .209
1107.1 Testing Required . . . . . . . . . . . . .209
1107.2 Methods of Testing Storm Drainage Systems . . . . . . . . . . . .209
Table 1103.2 Sizing of Horizontal Rainwater Piping . . . . . . . . . . . . .210
Table 1103.3 Size of Gutters . . . . . . . . . . . . . . .211
CRC § 1101.1 Medium relevance — show source text
1101.1 Applicability . . . . . . . . . . . . . . . . . .205
1101.2 Where Required . . . . . . . . . . . . . .205
1101.3 Storm Water Drainage to Sanitary Sewer Prohibited . . . . . .205
1101.4 Material Uses . . . . . . . . . . . . . . . .205
Table 1101.4.6 Materials for Subsoil Drainpipe and Fittings . . . . . . . . . . . . . . . . . .205
1101.5 Expansion Joints Required . . . . . .205
1101.6 Subsoil Drains . . . . . . . . . . . . . . .205
1101.7 Building Subdrains . . . . . . . . . . . .206
1101.8 Areaway Drains . . . . . . . . . . . . . .206
1101.9 Window Areaway Drains . . . . . . .206
1101.10 Filling Stations and Motor Vehicle Washing Establishments . . . . . . . . . . . . . . .206
1101.11 Paved Areas . . . . . . . . . . . . . . . . .206
1101.12 Roof Drainage . . . . . . . . . . . . . . .206
1101.13 Cleanouts . . . . . . . . . . . . . . . . . . .207
1101.14 Rainwater Sumps . . . . . . . . . . . . .207
1101.15 Traps on Storm Drains and Leaders . . . . . . . . . . . . . . . . . . . . .207
1101.16 Leaders, Conductors, and
Connections . . . . . . . . . . . . . . . . .207
1102.0 Roof Drains . . . . . . . . . . . . . . . . . .207
1102.1 Applications . . . . . . . . . . . . . . . . .207
1102.2 Dome Strainers Required . . . . . . .207
1102.3 Roof Drain Flashings . . . . . . . . . .207
1103.0 Size of Leaders, Conductors,
and Storm Drains . . . . . . . . . . . . .207
1103.1 Vertical Conductors and
Leaders . . . . . . . . . . . . . . . . . . . . .207
1103.2 Size of Horizontal Storm
Drains and Sewers . . . . . . . . . . . .207
1103.3 Size of Roof Gutters . . . . . . . . . . .207
1103.4 Side Walls Draining onto a Roof . . . . . . . . . . . . . . . . . .207
Table 1103.1 Sizing Roof Drains, Leaders, and Vertical Rainwater Piping . . .208
1104.0 Values for Continuous Flow . . . . .208
1104.1 General . . . . . . . . . . . . . . . . . . . . .208
1105.0 Controlled-Flow Roof
Drainage . . . . . . . . . . . . . . . . . . . .208
CRC § 1015.0 Medium relevance — show source text
1015.0 FOG (Fats, Oils, and Greases) Disposal System . . . . . . . . . . . . . .199
1015.1 Purpose . . . . . . . . . . . . . . . . . . . .199
1015.2 Components, Materials, and Equipment . . . . . . . . . . . . . . . . . .200
1015.3 Sizing and Installation . . . . . . . . .200
1015.4 Performance . . . . . . . . . . . . . . . . .200
1016.0 Sand Interceptors . . . . . . . . . . . . .200
1016.1 Discharge . . . . . . . . . . . . . . . . . . .200
1016.2 Authority Having Jurisdiction . . . .200
1016.3 Construction and Size . . . . . . . . .200
1016.4 Separate Use . . . . . . . . . . . . . . . .200
1017.0 Oil and Flammable Liquid Interceptors . . . . . . . . . . . . . . . . . .200
1017.1 Interceptors Required . . . . . . . . . .200
1017.2 Interceptor Design Alternatives . . .200
1017.3 Interceptor Details . . . . . . . . . . . .200
1017.4 Design of Interceptors . . . . . . . . .200
CHAPTER 11 STORM DRAINAGE . . . . . . . . . .203
1101.0 General . . . . . . . . . . . . . . . . . . . . .205
1101.1 Applicability . . . . . . . . . . . . . . . . . .205
1101.2 Where Required . . . . . . . . . . . . . .205
1101.3 Storm Water Drainage to Sanitary Sewer Prohibited . . . . . .205
1101.4 Material Uses . . . . . . . . . . . . . . . .205
Table 1101.4.6 Materials for Subsoil Drainpipe and Fittings . . . . . . . . . . . . . . . . . .205
1101.5 Expansion Joints Required . . . . . .205
1101.6 Subsoil Drains . . . . . . . . . . . . . . .205
1101.7 Building Subdrains . . . . . . . . . . . .206
1101.8 Areaway Drains . . . . . . . . . . . . . .206
1101.9 Window Areaway Drains . . . . . . .206
1101.10 Filling Stations and Motor Vehicle Washing Establishments . . . . . . . . . . . . . . .206
1101.11 Paved Areas . . . . . . . . . . . . . . . . .206
1101.12 Roof Drainage . . . . . . . . . . . . . . .206
1101.13 Cleanouts . . . . . . . . . . . . . . . . . . .207
1101.14 Rainwater Sumps . . . . . . . . . . . . .207
CRC § 701.2 Medium relevance — show source text
2(2)||||||||||||||||||||||||| |701.2(2)(a)||||X|X|||||||||||||||||||| |701.2(2)(b)||||||||||X||X|X|X|X|||||||||| |Table 702.1_& Footnote 10_||||X|X|||||||||||||||||||| |705.1.2||||X|X|||||||||||||||||||| |705.6.2||||X|X|||||||||||||||||||| |705.9.4||||X|X|||||||||||||||||||| |Table 707.2,_ Footnote 1_||||X|X|||||||||||||||||||| |710.3||||X|X|||||||||||||||||||| |713.4||||X||||||||||||||||||||| |717.2|||||||||||||||||||X|||||| |724.0|||||||||||||||||||X|||||| |725.0|||||||||||||||||||X|||||| |726.0|||||||||||||||||||X|||||| |727.0||||||||||X|||||||||||||||
This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.
2025 CALIFORNIA PLUMBING CODE 163
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164 2025 CALIFORNIA PLUMBING CODE
), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.
CHAPTER 7
SANITARY DRAINAGE
Part I – Drainage Systems.
701.0 General.
701.1 Applicability. This chapter shall govern the materials, design, and installation of sanitary drainage systems and building sewers. 701.2 Drainage Piping. Materials for drainage piping shall be in accordance with one of the referenced standards in Table 701.2 except that:
(1) No galvanized wrought-iron or galvanized steel pipe shall be used underground and shall be kept not less than 6 inches (152 mm) aboveground.
(2) ABS and PVC DWV piping installations shall be installed in accordance with applicable standards referenced in Table 701.2 and the firestop protection require- ments in the California Building Code . Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flamespread index of not more than 25 and a smoke-developed index of not more than 50, where tested in accordance with ASTM E84 or UL 723. Plastic piping installed in plenums shall be tested in accordance with all requirements of ASTM E84 or UL 723. Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.
(a) [HCD 1 & HCD 2] ABS and PVC installations are limited to not more than two stories of areas of res- idential accommodation.
Frequently asked questions
Who is the “Authority Having Jurisdiction” (AHJ) for a prohibited connection approval?
The AHJ is the enforcing official (building official/municipal inspector or delegated sewer authority) for your project; § 714.2 requires their approval before any rain/surface/subsurface water is routed into a drainage system.
Can I test plastic storm drains using compressed air?
No. The code explicitly states plastic pipe shall not be tested with air; use the water test method in § 1107.2.1.
What minimum head and hold time does the water test require?
A minimum 10 foot (3048 mm) head of water and a hold time of not less than 15 minutes before inspection, per § 1107.2.1.
If my city has a combined sewer, can I tie storm leaders into the building sanitary sewer?
Only where a combined sewer is used and only following the combining rules in the code (for example, a single wye connection and specified downstream distance) — coordinate with the AHJ; see § 1101.16.2 for the combining condition.
Are outside leaders subject to the water test?
Outside leaders and perforated or open‑jointed drain tile are excepted from the storm‑system tests in § 1107.2.
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