When must a building be connected to a public sewer?

A building with plumbing fixtures on the premises must connect to an available public or approved private sewer; the building‑sewer requirements and availability rules are specified in §713.0–§713.6 .

What materials and standards apply to sanitary drainage and building sewers?

Materials and fittings for drainage and building sewers must comply with the referenced standards (Table 701.2) and the material‑use rules in §701.2; building sewer materials and joining methods are further addressed in §715.1–§715.3 and related referenced standards .

Can storm water be discharged into the sanitary sewer?

No — storm water drainage must be handled separately and may not be drained into sewers intended for sanitary drainage; see §1101.3 for the prohibition and related storm‑drain rules .

Sanitary Drainage & Building Sewers

Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:

CRC § 713.6 High relevance — show source text
713.6 Lot. On every lot or premises hereafter connected to a public sewer, plumbing, and drainage systems or parts thereof on such lot or premises shall be connected with such public sewer.

713.7 Installation. In cities, counties, or both where the installation of building sewers is under the jurisdiction of a department other than the Authority Having Jurisdiction, the provisions of this code relating to building sewers need not apply.

Exception: Single-family dwellings and buildings or structures accessory thereto, existing and connected to an approved private sewage disposal system prior to the time of connecting the premises to the public sewer shall be permitted, where no hazard, nuisance, or insanitary condition is evidenced, and written permission has been obtained from the Authority Having Jurisdiction, remain connected to such properly maintained private sewage disposal system where there is insufficient grade or fall to permit drainage to the sewer by gravity.

714.0 Damage to Public Sewer or Private Sewage Disposal System.

714.1 Unlawful Practices. It shall be unlawful for a person to deposit, by means whatsoever, into a plumbing fixture, floor drain, interceptor, sump, receptor, or device which is

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SANITARY DRAINAGE

connected to a drainage system, public sewer, private sewer, septic tank, or cesspool, ashes; cinders; solids; rags; flammable, poisonous, or explosive liquids or gases; oils; grease; and whatsoever that is capable of causing damage to the public sewer, private sewer, or private sewage disposal system.

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.
CPC § 2025 High 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.

xiv 2025 CALIFORNIA PLUMBING CODE

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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 § 83.3 High relevance — show source text

FROM STACKS**|MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS| |DIAMETER
OF PIPE
(inches)|SLOPE (inches per foot)|SLOPE (inches per foot)|SLOPE (inches per foot)|SLOPE (inches per foot)| |DIAMETER
OF PIPE
(inches)|1⁄16|1⁄8|1⁄4|1⁄2| |2|–|–|21|26| |21⁄2|–|–|24|31| |3|–|20|422|502| |4|–|180|216|250| |5|–|390|480|575| |6|–|700|840|1000| |8|1400|1600|1920|2300| |10|2500|2900|3500|4200| |12|3900|4600|5600|6700| |15|7000|8300|10 000|12 000|

For SI units: 1 inch = 25 mm, 1 inch per foot = 83.3 mm/m

Notes:

1 On-site sewers that serve more than one building shall be permitted to be sized according to the current standards and specifications of the administrative authority for public sewers.

2 A maximum of two water closets or two bathroom groups, except in single-family dwellings, where a maximum of three water closets or three bathroom groups shall be permitted to be installed.

Col1	TABLE C 304.3 HORIZONTAL FIXTURE BRANCHES AND STACKS	Col3	Col4	Col5
DIAMETER OF PIPE (inches)	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS
DIAMETER OF PIPE (inches)	HORIZONTAL FIXTURE BRANCH1	ONE STACK OF THREE OR FEWER BRANCH INTERVALS	STACKS WITH MORE THAN THREE BRANCH INTERVALS	STACKS WITH MORE THAN THREE BRANCH INTERVALS
DIAMETER OF PIPE (inches)	HORIZONTAL FIXTURE BRANCH1	ONE STACK OF THREE OR FEWER BRANCH INTERVALS	TOTAL FOR STACK	**TOTAL AT ONE

CRC § 1101.1 High 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 § 713.0 High relevance — show source text
Part II – Building Sewers.

713.0 Sewer Required. 713.1 Where Required. A building in which plumbing fixtures are installed and premises having drainage piping thereon shall have a connection to a public or private sewer, except as provided in Section 713.2, and Section 713.4. 713.2 Private Sewage Disposal System. Where no public sewer intended to serve a lot or premises is available in a thoroughfare or right of way abutting such lot or premises, drainage piping from a building or works shall be connected to a private sewage disposal system as approved by the Authority Having Jurisdiction. See Appendix H. 713.3 Public Sewer. Within the limits prescribed by Section 713.4 hereof, the rearrangement or subdivision into smaller parcels of a lot that abuts and is served by a public sewer shall not be deemed cause to permit the construction of a private sewage disposal system, and plumbing or drainage systems on a smaller parcel or parcels shall connect to the public sewer. 713.4 Public Sewer Availability. The public sewer shall be permitted to be considered as not being available where such public sewer or a building or an exterior drainage facility connected thereto is located more than 200 feet (60 960 mm) from a proposed building or exterior drainage facility on a lot or premises that abut and is served by such public sewer.

[HCD 1] For residential occupancies, the public sewer may be considered as not being available by the Authority Having Jurisdiction.

713.5 Permit. No permit shall be issued for the installation, alteration, or repair of a private sewage disposal system, or part thereof, on a lot for which a connection with a public sewer is available.

713.6 Lot. On every lot or premises hereafter connected to a public sewer, plumbing, and drainage systems or parts thereof on such lot or premises shall be connected with such public sewer.

713.7 Installation. In cities, counties, or both where the installation of building sewers is under the jurisdiction of a department other than the Authority Having Jurisdiction, the provisions of this code relating to building sewers need not apply.

Exception: Single-family dwellings and buildings or structures accessory thereto, existing and connected to an approved private sewage disposal system prior to the time of connecting the premises to the public sewer shall be permitted, where no hazard, nuisance, or insanitary condition is evidenced, and written permission has been obtained from the Authority Having Jurisdiction, remain connected to such properly maintained private sewage disposal system where there is insufficient grade or fall to permit drainage to the sewer by gravity.

714.0 Damage to Public Sewer or Private Sewage Disposal System.

714.1 Unlawful Practices. It shall be unlawful for a person to deposit, by means whatsoever, into a plumbing fixture, floor drain, interceptor, sump, receptor, or device which is

2025 CALIFORNIA PLUMBING CODE 175

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SANITARY DRAINAGE

connected to a drainage system, public sewer, private sewer, septic tank, or cesspool, ashes; cinders; solids; rags; flammable, poisonous, or explosive liquids or gases; oils; grease; and whatsoever that is capable of causing damage to the public sewer, private sewer, or private sewage disposal system.
CRC § 1101.16 High relevance — show source text
1101.16 Leaders, Conductors, and Connections. Leaders or conductors shall not be used as soil, waste, or vent pipes nor shall soil, waste, or vent pipes be used as leaders or conductors.

1101.16.1 Protection of Leaders. Leaders installed along alleyways, driveways, or other locations where exposed to damage shall be protected by metal guards, recessed into the wall, or constructed from the ferrous pipe. 1101.16.2 Combining Storm with Sanitary Drainage. The sanitary and storm drainage system of a building shall be entirely separate, except where a combined sewer is used, in which case the building storm drain shall be connected in the same horizontal plane through a single wye fitting to the combined building sewer not less than 10 feet (3048 mm) downstream from a soil stack.

1102.0 Roof Drains.

1102.1 Applications. Roof drains shall be constructed of aluminum, cast-iron, copper alloy of not more than 15 percent zinc, leaded nickel bronze, stainless steel, ABS, PVC, polypropylene, polyethylene, or nylon and shall comply with ASME A112.3.1 or ASME A112.6.4.

1102.2 Dome Strainers Required. Roof drains shall have domed strainers.

Exception: Roof drain strainers for use on sun decks, parking decks, and similar areas that are normally serviced and maintained, shall be permitted to be of the flat surface type. Such roof drain strainers shall be level with the deck.

1102.3 Roof Drain Flashings. The connection between the roof and roof drains that pass through the roof and into the interior of the building shall be made watertight by the use of proper flashing material. 1102.3.1 Lead Flashing. Where lead flashing material is used, it shall be not less than 4 pounds per square foot (lb/ft [2] ) (19 kg/m [2] ). 1102.3.2 Copper Flashing. Where copper flashing material is used, it shall be not less than 12 ounces per square foot (oz/ft [2] ) (3.7 kg/m [2] ).

1103.0 Size of Leaders, Conductors, and Storm Drains.

1103.1 Vertical Conductors and Leaders. Vertical conductors and leaders shall be sized by the maximum projected roof area and Table 1103.1.

1103.2 Size of Horizontal Storm Drains and Sewers. The size of building storm drains, or building storm sewers or their horizontal branches shall be based on the maximum projected roof or paved area to be handled and Table 1103.2.

1103.3 Size of Roof Gutters. The size of semi-circular gutters shall be based on the maximum projected roof area and Table 1103.3.

1103.4 Side Walls Draining onto a Roof. Where vertical walls project above a roof to permit storm water to drain into the roof area below, the adjacent roof area shall be permitted to be computed from Table 1103.1 as follows:

(1) For one wall – add 50 percent of the wall area to the roof area figures.

(2) For two adjacent walls of equal height – add 35 percent of the total wall areas.

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CRC § 83.3 High relevance — show source text

000|12 000|

For SI units: 1 inch = 25 mm, 1 inch per foot = 83.3 mm/m

Notes:

1 On-site sewers that serve more than one building shall be permitted to be sized according to the current standards and specifications of the administrative authority for public sewers.

2 A maximum of two water closets or two bathroom groups, except in single-family dwellings, where a maximum of three water closets or three bathroom groups shall be permitted to be installed.

Col1	TABLE C 304.3 HORIZONTAL FIXTURE BRANCHES AND STACKS	Col3	Col4	Col5
DIAMETER OF PIPE (inches)	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS
DIAMETER OF PIPE (inches)	HORIZONTAL FIXTURE BRANCH1	ONE STACK OF THREE OR FEWER BRANCH INTERVALS	STACKS WITH MORE THAN THREE BRANCH INTERVALS	STACKS WITH MORE THAN THREE BRANCH INTERVALS
DIAMETER OF PIPE (inches)	HORIZONTAL FIXTURE BRANCH1	ONE STACK OF THREE OR FEWER BRANCH INTERVALS	TOTAL FOR STACK	TOTAL AT ONE BRANCH INTERVAL
11⁄2	3	4	8	2
2	6	10	24	6
21⁄2	12	20	42	9
3	202	482	722	202
4	160	240	500	90
5	360	540	1100	200
6	620	960	1900	350
8	1400	2200	3600	600
10	2500	3800	5600	1000
12	3900	6000	8400	1500
15	7000	6000	8400	1500

For SI units: 1 inch = 25 mm

Notes:

1 Does not include branches of the building drain.

2 A maximum of two water closets or bathroom groups within each branch interval or more than six water closets or bathroom groups on the stack.

than the required size for the vent serving the drainage stack. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack.

C 501.0 Vacuum Drainage Systems. C 501.1 General. This section regulates the design and installation provisions for vacuum waste drainage systems. Plans for vacuum waste drainage systems shall be submitted to the Authority Having Jurisdiction for approval and shall be considered an engineered designed system. Such plans shall be prepared by a registered design professional to per

CRC § 4.0 High relevance — show source text

0|4.0| |11⁄2 Bathrooms|8.0|5.5| |2 Bathrooms|10.0|6.5| |21⁄2 Bathrooms|11.0|7.5| |3 Bathrooms|12.0|8.0| |Each Additional1⁄2 Bath|0.5|0.5| |Each Additional Bathroom|1.0|1.0| |Bathroom Group (1.6 GPF Flushometer Valve)|3.0|3.0| |Bathroom Group (3.5 GPF Flushometer Valve)|4.0|4.0|

Notes:

1 A bathroom group, for this table, consists of not more than one water closet, up to two lavatories, and either one bathtub or one shower.

2 A half-bath or powder room, for this table, consists of one water closet and one lavatory.

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APPENDIX C

Col1	TABLE C 304.2 BUILDING DRAINS AND BUILDING SEWERS1	Col3	Col4	Col5
DIAMETER OF PIPE (inches)	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS	MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS FOR SANITARY BUILDING DRAINS AND RUNOUTS FROM STACKS
DIAMETER OF PIPE (inches)	SLOPE (inches per foot)	SLOPE (inches per foot)	SLOPE (inches per foot)	SLOPE (inches per foot)
DIAMETER OF PIPE (inches)	1⁄16	1⁄8	1⁄4	1⁄2
2	–	–	21	26
21⁄2	–	–	24	31
3	–	20	422	502
4	–	180	216	250
5	–	390	480	575
6	–	700	840	1000
8	1400	1600	1920	2300
10	2500	2900	3500	4200
12	3900	4600	5600	6700
15	7000	8300	10 000	12 000

For SI units: 1 inch = 25 mm, 1 inch per foot = 83.3 mm/m

Notes:

1 On-site sewers that serve more than one building shall be permitted to be sized according to the current standards and specifications of the administrative authority for public sewers.

2 A maximum of two water closets or two bathroom groups, except in single-family dwellings, where a maximum of three water closets or three bathroom groups shall be permitted to be installed.

|Col1|TABLE C 304.3 HORIZONTAL FIXTURE

CRC § 701.2 High 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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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.
CPC § 2025 High relevance — show source text
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. This method is often preferred to prevent splashing. In addition, health care facilities and special wastes must be protected from contamination that may result from the connection to the drainage system. The waste must be treated to prevent any damage to the piping or sewage treatment process. Waste receptors are sized and designed to prevent splashing and allow for peak discharge conditions.

Chapter 9 Vents.

Chapter 9 regulates the material, design, and installation of vents. A vent system is a pipe or pipes installed in a drainage system that provide a flow of air to and from the system to ventilate it, provide a circulation of air to eliminate trap siphonage, and reduce back-pressure and vacuum surge. In addition, vents provide the rapid and silent flow of waste without exposing occupants of the building to any sewer gases. Proper installation of vents is crucial, as a telltale sign that there is a problem in the drain and vent system is related to the elevation of the horizontal portion of the venting. Venting is not limited to sanitary drainage systems. Venting methods are applicable to other drainage systems such as those for chemical waste, graywater waste, and clear water waste. Sizing the venting system is directly tied to the design of the drainage system. For example, the velocities in the drainage system and its peak flow rates affect the diameters in the venting system. Where the vertical distance between a fixture outlet and trap is excessive, velocities in the entire drainage system will be greater than those in the vent sizing table. All venting methods in this chapter are categorized as either dry vents or wet vents. Vent stacks, stack vents, branch vents, island vents, relief vents, and individual vents are dry vents. Wet vents (horizontal or vertical), circuit vents, combination drain and vents are versions of “wet venting” in which the vent is wetted by drainage flow.

2025 CALIFORNIA PLUMBING CODE xv
CRC § 701.0 Medium relevance — show source text
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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.

(b) [OSHPD 1, 2, 3, 4 & 5] ABS and PVC installations are not allowed.

(3) No vitrified clay pipe or fittings shall be used aboveground or where pressurized by a pump or ejector. They shall be kept not less than 12 inches (305 mm) belowground.

(4) Copper or copper alloy tube for drainage and vent piping shall have a weight of not less than that of copper or copper alloy drainage tube type DWV.

(5) Stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground.

(6) Cast-iron soil pipe and fittings and the stainless steel couplings used to join these products shall be listed and tested in accordance with standards referenced in Table 701.2. Such pipe and fittings shall be marked with the country of origin, manufacturer’s name or registered trademark as defined in the product standards, the third party certifier’s mark, and the class of the pipe or fitting. 701.3 Drainage Fittings. Materials for drainage fittings shall comply with the applicable standards referenced in Table 701.2 of the same diameter as the piping served, and such fittings shall be compatible with the type of pipe used.

CRC § 1.4 Medium relevance — show source text

340 2025 CALIFORNIA PLUMBING CODE

REFERENCED STANDARDS

TABLE 1701.1 (continued) REFERENCED STANDARDS

STANDARD NUMBER	STANDARD TITLE	APPLICATION	REFERENCED SECTION
ASTM C1540-2020	Standard Specification for Heavy-Duty Shielded Couplings Joining Hubless Cast Iron Soil Pipe and Fittings	Joints	705.2.2
ASTM C1563-2008 (R2021)	Standard Test Method for Gaskets for Use in Connection with Hub and Spigot Cast Iron Soil Pipe and Fittings for Sanitary Drain, Waste, Vent, and Storm Piping Applications	Joints	705.2.2
ASTM C1822-2021	Standard Specification for Insulating Covers on Accessible Lavatory Piping	Miscellaneous	403.3
ASTM D1253-2014	Standard Test Method for Residual Chlorine in Water	Miscellaneous	1506.10.6, 1603.4.1
ASTM D1785-2021a	Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120	Piping	Table 604.1, Table 701.

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