Water Supply & Backflow

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

• CRC § 602.0 High relevance — show source text

  602.0 Unlawful Connections.

  602.1 Prohibited Installation. No installation of potable water supply piping, or part thereof, shall be made in such a manner that it will be possible for used, unclean, polluted, or contaminated water, mixtures, or substances to enter a portion of such piping from a tank, receptor, equipment, or plumbing fixture by reason of backsiphonage, suction, or other cause, either during normal use and operation thereof, or where such tank, receptor, equipment, or plumbing fixture is flooded or subject to pressure exceeding the operating pressure in the hot or cold water piping. 602.2 Cross-Contamination. No person shall make a connection or allow one to exist between pipes or conduits carrying domestic water supplied by a public or private building supply system, and pipes, conduits, or fixtures containing or carrying water from any other source or containing or carrying water that has been used for any purpose whatsoever, or piping carrying chemicals, liquids, gases, or substances whatsoever, unless there is provided a backflow prevention device approved for the potential hazard and maintained in accordance with this code. Each point of use shall be separately protected where potential cross-contamination of individual units exists.

  602.3 Backflow Prevention. No plumbing fixture, device, or construction shall be installed or maintained, or shall be connected to a domestic water supply, where such installation or connection provides a possibility of polluting such water supply or cross-connection between a distributing system of water for drinking and domestic purposes and water that becomes contaminated by such plumbing fixture, device, or construction unless there is provided a backflow prevention device approved for the potential hazard.

  602.4 Approval by Authority. No water piping supplied by a private water supply system shall be connected to any other source of supply without the approval of the Authority Having Jurisdiction, Health Department, or other department having jurisdiction.

  603.0 Cross-Connection Control.

  603.1 General. Cross-connection control shall be provided in accordance with the provisions of this chapter.

  No person shall install a water-operated equipment or mechanism, or use a water-treating chemical or substance, where it is found that such equipment, mechanism, chemical, or substance causes pollution or contamination of the domestic water supply. Such equipment or mechanism shall be permitted where equipped with an approved backflow prevention device or assembly.

  603.2 Approval of Devices or Assemblies. Before a device or an assembly is installed for the prevention of backflow, it shall have first been approved by the Authority Having Jurisdiction. Devices or assemblies shall be tested in accordance with recognized standards or other standards acceptable to the Authority Having Jurisdiction. Backflow prevention devices and assemblies shall comply with Table 603.2, except for specific applications and provisions as stated in Section 603.5.1 through Section 603.5.22.

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  WATER SUPPLY AND DISTRIBUTION

• CRC § 3.5.2 High relevance — show source text

  pump.

  R309.3.5.2 Required capacity. The water supply shall have the capacity to provide the required design flow rate for sprinklers for a period of time as follows:

  1. Seven minutes for dwelling units one story in height and less than 2,000 square feet (186 m [2] ) in area. For the purpose of determining the area of the dwelling unit, the area of attached garages and attached open carports, porches, balconies and patios shall not be included.
  2. Ten minutes for dwelling units two or more stories in height or equal to or greater than 2,000 square feet (186 m [2] ) in area. For the purpose of determining the area of the dwelling unit, the area of attached garages and attached open carports, porches, balconies and patios shall not be included.

  R309.3.5.2.1 Where a well system, a water supply tank system or a combination thereof is used, the configuration for the system shall be one of the following: 1. The water supply shall serve both domestic and fire sprinkler systems. Any combination of well capacity and tank storage shall be permitted to meet the capacity requirement. 2. A stand-alone tank is permitted if the following conditions are met: 2.1. The pump shall be connected to a 220-volt circuit breaker shared with a common household appliance (e.g., range, oven, dryer), 2.2. The pump shall be a stainless steel 240-volt pump, 2.3. A valve shall be provided to exercise the pump. The discharge of the exercise valve shall be piped to the tank, and

  2.4. A sign shall be provided stating “Valve must be opened monthly for 5 minutes.” 2.5. A means for automatically refilling the tank level so that the tank capacity will meet the required water supply duration in minutes shall be provided.

  R309.3.5.3 Connections to automatic fire sprinkler systems. The potable water supply to automatic fire sprinkler shall be protected against backflow by a double check backflow prevention assembly, a double check fire protection backflow prevention assembly, a reduced pressure principle backflow prevention assembly or a reduced pressure principle fire protection backflow prevention assembly.

  Exception: Where permitted by Section R309.3.1.1, backflow protection for the water supply system shall not be required.

  R309.3.5.3.1 Additives or nonpotable source. Where systems contain chemical additives or antifreeze, or where systems are connected to a nonpotable secondary water supply, the potable water supply shall be protected against backflow by a reduced pressure principle backflow prevention assembly or a reduced pressure principle fire protection backflow prevention assembly. Where chemical additives or antifreeze is added to only a portion of an automatic sprinkler or standpipe system, the reduced pressure principle fire protection backflow preventer shall be permitted to be located so as to isolate that portion of the system.

  R309.3.6 Pipe sizing. The piping to sprinklers shall be sized for the flow required by Section R309.3.4.2. The flow required to supply the plumbing fixtures shall not be required to be added to the sprinkler design flow.

• CRC § 3.5.3 Medium relevance — show source text

  2.4. A sign shall be provided stating “Valve must be opened monthly for 5 minutes.” 2.5. A means for automatically refilling the tank level so that the tank capacity will meet the required water supply duration in minutes shall be provided.

  R309.3.5.3 Connections to automatic fire sprinkler systems. The potable water supply to automatic fire sprinkler shall be protected against backflow by a double check backflow prevention assembly, a double check fire protection backflow prevention assembly, a reduced pressure principle backflow prevention assembly or a reduced pressure principle fire protection backflow prevention assembly.

  Exception: Where permitted by Section R309.3.1.1, backflow protection for the water supply system shall not be required.

  R309.3.5.3.1 Additives or nonpotable source. Where systems contain chemical additives or antifreeze, or where systems are connected to a nonpotable secondary water supply, the potable water supply shall be protected against backflow by a reduced pressure principle backflow prevention assembly or a reduced pressure principle fire protection backflow prevention assembly. Where chemical additives or antifreeze is added to only a portion of an automatic sprinkler or standpipe system, the reduced pressure principle fire protection backflow preventer shall be permitted to be located so as to isolate that portion of the system.

  R309.3.6 Pipe sizing. The piping to sprinklers shall be sized for the flow required by Section R309.3.4.2. The flow required to supply the plumbing fixtures shall not be required to be added to the sprinkler design flow.

  R309.3.6.1 Method of sizing pipe. Piping supplying sprinklers shall be sized using the prescriptive method in Section R309.3.6.2 or by hydraulic calculation in accordance with NFPA 13D. The minimum pipe size from the water supply source to any sprinkler shall be [3] / 4 inch (19 mm) nominal. Threaded adapter fittings at the point where sprinklers are attached to the piping shall be not less than [1] / 2 inch (13 mm) nominal.

  R309.3.6.2 Prescriptive pipe sizing method. Pipe shall be sized by determining the available pressure to offset friction loss in piping and identifying a piping material, diameter and length using the equation in Section R309.3.6.2.1 and the procedure in Section R309.3.6.2.2 .

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  BUILDING PLANNING

  TABLE R309.3.6.2(1)—WATER SERVICE PRESSURE LOSS (PL ) a, b svc	Col2	Col3	Col4	Col5	Col6	Col7	Col8	Col9	Col10	Col11	Col12	Col13
  FLOW RATEc (gpm)	3/4-INCH WATER SERVICE PRESSURE LOSS (psi)	3/4-INCH WATER SERVICE PRESSURE LOSS (psi)	3/4-INCH WATER SERVICE PRESSURE LOSS (psi)	**3/4-INCH

• CRC § 12.3 Medium relevance — show source text

  12.3_|||||||||||||||||||||X|||| |Table 610.3||||X|X|||||||||||||||||||| |610.5||||X|X|||||||||||||||||||| |612.0|||X|||||||||||||||||||||| |612.1|||X|||||||||||||||||||||| |613.0||||||||||X||X|X|X|X|||||||||| |Table 613.1||||||||||X||X|X|X|X|||||||||| |614.0||||||||||X||X|X|X|X|||||||||| |615.0||||||||||X|X|X|X|X|X|||||||||| |616.0||||||||||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.

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  CHAPTER 6

  WATER SUPPLY AND DISTRIBUTION

  601.0 General.

  601.1 Applicability. This chapter shall govern the materials, design, and installation of water supply systems, including methods and devices used for backflow prevention. 601.2 Water Supply and Flushing. Each plumbing fixture shall be provided with an adequate supply of potable running water piped thereto in an approved manner, so arranged as to flush and keep it in a clean and sanitary condition without danger of backflow or cross-connection. Water closets and urinals shall be flushed using an approved flush tank or flushometer valve.

  Exceptions:

  (1) Listed fixtures that do not require water for their operation and are not connected to the water supply.

  (2) Where not deemed necessary for safety and sanitation by the Authority Having Jurisdiction. (3) [HCD 1 & HCD 2] For limited-density owner-built rural dwellings, potable water shall be available to the dwelling site, although such water need not be pressur- ized. Where water is not piped from a well, spring, cistern or other source, there shall be a minimum reserve of 50 gallons (189 L) of potable water available. Where water delivery is pressurized, piping shall be installed in accor- dance with the provisions of this chapter. (4) [HCD 1, HCD 2 & DWR] For all residential occupan- cies, alternate water sources may be allowed as speci- fied in Chapter 15 of this code in addition to potable

  water.

  (5) [BSC-CG & DWR] For non-residential occupancies, alternate water sources may be allowed as specified in Chapter 15 of this code.

• CRC § 603.5.17 Medium relevance — show source text

  603.5.17 Potable Water Outlets and Valves. Potable water outlets, freeze-proof yard hydrants, combination stop-and-waste valves, or other fixtures that incorporate a stop and waste feature that drains into the ground shall not be installed underground. 603.5.18 Pure Water Process Systems. The water supply to a pure water process system, such as dialysis water systems, semiconductor washing systems, and similar process piping systems, shall be protected from backpressure and backsiphonage by a reduced-pressure principle backflow preventer. 603.5.18.1 Dialysis Water Systems. The individual connections of the dialysis related equipment to the dialysis pure water system shall not require additional backflow protection. 603.5.19 Garbage Can Washers. Where garbage can washers are connected to a potable water supply system, the connection shall be protected against backflow in accordance with Table 603.2.

  603.5.20 Plumbing Fixture Fittings. Plumbing fixture fittings with integral backflow protection shall comply with ASME A112.18.1/CSA B125.1. 603.5.21 Swimming Pools, Spas, and Hot Tubs. Potable water supply to swimming pools, spas, and hot tubs shall be protected by an air gap or a reduced pressure principle backflow preventer in accordance with the following:

  (1) The unit is equipped with a submerged fill line.

  (2) The potable water supply is directly connected to the unit circulation system. 603.5.22 Chemical Dispensers. The water supply to chemical dispensers shall be protected against backflow by one of the following:

  (1) The chemical dispenser shall comply with ANSI/CAN/ASSE/IAPMO 1055. Where an installation involves a water source coming from a faucet with an integrated vacuum breaker device, a pressure bleed device conforming to IAPMO PS 104 shall be used to protect the vacuum breaker device.

  (2) Water supply shall be protected by one of the following methods:

  (a) Air gap

  (b) Atmospheric vacuum breaker (AVB)

  (c) Pressure vacuum breaker backflow prevention assembly (PVB)

  (d) Spill-resistant pressure vacuum breaker (SVB)

  (e) Reduced-pressure principle backflow prevention assembly (RP)

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  WATER SUPPLY AND DISTRIBUTION

  604.0 Materials.

  604.1 Pipe, Tube, and Fittings. Pipe, tube, fittings, solvent cement, thread sealants, solders, and flux used in potable water systems intended to supply drinking water shall comply with NSF/ANSI/CAN 61. Where pipe fittings and valves are made from copper alloys containing more than 15 percent zinc by weight and are used in plastic piping systems, they shall be resistant to dezincification and stress corrosion cracking in compliance with NSF/ANSI 14.

  Materials used in the water supply system, except valves and similar devices, shall be of a like material, except where otherwise approved by the Authority Having Jurisdiction.

  Materials for building water piping and building supply piping shall comply with the applicable standards referenced in Table 604.1.

• CRC § 603.5.2 Medium relevance — show source text

  603.5.2 Ballcock. Water closet and urinal tanks shall be equipped with a ballcock. The ballcock shall be installed with the critical level not less than 1 inch (25.4 mm) above the full opening of the overflow pipe. In cases where the ballcock has no hush tube, the bottom of the water supply inlet shall be installed 1 inch (25.4 mm) above the full opening of the overflow pipe.

  603.5.3 Backflow Prevention. Water closet flushometer tanks shall be protected against backflow by an approved backflow prevention assembly, device, or method.

  603.5.4 Heat Exchangers. Heat exchangers used for heat transfer, heat recovery, or solar heating shall protect the potable water system from being contaminated by the

  heat-transfer medium. Single-wall heat exchangers used in indirect-fired water heaters shall meet the requirements of Section 505.4.1. Double-wall heat exchangers shall separate the potable water from the heat-transfer medium by providing a space between the two walls that are vented to the atmosphere. 603.5.5 Water Supply Inlets. Water supply inlets to tanks, vats, sumps, swimming pools, and other receptors shall be protected by one of the following means:

  (1) An approved air gap.

  (2) A listed vacuum breaker installed on the discharge side of the last valve with the critical level not less than 6 inches (152 mm) or in accordance with its listing.

  (3) A backflow preventer suitable for the degree of hazard, installed in accordance with the requirements for that type of device or assembly as set forth in this chapter. 603.5.6 Protection from Lawn Sprinklers and Irri- gation Systems. Potable water supplies to systems having no pumps or connections for pumping equipment, and no chemical injection or provisions for chemical injection, shall be protected from backflow by one of the following devices:

  (1) Atmospheric vacuum breaker (AVB)

  (2) Pressure vacuum breaker backflow prevention assembly (PVB)

  (3) Spill-resistant pressure vacuum breaker (SVB)

  (4) Reduced-pressure principle backflow prevention assembly (RP)

  (5) A valve complying with IAPMO PS 72 603.5.6.1 Systems with Pumps. Where sprinkler and irrigation systems have pumps, connections for pumping equipment, or auxiliary air tanks, or are otherwise capable of creating backpressure, the potable water supply shall be protected by the following type of device where the backflow device is located upstream from the source of backpressure:

  (1) Reduced-pressure principle backflow prevention assembly (RP) 603.5.6.2 Systems with Backflow Devices. Where systems have a backflow device installed downstream from a potable water supply pump or a potable water supply pump connection, the device shall be one of the following:

  (1) Atmospheric vacuum breaker (AVB)

  (2) Pressure vacuum breaker backflow prevention assembly (PVB)

  (3) Spill-resistant pressure vacuum breaker (SVB)

  (4) Reduced-pressure principle backflow prevention assembly (RP) 603.5.6.3 Systems with Chemical Injectors. Where systems include a chemical injector or provisions for chemical injection, the potable water supply shall be protected by a reduced-pressure principle backflow prevention assembly (RP).

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• CRC § 4.33 Medium relevance — show source text

  [MP] BACKFLOW PREVENTER. A backflow prevention assembly, a backflow prevention device or other means or method to prevent backflow into the potable water supply.

  [MP] BACKFLOW PREVENTER, REDUCED-PRESSURE-ZONE TYPE. A backflow-prevention device consisting of two independently acting check valves, internally force loaded to a normally closed position and separated by an intermediate chamber (or zone) in which there is an automatic relief means of venting to atmosphere internally loaded to a normally open position between two tightly closing shutoff valves and with means for testing for tightness of the checks and opening of relief means.

  [MP] BACKPRESSURE. Pressure created by any means in the water distribution system that by being in excess of the pressure in the water supply mains causes a potential backflow condition.

  [MP] BACKPRESSURE, LOW HEAD. A pressure less than or equal to 4.33 psi (29.88 kPa) or the pressure exerted by a 10-foot (3048 mm) column of water.

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  DEFINITIONS

  [MP] BACKSIPHONAGE. The flowing back of used or contaminated water from piping into a potable water-supply pipe due to a negative pressure in such pipe.

  [MP] BACKWATER VALVE. A device installed in a drain or pipe to prevent backflow of sewage.

  [MP] BALANCED VENTILATION SYSTEM. A ventilation system that simultaneously supplies outdoor air to and exhausts air from a space, where the mechanical supply airflow rate and the mechanical exhaust airflow rate are within 10 percent of the average of the two airflow rates.

  [RB] BASEMENT. A story that is not a story above grade plane (see “Story above grade plane”).

  [RB] BASIC WIND SPEED. Three-second gust speed at 33 feet (10 058 mm) above the ground in Exposure C (see Section R301.2.1) as given in Figure R301.2(2).

  [MP] BATHROOM GROUP. A group of fixtures, including or excluding a bidet, consisting of a water closet, lavatory, and bathtub or shower. Such fixtures are located together on the same floor level.

  BEDRIDDEN PERSON. A person, requiring assistance in turning and repositioning in bed, or being unable to independently transfer to and from bed, except in facilities with appropriate and sufficient care staff, mechanical devices if necessary and safety precautions as deter- mined in Title 22 regulations, by the Director of Social Services or his or her designated representative. Persons who are unable to independently transfer to and from bed, but who do not need assistance to turn or reposition in bed, shall be considered nonambulatory.

  The Director of Social Services or his or her designated representative shall make the determination of the bedridden status of persons with developmental disabilities, in consultation with the Director of Developmental Services or his or her designated representative.

  The Director of Social Services or his or her designated representative shall make the determination of the bedridden status of all other persons with disabilities who are not developmentally disabled.

  [MP] BEND. A drainage fitting, designed to provide a change in direction of a drain pipe of less than the angle specified by the amount necessary to establish the desired slope of the line (see “Elbow” and “Sweep”).

• CRC § 601.1 Medium relevance — show source text

  601.1 Applicability. This chapter shall govern the materials, design, and installation of water supply systems, including methods and devices used for backflow prevention. 601.2 Water Supply and Flushing. Each plumbing fixture shall be provided with an adequate supply of potable running water piped thereto in an approved manner, so arranged as to flush and keep it in a clean and sanitary condition without danger of backflow or cross-connection. Water closets and urinals shall be flushed using an approved flush tank or flushometer valve.

  Exceptions:

  (1) Listed fixtures that do not require water for their operation and are not connected to the water supply.

  (2) Where not deemed necessary for safety and sanitation by the Authority Having Jurisdiction. (3) [HCD 1 & HCD 2] For limited-density owner-built rural dwellings, potable water shall be available to the dwelling site, although such water need not be pressur- ized. Where water is not piped from a well, spring, cistern or other source, there shall be a minimum reserve of 50 gallons (189 L) of potable water available. Where water delivery is pressurized, piping shall be installed in accor- dance with the provisions of this chapter. (4) [HCD 1, HCD 2 & DWR] For all residential occupan- cies, alternate water sources may be allowed as speci- fied in Chapter 15 of this code in addition to potable

  water.

  (5) [BSC-CG & DWR] For non-residential occupancies, alternate water sources may be allowed as specified in Chapter 15 of this code.

  (6) [DWR] Where a public agency requires a building to use recycled water to flush water closets and urinals in accordance with California Water Code 13554. 601.2.1 Submeters. [HCD 1] Submeters (or meters) shall be installed to measure potable and reclaimed (recycled) water (hot and cold) that is supplied for the exclusive use of an individual dwelling unit within a newly constructed, multiunit rental residential structure; or for the use of an individual dwelling unit within a newly constructed mixed-use rental residential/commer- cial structure. Submeters (or meters) shall be installed in accordance with this code and the manufacturer’s installation instructions.

  See Water Code Section 517 for definitions of “multiunit residential structure” and “mixed-use resi-

  dential and commercial structure.” See also Civil Code commencing with Section 1954.201.

  Exemptions:

  (1) Long-term health care facilities as defined in Health and Safety Code Section 1418.

  (2) Low-income housing as defined in Health and Safety Code Section 17922.14 (c)(2)(B).

  (3) Residential care facilities for the elderly as defined in Health and Safety Code Section 1569.2 (p)(1).

  (4) Housing at a place of education as defined in Title 24 of the California Code of Regulations, Califor- nia Building Code, Part 2, Section 202.

  (5) Time-share property as defined in Business and Pro- fessions Code Section 11212, Subdivision (aa).

• CRC § 602.4 Medium relevance — show source text

  602.4 Approval by Authority. No water piping supplied by a private water supply system shall be connected to any other source of supply without the approval of the Authority Having Jurisdiction, Health Department, or other department having jurisdiction.

  603.0 Cross-Connection Control.

  603.1 General. Cross-connection control shall be provided in accordance with the provisions of this chapter.

  No person shall install a water-operated equipment or mechanism, or use a water-treating chemical or substance, where it is found that such equipment, mechanism, chemical, or substance causes pollution or contamination of the domestic water supply. Such equipment or mechanism shall be permitted where equipped with an approved backflow prevention device or assembly.

  603.2 Approval of Devices or Assemblies. Before a device or an assembly is installed for the prevention of backflow, it shall have first been approved by the Authority Having Jurisdiction. Devices or assemblies shall be tested in accordance with recognized standards or other standards acceptable to the Authority Having Jurisdiction. Backflow prevention devices and assemblies shall comply with Table 603.2, except for specific applications and provisions as stated in Section 603.5.1 through Section 603.5.22.

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  WATER SUPPLY AND DISTRIBUTION

  Devices or assemblies installed in a potable water supply system for protection against backflow shall be maintained in good working condition by the person or persons having control of such devices or assemblies. Such devices or assemblies shall be tested at the time of installation, repair, or relocation and not less than on an annual schedule thereafter, or more often where required by the Authority Having Jurisdiction. Where found to be defective or inoperative, the device or assembly shall be repaired or replaced. No device or assembly shall be removed from use or relocated or other device or assembly substituted, without the approval of the Authority Having Jurisdiction.

  Testing or maintenance shall be performed by a certified backflow assembly tester or repairer certified in accordance with ASSE/IAPMO/ANSI Series 5000 or any other additional certification approved by the Authority Having Jurisdiction.

  603.3 Backflow Prevention Devices, Assemblies, and Methods. Backflow prevention devices, assemblies, and methods shall comply with Section 603.3.1 through Section 603.3.12.

  603.3.1 Air Gap. The minimum air gap to afford backflow protection shall be in accordance with Table 603.3.1. 603.3.2 Atmospheric Vacuum Breaker (AVB). An atmospheric vacuum breaker consists of a body, a checking member, and an atmospheric port.

  603.3.3 Hose Connection Backflow Preventer. A hose connection backflow preventer consists of two independent check valves with an independent atmospheric vent between and a means of field testing and draining.

  603.3.4 Double Check Valve Backflow Prevention Assembly (DC). A double check valve backflow prevention assembly consists of two independently acting internally loaded check valves, four properly located test cocks, and two isolation valves.

  603.3.5 Pressure Vacuum Breaker Backflow Pre- vention Assembly (PVB). A pressure vacuum breaker backflow prevention assembly consists of a loaded air inlet valve, an internally loaded check valve, two properly located test cocks, and two isolation valves.

• CRC § 207.0 Medium relevance — show source text

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  DEFINITIONS

  as otherwise provided by statute, to have adequate personnel and expertise to carry out the testing of systems, materials, and construction fixtures or appliances. Area Drain. A receptor designed to collect surface or storm water from an open area. Aspirator. A fitting or device supplied with water or other fluid under positive pressure that passes through an integral orifice or constriction, causing a vacuum. Authority Having Jurisdiction. The organization, office, or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, installations, or procedures. The Authority Having Jurisdiction shall be a federal, state, local, or other regional department or an individual such as a plumbing official, mechanical official, labor department official, health department official, building official, or others having statutory authority. In the absence of statutory authority, the Authority Having Jurisdiction may be some other responsible party. This definition shall include the Authority Having Jurisdiction’s duly authorized representative.

  [HCD 1 & HCD 2] “Authority Having Jurisdiction” shall mean “Enforcing Agency” as defined in Section 207.0 of this code.

  204.0 – B –

  Backflow. The flow of water or other liquids, mixtures, or substances into the distributing pipes of a potable supply of water from sources other than its intended source. See Backpressure Backflow and Backsiphonage. Backflow Connection. An arrangement whereby backflow

  can occur.

  Backflow Preventer. A backflow prevention device, an assembly, or another method to prevent backflow into the potable water system. Backpressure Backflow. Backflow due to an increased pressure above the supply pressure, which may be due to pumps, boilers, gravity, or other sources of pressure. Backsiphonage. The flowing back of used, contaminated, or polluted water from a plumbing fixture or vessel into a water supply pipe due to a pressure less than atmospheric in such pipe. See Backflow. Backwater Valve. A device installed in a drainage system to prevent reverse flow.

  Bathroom. A room equipped with a shower, bathtub, or combination bath/shower.

  Bathroom, Half. A room equipped with only a water closet and lavatory. Bathroom Group. Any combination of fixtures, not to exceed one water closet, two lavatories, either one bathtub or one combination bath/shower, and one shower, and may include a bidet and an emergency floor drain. Battery of Fixtures. A group of two or more similar, adjacent fixtures that discharge into a common horizontal waste or soil branch.

  Bedpan Steamer. A fixture that is used to sterilize bedpans by way of steam.

  Body Spray. A shower device for spraying water onto a bather from other than the overhead position.

  Boiler Blowoff. An outlet on a boiler to permit emptying or discharge of sediment.

• CRC § 4.33 Medium relevance — show source text

  [RB] APPROVED AGENCY. An established and recognized organization that is regularly engaged in conducting tests, furnishing inspection services or furnishing product evaluation or certification where such organization has been approved. (HCD 1) “Approved agency” shall mean “Listing agency” and “Testing agency.”

  APPROVED LISTING AGENCY. Any agency approved by the enforcing agency, unless otherwise provided by statute, which is in the busi- ness of listing and labeling and which makes available at least an annual published report of such listings in which specific information is included that the product has been tested to recognized standards and found to comply.

  [RB] APPROVED SOURCE. An independent person, firm or corporation, approved by the building official, who is competent and experienced in the application of engineering principles to materials, methods or systems analyses.

  APPROVED TESTING AGENCY. Any agency which is determined by the enforcing agency, except as otherwise provided by statute, to have adequate personnel and expertise to carry out the testing of systems, materials and construction fixtures or appliances.

  [RB] ASPECT RATIO. The ratio of longest to shortest perpendicular dimensions, or for wall sections, the ratio of height to length.

  [RB] ATTIC. The unfinished space between the ceiling assembly and the roof assembly.

  [RB] ATTIC, HABITABLE. A finished or unfinished habitable space within an attic.

  [MP] BACKFLOW, DRAINAGE. A reversal of flow in the drainage system.

  [MP] BACKFLOW, WATER DISTRIBUTION. The flow of water or other liquids into the potable water-supply piping from any sources other than its intended source. Backsiphonage is one type of backflow.

  [MP] BACKFLOW PREVENTER. A backflow prevention assembly, a backflow prevention device or other means or method to prevent backflow into the potable water supply.

  [MP] BACKFLOW PREVENTER, REDUCED-PRESSURE-ZONE TYPE. A backflow-prevention device consisting of two independently acting check valves, internally force loaded to a normally closed position and separated by an intermediate chamber (or zone) in which there is an automatic relief means of venting to atmosphere internally loaded to a normally open position between two tightly closing shutoff valves and with means for testing for tightness of the checks and opening of relief means.

  [MP] BACKPRESSURE. Pressure created by any means in the water distribution system that by being in excess of the pressure in the water supply mains causes a potential backflow condition.

  [MP] BACKPRESSURE, LOW HEAD. A pressure less than or equal to 4.33 psi (29.88 kPa) or the pressure exerted by a 10-foot (3048 mm) column of water.

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  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  DEFINITIONS

  [MP] BACKSIPHONAGE. The flowing back of used or contaminated water from piping into a potable water-supply pipe due to a negative pressure in such pipe.

  [MP] BACKWATER VALVE. A device installed in a drain or pipe to prevent backflow of sewage.

• CRC § 603.5.6.1 Medium relevance — show source text

  (1) Atmospheric vacuum breaker (AVB)

  (2) Pressure vacuum breaker backflow prevention assembly (PVB)

  (3) Spill-resistant pressure vacuum breaker (SVB)

  (4) Reduced-pressure principle backflow prevention assembly (RP)

  (5) A valve complying with IAPMO PS 72 603.5.6.1 Systems with Pumps. Where sprinkler and irrigation systems have pumps, connections for pumping equipment, or auxiliary air tanks, or are otherwise capable of creating backpressure, the potable water supply shall be protected by the following type of device where the backflow device is located upstream from the source of backpressure:

  (1) Reduced-pressure principle backflow prevention assembly (RP) 603.5.6.2 Systems with Backflow Devices. Where systems have a backflow device installed downstream from a potable water supply pump or a potable water supply pump connection, the device shall be one of the following:

  (1) Atmospheric vacuum breaker (AVB)

  (2) Pressure vacuum breaker backflow prevention assembly (PVB)

  (3) Spill-resistant pressure vacuum breaker (SVB)

  (4) Reduced-pressure principle backflow prevention assembly (RP) 603.5.6.3 Systems with Chemical Injectors. Where systems include a chemical injector or provisions for chemical injection, the potable water supply shall be protected by a reduced-pressure principle backflow prevention assembly (RP).

  2025 CALIFORNIA PLUMBING CODE 141

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  WATER SUPPLY AND DISTRIBUTION

  TABLE 603.2 BACKFLOW PREVENTION DEVICES, ASSEMBLIES, AND METHODS	Col2	Col3	Col4	Col5	Col6	Col7
  DEGREE OF HAZARD	DEGREE OF HAZARD	DEGREE OF HAZARD	DEGREE OF HAZARD	DEGREE OF HAZARD	DEGREE OF HAZARD	DEGREE OF HAZARD
  DEVICE, ASSEMBLY, OR METHOD1	APPLICABLE STANDARDS	POLLUTION (LOW HAZARD)	POLLUTION (LOW HAZARD)	CONTAMINATION (HIGH HAZARD)	CONTAMINATION (HIGH HAZARD)	INSTALLATION2,3
  DEVICE, ASSEMBLY, OR METHOD1	APPLICABLE STANDARDS	BACK- SIPHONAGE	BACK- PRESSURE	BACK- SIPHONAGE	BACK- PRESSURE	BACK- PRESSURE
  Air gap	ASME A112.1.2	X	––	X	––	See Table 603.3.1 in this chapter.
  Air gap fittings for use with plumbing fixtures, appliances, and appurte- nances	ASME A112.1.3	X	––	X	––	Air gap fitting is a device with an internal air gap, and typical installation includes plumbing fixtures, appliances,