CPC · California Plumbing Code

Are direct connections to the potable supply allowed?

You cannot directly tie a rainwater (or other alternate nonpotable) system into your drinking water piping. Make‑up potable water is allowed only in limited cases and only when protected (for example by an air gap sized per the code) and after AHJ‑approved testing.

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Last reviewed: July 6, 2026

What the code requires — plain English

Direct, continuous connections between a rainwater catchment system and the potable water supply are not allowed under § 1602.4. Make‑up potable water may be used only where expressly permitted by the exceptions and then only when the make‑up connection is protected — typically by an air gap as required elsewhere in the code (see § 603.4.4). § 1602.4 is the controlling provision for rainwater catchment systems.

Never tie a rainwater (or other alternate water) system directly into the drinking water piping unless the code’s specific exception and required protective device (for example, an air gap) are provided.

Requirements in detail

Core rule

  • The basic prohibition: no direct connection between a rainwater catchment system and a potable water supply (§ 1602.4) — direct connections are disallowed except as expressly listed in the section’s exceptions.

Allowed workarounds (what the code permits)

  • Makeup water to storage tanks: Potable water (or treated nonpotable/reclaimed water) may be used as makeup for a rainwater storage tank only if the connection is protected by an air gap as required by the code (§ 1602.4, exceptions).
  • Temporary testing connection: A temporary potable connection is allowed solely for the initial cross‑connection test of the rainwater system as described in the code (§ 1602.4, exception; see § 1602.5 for test requirements).

Cross‑connection & backflow rules that apply

  • The general prohibition on installations that permit contaminated water to enter potable piping: § 602.1–§ 602.3 (no installations that create backsiphonage, cross‑contamination, or unprotected cross‑connections).
  • Cross‑connection control requirements and approved protective methods (air gaps, AVB, PVB, DC, RP assemblies) are in Chapter 6 / § 603.0–§ 603.3; an air gap is the preferred physical separation method referenced by the rainwater exceptions.

Air gap specifics (how large must the gap be?)

  • Where the code requires an air gap it references the air‑gap sizing rules. The potable inlet must be separated from the tank/receiving opening by two pipe diameters of the supply inlet, but in no case less than 1 inch (25.4 mm) (see § 603.4.4). Use the larger of the two measurements.

Decision table — when a direct connection is allowed and what protection is required

System / Situation Direct connection allowed? If makeup permitted — required protection Code reference
Rainwater catchment (general) No Makeup allowed only with an air gap (temporary potable connection allowed only for initial test) § 1602.4
Potable rainwater system (Appendix K) No (but makeup allowed) Makeup to storage tank allowed with air gap or reduced‑pressure (RP) backflow preventer per Appendix K K 102.2 (Appendix K)
Reclaimed / recycled water supply systems No Makeup potable water allowed to reclaimed storage only if protected by an air gap; temporary potable connections allowed for initial testing under specified safeguards § 1505.4
Gray water systems No direct connection to potable supply Makeup potable allowed to non‑pressurized storage when protected by an air gap; temporary potable allowed for initial testing § 1503.3
Stormwater treatment systems No direct connection Makeup potable/reclaimed allowed only if connection protected by an air gap S 101.12.1

Testing & AHJ involvement

  • Initial cross‑connection testing is required before system activation; the temporary potable test connection (if used) must be removed after testing and the test performed in the presence of the Authority Having Jurisdiction (AHJ) (§ 1602.5, § 1605.3.2 references).

Exceptions & special cases

  • Exception for makeup water: potable, on‑site treated nonpotable gray water, or reclaimed water may be used as makeup for a rainwater catchment when the connection is protected by an air gap (1602.4 exception).
  • Appendix K (potable rainwater catchment systems) allows makeup with either an air gap or a reduced‑pressure principle backflow preventer (RP) — a notable narrower allowance for systems intended to be potable. K 102.2 clarifies this special case.
  • Temporary potable connections for initial cross‑connection testing are allowed but must follow the test procedure and be removed after testing (§ 1602.4 exception and associated test sections).

Common mistakes

  • Thinking a backflow assembly alone always permits a direct connection: for most rainwater/alternate systems the code requires an air gap (not just a valve or check), except where Appendix K explicitly allows an RP for potable rainwater systems. Always check the specific section for the system type.
  • Using the wrong air‑gap dimension: the required gap is two pipe diameters OR 1 inch, whichever is larger; do not assume 1 inch is always sufficient. § 603.4.4 sets this minimum.
  • Forgetting AHJ approval and testing: Temporary connections for testing and system activation require AHJ presence and formal cross‑connection testing as specified in the code.
  • Mixing terminology: a “closed” direct makeup connection is different from a measured/temporarily allowed test connection — the latter must be removed and cannot be used for normal operation.

Worked example — concrete scenario

Scenario: A homeowner wants to use harvested roof runoff for landscape irrigation. They want an automatic potable make‑up line to top off a 500‑gal rainwater storage tank whenever levels fall.

Step 1 — Direct connection?

  • Under § 1602.4 a direct, continuous connection is not allowed. The homeowner cannot tie the potable line directly into the tank or the catchment distribution piping.

Step 2 — If they want makeup potable water, what protection is needed?

  • The code permits makeup potable water only if the potable inlet to the tank is protected by an air gap (or other allowed protection where the code/appendix permits). Per § 603.4.4 that gap must be two pipe diameters of the potable supply inlet but at least 1 inch. If the supply pipe is 1" diameter, the required air gap = max(2×1" = 2", 1") = 2 inches.

Step 3 — Installation & testing requirements

  • The installer must provide the air gap detail on plans, get AHJ approval, and perform the initial cross‑connection test in the presence of the AHJ before the system goes into service (see § 1602.2 and § 1602.5). The automatic makeup control should be downstream of the air gap so that no pressurized potable piping is directly connected to the nonpotable system.

Result: The system can operate with an automatic make‑up only if the make‑up inlet to the tank is arranged as an air‑gapped inlet sized per the code, the AHJ accepts the design, and required testing is completed.

Related provisions (code sections to read next)

  • § 1602.4 — Connections to potable or reclaimed (recycled) water systems (controlling section for rainwater catchment).
  • § 1602.5 — Initial cross‑connection test (test procedure and AHJ presence).
  • § 603.4.4 — Air gap sizing: two pipe diameters, not less than 1 inch.
  • Chapter 6 / § 603.0–§ 603.3 — Cross‑connection control methods and device approvals.
  • § 602.1–§ 602.3 — Unlawful connections and cross‑contamination prohibitions.
  • § 1503.3 — Gray water — no direct connection to potable systems (with makeup/air gap exceptions).
  • § 1505.4 — Reclaimed (recycled) water — no direct connection to potable systems; makeup only with protection.
  • S 101.12.1 — Stormwater treatment systems — no direct potable connection; makeup allowed with air gap.
  • Appendix K — K 102.2 — Potable rainwater catchment systems: makeup allowed with air gap OR RP backflow preventer (special appendix allowance).

Code references

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

  • CPC § 1503.2.2 High relevance — show source text

    Exception: It is not the intent of this section to require that all gray water must be handled by an irrigation field or disposal field. It is acceptable for excess gray water to be diverted to the building sewer through a diverter valve or overflow drain as permitted in this chapter. 1503.2.2 Diversion. The gray water system shall connect to the sanitary drainage system downstream of fixture traps and vent connections through an approved diverter valve. The diverter valve shall be installed in a readily accessible location and clearly indicate the direction of flow.

    Exception: [HCD 1] A clothes washer system in com- pliance with Section 1503.1.1. 1503.2.3 Backwater Valves. Gray water drains subject to backflow shall be provided with a backwater valve at the point of connection to the building sewer system, so located as to be accessible for inspection and maintenance. 1503.3 Connections to Potable and Reclaimed (Recy- cled) Water Systems. Gray water systems shall have no direct connection to a potable water supply, on-site treated nonpotable gray water supply, or reclaimed (recycled) water sup- ply systems.

    Exceptions:

    (1) Potable water, on-site treated nonpotable gray water, reclaimed (recycled) water , or rainwater is permitted to be used as makeup water for a non-pressurized storage tank provided the connection is protected by an air gap in accordance with this code.

    (2) A potable water supply may be connected temporarily for the initial cross-connection test of the untreated gray- water system as required in Section 1502.3.2. 1503.4 Location. No gray water system or part thereof shall be located on a lot other than the lot that is the site of the building or structure that discharges the gray water, nor shall a gray water system or part thereof be located at a point having less than the minimum distances indicated in Table 1503.4.

    Exception: When there exists a lawfully recorded perpetual and exclusive covenant to an easement appurtenant and right-of- way between adjoining land-owners of two or more contiguous lots to discharge gray water from one lot to an adjoining lot. 1503.5 Plot Plan Submission. No permit for a gray water system shall be issued until a plot plan with data satisfactory to the Authority Having Jurisdiction has been submitted and approved. Exception: [HCD 1] A construction permit shall not be required for a clothes washer system in compliance with Sec- tion 1503.1.1.

    1503.6 Prohibited Location. Where there is insufficient lot area or inappropriate soil conditions for adequate absorption, no gray water system shall be permitted.

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    ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS

    TABLE 1503.4 LOCATION OF GRAY WATER SYSTEM [7]

  • CPC § 1602.2 High relevance — show source text

    ** The installation, construction, alteration, and repair of rainwater catchments systems intended to supply uses such as water closets, urinals, trap primers for floor drains and floor sinks, irrigation, industrial processes, water features, cooling tower makeup and other uses shall be approved by the Authority Having Jurisdiction. Rainwater catchment systems for collecting precipitation from rooftops shall comply with ARCSA/ASPE/ANSI 63. 1602.2 Plumbing Plan Submission. No permit for a rainwater catchment system shall be issued until complete plumbing plans, with data satisfactory to the Authority Having Jurisdiction, have been submitted and approved. 1602.3 System Changes. No changes or connections shall be made to either the rainwater catchment system or the potable water system within a site containing a rainwater catchment system requiring a permit without approval by the Authority Having Jurisdiction. 1602.4 Connections to Potable or Reclaimed (Recy- cled) Water Systems. Rainwater catchment systems shall have no direct connection to a potable water supply or alternate water source system. Exceptions: (1) Potable water, on-site treated nonpotable gray water, or reclaimed (recycled) water is permitted to be used as makeup water for a rainwater catchment system provided the connection is protected by an air gap in accordance with this code.

    (2) A potable water supply may be connected temporarily for the initial cross-connection test of the rainwater catchment system as required in Section 1605.3.2. 1602.5 Initial Cross-Connection Test. Where a portion of a rainwater catchment system is installed within a building, a cross-connection test is required in accordance with Section 1605.3. Before the building is occupied or the system is activated, the installer shall perform the initial cross-connection test in the presence of the Authority Having Jurisdiction and other authorities having jurisdiction. The test shall be ruled successful by the Authority Having Jurisdiction before final approval is granted. 1602.6 Sizing. The design and size of rainwater drains, gutters, conductors, and leaders shall comply with Chapter 11 of this code.

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    NONPOTABLE RAINWATER CATCHMENT SYSTEMS

    1602.7 Rainwater Catchment System Materials. Rain- 1603.3 Rainwater Catchment Collection Surfaces. water catchment system materials shall comply with Section Rainwater shall be collected from roof surfaces or other 1602.7.1 through Section 1602.7.3 . impervious manmade, aboveground collection surfaces. 1602.7.1 Water Supply and Distribution Materi- 1603.3.1 Other Surfaces. Natural precipitation colals. Rainwater catchment water supply and distribution lected from surface water runoff, vehicular parking surmaterials shall comply with the requirements of this code faces, or manmade surfaces at or below grade shall be in for potable water supply and distribution systems unless accordance with the water quality requirements for onotherwise provided for in this section. site treated nonpotable gray water systems in Section

    1506.0.

    1602.7.2 Rainwater Catchment System Drainage Materials. Materials used in rainwater catchment Exception: Collected rainwater or storm water used

  • CPC § 1505.1.2 High relevance — show source text

    1505.1.2 Structures Allowed for Toilet and Urinal Flushing. In accordance with Water Code Section 13553, reclaimed (recycled) water shall be allowed for toilet and urinal flushing in certain structures. These structures include commercial, retail, and office buildings, theaters, auditoriums, condominium projects, schools, hotels, apart-

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    ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS

    ments, barracks, dormitories, jails, prisons, reformatories, and other structures as determined by the State Water Resources Control Board.

    1505.2 Permit. It shall be unlawful for a person to construct, install, alter, or cause to be constructed, installed, or altered a recycled water supply system within a building or on its premises without first obtaining a permit to do such work from the Authority Having Jurisdiction.

    Prior to commencing the issuance of permits for recy- cled water supply systems pursuant to state requirements relating to recycled water, a city, county, city and county or other local agency shall seek consultation with the State Water Resources Control Board, local public health depart- ment and local recycled water purveyor to ensure that state and local public health concerns are addressed in local stan- dards or ordinances, or in issuing permits.

    1505.2.1 Plumbing Plan Submission. No permit for a recycled water supply system shall be issued until complete plumbing plans, with data satisfactory to the Authority Having Jurisdiction, have been submitted and approved.

    1505.3 System Changes. No changes or connections shall be made to either the recycled water supply system or the potable water system within a site containing a recycled water supply system without approval by the Authority Having Jurisdiction.

    1505.4 Connections to Potable or Recycled Water Supply Systems. Recycled water supply systems shall have no direct connection to a potable water supply or alternate water source system.

    Exceptions:

    (1) Potable water is permitted to be used as makeup water for a reclaimed (recycled) water storage tank provided the potable water supply inlet is protected by an air gap in accordance with this code.

    (2) A potable water supply may be connected temporarily for initial testing of the recycled water supply system as provided in Section 1505.14.2.2. Prior to temporarily connecting the potable line to the recycled water supply system for the initial cross-connection test purposes, the potable line must have a reduced-pressure principle backflow preventer installed.

    (3) Reclaimed (recycled) water is permitted to be used as makeup water for an alternate water source system pro- vided the recycled water supply system is protected by an air gap in accordance with this code.

    (4) In order to use potable water as an auxiliary water sup- ply when there is an interruption to the reclaimed (recy- cled) water supply, a changeover device, swivel ell, or other assembly is permitted if the following two condi-

    tions are met:

    (a) The water user maintains ongoing compliance with State Water Resources Control Board’s Cross-Con-

    nection Control Policy Handbook requirements.

  • CPC § 1601.10 High relevance — show source text

    1601.10 Separation Requirements. Underground rainwater catchment service piping shall be separated from the building sewer in accordance with Section 609.2. Treated nonpotable water pipes shall be permitted to be run or laid in the same trench as potable water pipes with a 12 inch (305 mm) minimum vertical and horizontal separation where both pipe materials are approved for use within a building. Where horizontal piping materials do not meet this requirement, the minimum separation shall be increased to 60 inches (1524 mm). The potable water piping shall be installed at an elevation above the treated nonpotable water piping. 1601.11 Abandonment. Rainwater catchment systems that are no longer in use, or fail to be maintained in accordance with Section 1601.5, shall be abandoned. Abandonment shall comply with Section 1601.11.1 and Section 1601.11.2.

    1601.11.1 General. An abandoned system or part thereof covered under the scope of this chapter shall be disconnected from remaining systems, drained, plugged, and capped in an approved manner. 1601.11.2 Underground Tank. An underground water storage tank that has been abandoned or otherwise discontinued from use in a system covered under the scope of this chapter shall be completely drained and filled with earth, sand, gravel, concrete, or other approved material or removed in a manner satisfactory to the Authority Having Jurisdiction. 1601.12 Sizing. Unless otherwise provided for in this chapter, rainwater catchment piping shall be sized in accordance with Chapter 6 for sizing potable water piping.

    1602.0 Nonpotable Rainwater Catchment Systems. 1602.1 General. The installation, construction, alteration, and repair of rainwater catchments systems intended to supply uses such as water closets, urinals, trap primers for floor drains and floor sinks, irrigation, industrial processes, water features, cooling tower makeup and other uses shall be approved by the Authority Having Jurisdiction. Rainwater catchment systems for collecting precipitation from rooftops shall comply with ARCSA/ASPE/ANSI 63. 1602.2 Plumbing Plan Submission. No permit for a rainwater catchment system shall be issued until complete plumbing plans, with data satisfactory to the Authority Having Jurisdiction, have been submitted and approved. 1602.3 System Changes. No changes or connections shall be made to either the rainwater catchment system or the potable water system within a site containing a rainwater catchment system requiring a permit without approval by the Authority Having Jurisdiction. 1602.4 Connections to Potable or Reclaimed (Recy- cled) Water Systems. Rainwater catchment systems shall have no direct connection to a potable water supply or alternate water source system. Exceptions: (1) Potable water, on-site treated nonpotable gray water, or reclaimed (recycled) water is permitted to be used as makeup water for a rainwater catchment system provided the connection is protected by an air gap in accordance with this code.

    (2) A potable water supply may be connected temporarily for the initial cross-connection test of the rainwater catchment system as required in Section 1605.3.2. 1602.5 Initial Cross-Connection Test. Where a portion of a rainwater catchment system is installed within a building, a cross-connection test is required in accordance with Section 1605.3.

  • CPC § 502.0 High relevance — show source text

    APPENDIX E

    E 502.0 Recreational Vehicle Park Potable Water Supply and Distribution. E 502.1 Quality. The supply or supplies of water shall comply with the potable water standards of the state, local health authority or, in the absence thereof, with the Drinking Water Standard of the Federal Environmental Protection Agency. E 502.2 Sources. Water approved by a regulating agency shall be acceptable. Where an approved public water supply system is available, it shall be used. Where the park has its own water supply system, the components of the system shall be approved. A water supply system that is used on a seasonal basis shall be provided with means for draining. E 502.3 Prohibited Connections. The potable water supply shall not be connected to a nonpotable or unapproved water supply, nor be subjected to backflow or backsiphonage. E 502.4 Supply. The water supply system shall be designed and constructed in accordance with the following:

    (1) A minimum of 25 gallons (95 L) per day per site for sites without individual water connections.

    (2) A minimum of 50 gallons (189 L) per day per site for sites with individual water connections.

    (3) A minimum of 50 gallons (189 L) per day per site where water-supplied water closets are provided in restrooms.

    E 502.5 Pressure and Volume. Where water is distributed under pressure to an individual site, the water supply system shall be designed to provide a minimum flow pressure of not less than 20 psi (138 kPa) with a minimum flow of 2 gallons per minute (gpm) (0.1 L/s) at an outlet. The pressure shall not exceed 80 psi (552 kPa).

    E 502.6 Outlets. Water outlets shall be convenient to access and, where not piped to individual recreational vehicle sites, shall not exceed 300 feet (91 m) from a site. Provisions shall be made to prevent accumulation of standing water or the creation of muddy conditions at each water outlet. E 502.7 Storage Tanks. Water storage tanks shall be constructed of impervious materials, protected against contamination, and provided with locked, watertight covers. Overflow or ventilation openings shall be down-facing and provided with a corrosion-resistant screening of not less than number 24 mesh to prevent the entrance of insects and vermin. Water storage tanks shall not have direct connections to sewers.

    E 503.0 Recreational Vehicle Park Water Connec- tions for Individual Recreational Vehicles.

    E 503.1 Location. Where provided, the water connections for potable water to individual recreational vehicle sites shall be located on the left rear half of the site (left side of recreational vehicle) within 4 feet (1219 mm) of the stand. E 503.2 Water Riser Pipe. Each potable water connection shall consist of a water riser pipe that is equipped with a threaded male spigot located not less than 12 inches (305 mm) but not more than 24 inches (610 mm) above grade level for the attachment of a standard water hose. The water riser pipe shall be protected from physical damage in accordance with this code. This connection shall be equipped with a listed antisiphon backflow prevention device.

  • CPC § 102.0 High relevance — show source text

    downspouts, and roof washers.|Every 6 months| |Inspect and clear debris from the roof or other aboveground rainwater collection
    surface.|Every 6 months| |Remove tree branches and vegetation overhanging roof or other aboveground rain-
    water collection surface.|As needed| |Inspect pumps and verify operation.|After initial installation and every 12 months thereafter| |Inspect valves and verify operation.|After initial installation and every 12 months thereafter| |Inspect pressure tanks and verify operation.|After initial installation and every 12 months thereafter| |Clear debris and inspect storage tanks, locking devices, and verify operation.|After initial installation and every 12 months thereafter| |Inspect caution labels and marking.|After initial installation and every 12 months thereafter|

    K 102.0 Connection.

    K 102.1 General. No water piping supplied by a potable rainwater catchment system shall be connected to a source of supply without the approval of the Authority Having Jurisdiction, Health Department, or other department having jurisdiction.

    K 102.2 Connections to Public or Private Potable Water Systems. Potable rainwater catchment systems shall have no direct connection to a public or private potable water supply or alternate water source system. Potable water from a public or private potable water system is permitted to be used as makeup water to the rainwater storage tank provided the public, or private potable water supply connection is protected by an air gap or reduced-pressure principle backflow preventer in accordance with this code. K 102.3 Backflow Prevention. The potable rainwater catchment system shall be protected against backflow in accordance with this code.

    K 103.0 Potable Rainfall Catchment System Materials.

    K 103.1 Collections Surfaces. The collection surface for potable applications shall be constructed of a hard, impervious material and shall be approved for potable water use. Roof coatings, paints, and liners shall comply with NSF Protocol P151. K 103.1.1 Prohibited. Roof paints and coatings with lead, chromium, or zinc shall not be permitted. Wood roofing material and lead flashing shall not be permitted. K 103.2 Rainwater Catchment System Drainage Materials. Materials used in rainwater catchment drainage systems, including gutters, downspouts, conductors, and leaders shall be in accordance with the requirements of this code for storm drainage.

    K 103.3 Storage Tanks. Rainwater storage shall comply with Section K 105.0.

    K 103.4 Water Supply and Distribution Materials. Potable rainwater supply and distribution materials shall comply with the requirements of this code for potable water supply and distribution systems.

    K 104.0 Design and Installation.

    K 104.1 Collection Surfaces. Rainwater shall be collected from a roof or other cleanable aboveground surfaces specifically designed for rainwater catchment. A rainwater catchment system shall not collect rainwater from:

    (1) Vehicular parking surfaces

    (2) Surface water runoff

    (3) Bodies of standing water

    K 104.2 Prohibited Discharges. Overflows, condensate, and bleed-off pipes from roof-mounted equipment and appliances shall not discharge onto roof surfaces that are intended to collect rainwater.

  • CPC § 601.1 High 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).

  • CPC § 101.8 High relevance — show source text

    K 101.8 Material Compatibility. In addition to the requirements of this appendix, potable rainwater catchment systems shall be constructed of materials that are compatible with the type of pipe and fitting materials and water conditions in the system.

    K 101.9 System Controls. Controls for pumps, valves, and other devices that contain mercury that come in contact with the water supply shall not be permitted.

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    APPENDIX K

    TABLE K 101.5.1 MINIMUM POTABLE RAINWATER CATCHMENT SYSTEM TESTING, INSPECTION, AND MAINTENANCE FREQUENCY

    DESCRIPTION MINIMUM FREQUENCY
    Inspect and clean filters and screens, and replace (where necessary). Every 3 months
    Inspect and verify that disinfection, filters and water quality treatment devices and
    systems are operational. Perform water quality tests in accordance with the Author-
    ity Having Jurisdiction.    		 In accordance with the manufacturer’s instructions,
    and the Authority Having Jurisdiction.
    Perform applicable water quality tests to verify compliance with Section K 104.3. Every 3 months
    Perform a water quality test for E. Coli, Total Coliform, and Heterotrophic bacte-
    ria. For a system where 25 different people consume water from the system over a
    60 day period, a water quality test for cryptosporidium shall be performed.    		 After initial installation and every 12 months thereafter,
    or as directed by the Authority Having Jurisdiction.
    Inspect and clear debris from rainwater gutters, downspouts, and roof washers. Every 6 months
    Inspect and clear debris from the roof or other aboveground rainwater collection
    surface.    		 Every 6 months
    Remove tree branches and vegetation overhanging roof or other aboveground rain-
    water collection surface.    		 As needed
    Inspect pumps and verify operation. After initial installation and every 12 months thereafter
    Inspect valves and verify operation. After initial installation and every 12 months thereafter
    Inspect pressure tanks and verify operation. After initial installation and every 12 months thereafter
    Clear debris and inspect storage tanks, locking devices, and verify operation. After initial installation and every 12 months thereafter
    Inspect caution labels and marking. After initial installation and every 12 months thereafter

    K 102.0 Connection.

    K 102.1 General. No water piping supplied by a potable rainwater catchment system shall be connected to a source of supply without the approval of the Authority Having Jurisdiction, Health Department, or other department having jurisdiction.

    K 102.2 Connections to Public or Private Potable Water Systems. Potable rainwater catchment systems shall have no direct connection to a public or private potable water supply or alternate water source system. Potable water from a public or private potable water system is permitted to be used as makeup water to the rainwater storage tank provided the public, or private potable water supply connection is protected by an air gap or reduced-pressure principle backflow preventer in accordance with this code. K 102.3 Backflow Prevention. The potable rainwater catchment system shall be protected against backflow in accordance with this code.

    K 103.0 Potable Rainfall Catchment System Materials.

  • CPC § 3125B.3 High relevance — show source text

    3125B.3 Flow meter. A flow meter shall be provided on each recirculation system accurate to within 10 percent of flow and installed according to the manufacturer’s written instructions with increments in the range of normal flow.

    3125B.4 Basket strainer. A basket strainer shall be provided on the suction side of the recirculation pump. A basket strainer will not be required on pumps connected to vacuum filters where the filter elements are not removed for cleaning.

    3125B.5 Backwash piping. Piping, including necessary valves conforming to Section 3125B.1, shall be provided for each filter vessel or element which requires periodic backwashing.

    3125B.6 Valves. Valves shall not be located in any deck area surrounding a pool. Valves shall be installed on all recirculation, backwash- ing and drain system lines which require shutoff isolation, adjustment or control of the rate of flow. Each valve shall be installed in the equipment area and labeled as to its purpose.

    SECTION 3126B—RECIRCULATION PUMP CAPACITY

    3126B.1 Pool recirculation pumps shall have the following total dynamic head capacities: 1. Pressure diatomaceous earth filters. At least 60 feet (18,288 mm); and

    2. Vacuum diatomaceous earth filters. Twenty inches (508 mm) vacuum on the suction side and 40 feet (12,192 mm) total dynamic head; and 3. Rapid sand filters. At least 45 feet (13,716 mm); and

    4. High rate sand filters. At least 60 feet (18,288 mm); and 5. Cartridge filters. At least 60 feet (18,288 mm).

    3126B.2. Pumps with other total dynamic head capacities shall be permitted provided the turnover times are maintained as required in Section 3124B.

    SECTION 3127B—WATER SUPPLY INLETS

    3127B.1 General. Each pool shall be supplied with potable water by means of a permanently installed pipeline from a public water supply system holding a permit from the California Department of Public Health or from a source approved by the enforcing agent.

    3127B.2 Backflow prevention. There shall be no direct connection between any potable water supply system and the pool or its piping system unless protected by a backflow prevention device in accordance with Chapter 6 of the California Plumbing Code.

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    3127B.3 Makeup water. Automatic makeup water flow controls with a manual override control shall be provided to maintain the proper pool water level.

    SECTION 3128B—FILTERS (ALL TYPES)

    3128B.1 General requirements. All filters, regardless of type, shall be designed and constructed according to the applicable require- ments established by the NSF/ANSI 50-2012 performance standard effective September 2012.

  • CPC § 601.8.1.1 High relevance — show source text

    601.8.1.1 Equipment using potable water shall be so installed as to prevent back-siphonage into the potable water system.

    601.8.1.2 Non-potable water is permitted only in those parts of o ffi cial plants where no edible product is han- dled or prepared, and then only for limited purposes, such as on ammonia condensers not connected with the potable water supply, in vapor lines serving inedi- ble product rendering tanks, in connection with equip- ment used for washing and washing inedible products preparatory to tanking, and in sewer lines for moving heavy solids in sewage. In all cases, non-potable water lines shall be clearly identi fi ed and shall not be cross connected with the potable water supply.

    Exception: Cross connection is permitted if this is necessary for fi re protection, and such connection is of a type with a break to ensure against accidental contamination, and is approved by local authorities or by the Department.

    601.8.2 All pipelines, reservoirs, tanks, cooling towers, and like equipment employed in handling reused water shall be constructed and installed so as to facilitate their cleaning and inspection.

    601.8.3 Hot water for cleaning rooms and equipment shall be delivered under pressure to outlets and shall be of such temperature as to accomplish a thorough cleanup.

    601.8.3.1 An ample supply of water at not less than 180°F (82°C) shall be available when used for san- itizing purposes.

    601.8.4 Pens, alleys, and runways shall have hose con- nections for cleanups purposes.

    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.

  • CPC § 603.4.2 High relevance — show source text

    603.4.2 Testing. The premise owner or responsible person shall have the backflow prevention assembly tested by a certified backflow assembly tester 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. The periodic testing shall be performed in accordance with the procedures referenced in ASSE/IAPMO/ANSI Series 5000 by a tester qualified in accordance with those standards. The field test kit used shall comply with ASSE 1064.

    603.4.3 Access and Clearance. Access and clearance shall be provided for the required testing, maintenance, and repair. Access and clearance shall be in accordance with the manufacturer’s instructions, and not less than 12 inches (305 mm) between the lowest portion of the assembly and grade, floor, or platform. Installations elevated that exceed 5 feet (1524 mm) above the floor or grade shall be provided with a platform capable of supporting a tester or maintenance person.

    603.4.4 Connections. Direct connections between potable water piping and sewer-connected wastes shall not be permitted to exist un der any condition with or without backflow protection. Where potable water is discharged to the drainage system, it shall be by means of an approved air gap of two pipe diameters of the supply

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    WATER SUPPLY AND DISTRIBUTION

    inlet, but in no case shall the gap be less than 1 inch (25.4 mm). Connection shall be permitted to be made to the inlet side of a trap provided that an approved vacuum breaker is installed not less than 6 inches (152 mm), or the distance according to the device’s listing, above the flood-level rim of such trapped fixture, so that at no time will such device be subjected to backpressure.

    603.4.5 Hot Water Backflow Preventers. Backflow preventers for hot water exceeding 110°F (43°C) shall be a type designed to operate at temperatures exceeding 110°F (43°C) without rendering a portion of the assembly inoperative. 603.4.6 Integral Backflow Preventers. Fixtures, appliances, or appurtenances with integral backflow preventers or integral air gaps manufactured as a unit shall be installed in accordance with their listing requirements and the manufacturer’s installation instructions.

    603.4.7 Freeze Protection. In cold climate areas, backflow assemblies and devices shall be protected from freezing with an outdoor enclosure that complies with ASSE 1060 or by a method acceptable to the Authority Having Jurisdiction. 603.4.8 Drain Lines. Drain lines serving backflow devices or assemblies shall be sized in accordance with the discharge rates of the manufacturer’s flow charts of such devices or assemblies.

    603.4.9 Prohibited Locations. Backflow prevention devices with atmospheric vents or ports shall not be installed in pits, underground, or submerged locations. Backflow preventers shall not be located in an area containing fumes that are toxic, poisonous, or corrosive. 603.5 Specific Requirements. Specific requirements for backflow prevention shall comply with Section 603.5.1 through Section 603.5.22. **603.5.1 Atmospheric Vacuum Breaker.

  • CPC § 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

Frequently asked questions

Can I use a reduced‑pressure backflow preventer instead of an air gap for rainwater make‑up?

Generally no for standard (non‑potable) rainwater catchment systems — § 1602.4 requires an air gap for makeup. Appendix K (potable rainwater systems) specifically allows an RP as an alternative for systems intended to be potable; always confirm which part of the code applies to your system.

Is a temporary potable connection ever allowed?

Yes — the code permits a temporary potable connection for the initial cross‑connection test only; the test must be conducted per the code and under AHJ supervision and the temporary connection removed after testing.

How big must the air gap be?

The air gap must be two pipe diameters of the supply inlet, but not less than 1 inch; use the larger dimension. See § 603.4.4.

Who inspects and approves the connection method?

The Authority Having Jurisdiction (AHJ) must review plans, approve system changes or connections, and witness initial cross‑connection testing where required (see § 1602.2, § 1602.5, and related cross‑connection sections).

What if my jurisdiction has local requirements for reclaimed water?

Reclaimed (recycled) water use and cross‑connection control may also be subject to State Water Resources Control Board rules and local purveyor permits; follow § 1505.1 and the State policies in addition to the CPC.

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