CPC · California Plumbing Code

How are systems abandoned or decommissioned?

If a rainwater catchment system or its buried tank is taken out of service in California, the CPC requires you to disconnect the system, drain it, plug and cap piping, and for underground tanks to drain and either fill with approved material or remove the tank — and you must provide valves and other appurtenances so the system can be deactivated for required cross‑connection testing. See **§ 1601.11**, **§ 1601.11.1**, **§ 1601.11.2**, and **§ 1602.9** for the exact requirements.

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

The California Plumbing Code requires that rainwater catchment systems that are no longer in use (or that fail maintenance) be abandoned in accordance with the code. The general steps are to disconnect, drain, plug, and cap the abandoned portion; underground tanks must be drained and either filled with approved material or removed per the Authority Having Jurisdiction. See § 1601.11, § 1601.11.1, and § 1601.11.2 for the abandonment rules and § 1602.9 for deactivation/drainage provisions related to cross‑connection testing.

The single most important rule: if a rainwater catchment or related underground tank is taken out of service it must be disconnected and made safe — drained, plugged/capped, and (for underground tanks) filled or removed — under the Authority Having Jurisdiction. See § 1601.11, § 1601.11.1, § 1601.11.2.

Requirements in detail

Scope and trigger

  • The abandonment requirements apply to rainwater catchment systems that are no longer in use or not maintained per the code — see § 1601.11.

Basic mandatory actions (general)

  • An abandoned system or part thereof must be:
    • Disconnected from remaining systems,
    • Drained,
    • Plugged, and
    • Capped in an approved manner — see § 1601.11.1.

Underground tanks (specific)

  • An abandoned underground water storage tank must be completely drained and then either:
    • Filled with earth, sand, gravel, concrete, or other approved material; or
    • Removed in a manner satisfactory to the Authority Having Jurisdiction — see § 1601.11.2.

Cross‑connection test / deactivation provisions

  • Systems must be provided with required appurtenances (valves, air/vacuum relief valves, etc.) to allow deactivation or drainage when a cross‑connection test is performed; this is required for rainwater catchment systems per § 1602.9, which references cross‑connection testing procedures.
  • (Related cross‑connection testing procedures set minimum depressurization/test timing; see Section 1605.3 for the testing sequence and minimum durations referenced by § 1602.9.)

Quick reference table

Decision factor / condition Required action or value Code Reference
System taken out of service (rainwater catchment) Abandon system (must comply with abandonment clauses) § 1601.11
Abandoned system (general) Disconnect, drain, plug, cap in an approved manner § 1601.11.1
Abandoned underground tank Completely drain and fill with earth/sand/gravel/concrete or remove per AHJ § 1601.11.2
Deactivation for cross‑connection test Provide valves/air or vacuum relief and other appurtenances to allow deactivation/drainage § 1602.9
Minimum depressurization/test time (cross‑connection sequence) Potable or alternate system depressurized/pressurized timing — not less than 1 hour in many cases (see testing sequence) § 1605.3 / § 1605.3.2 (referenced by § 1602.9)
Exception for no treatment No treatment required for rainwater used exclusively for subsurface or non‑sprinkled surface irrigation when storage is less than 5000 gallons (18,927 L) and certain tank geometry conditions apply § 1602.9 (Exception)

Exceptions & special cases

  • The code includes an explicit exception in § 1602.9: no treatment is required when collected rainwater is used exclusively for subsurface or nonsprinkled surface irrigation, the maximum storage volume is less than 5000 gallons (18,927 L), and the tank is supported directly on grade with a height:diameter (or width) ratio ≤ 2:1. That exception modifies treatment—not the abandonment provisions—so abandoned tanks still must be handled per § 1601.11.2.
  • The Authority Having Jurisdiction (AHJ) retains approval authority over the manner of removal or filling of underground tanks; the code requires filling/ removal to be “satisfactory to the Authority Having Jurisdiction” — § 1601.11.2.

Common mistakes

  • Assuming “out of service” means “do nothing.” The CPC requires active abandonment steps — disconnect, drain, plug and cap — not mere isolation. See § 1601.11.1.
  • Leaving an underground tank in place and empty (but not filled) — the code requires it be filled with approved material or removed; do not leave an empty buried tank. See § 1601.11.2.
  • Failing to provide the required appurtenances (valves, air/vacuum reliefs, etc.) needed for the deactivation/drainage required during cross‑connection testing — § 1602.9 mandates those appurtenances for testing.
  • Ignoring the AHJ — tank removal/fill methods and exception applicability must be acceptable to the AHJ; do not make unilateral decisions without approval. See § 1601.11.2.

Worked example

Scenario: A small commercial site has a buried rainwater storage tank (3,000 gallons) that will no longer be used. The owner wants to “abandon” it in place.

Step-by-step applying the CPC:

  1. Confirm the system is out of service and subject to abandonment per § 1601.11.
  2. Follow the general abandonment actions in § 1601.11.1: disconnect the tank piping from remaining systems, drain the tank, plug and cap exposed piping in an approved manner.
  3. For the buried tank, apply § 1601.11.2: because it is an underground tank, the owner must either completely drain it and fill it with earth, sand, gravel, concrete, or other approved material or remove the tank. The chosen filling or removal method must be acceptable to the AHJ. In practice the owner would submit a plan to the AHJ, specify fill material (e.g., clean sand), and perform filling under inspection.

Notes:

  • Even though the tank is < 5000 gallons (so the 1602.9 treatment exception might apply for use decisions), that exception does not waive the abandonment/fill/remove obligations in § 1601.11.2.

Related provisions

  • § 1601.11 — Abandonment (general trigger and direction).
  • § 1601.11.1 — General abandonment actions: disconnect, drain, plug, cap.
  • § 1601.11.2 — Abandoned underground tank: drain and fill or remove; AHJ approval.
  • § 1602.9 — Deactivation and drainage for cross‑connection test; required appurtenances and exception for small storage volumes.
  • § 1605.3 / § 1605.3.2 — Cross‑connection test procedures and minimum test durations referenced by § 1602.9.

Code references

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

  • 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 § 1502.3.1 Medium relevance — show source text

    (1) Notify the Authority Having Jurisdiction of the cross connection.

    ( 2 ) The alternate water source piping to the building and its premises shall be shutdown at the meter, and the alternate water source riser shall be drained.

    ( 3 ) Potable water piping to the building and its prem- ises shall be shutdown at the meter.

    ( 4 ) The cross-connection shall be uncovered and disconnected.

    ( 5 ) The building and its premises shall be retested in accordance with Section 1502.3.1 and Section

    1502.3.2.

    ( 6 ) The potable water system shall be chlorinated with 50 parts-per-million (ppm) chlorine for 24 hours.

    ( 7 ) The potable water system shall be flushed after 24 hours, and a standard bacteriological test shall be performed. Where test results are acceptable, the potable water system shall be permitted to be recharged. 1502.4 Separation Requirements. Underground alternate water source service piping other than gray water shall be separated from the building sewer in accordance with this code. Pipes carrying treated nonpotable water 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 comply with 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.

    Exception: [DWR] Recycled water supply systems that are within or a part of a building shall comply with Section 1505.12.

    1502.5 Abandonment. Alternate water source systems that are no longer in use or fail to be maintained in accordance with Section 1501.5 shall be abandoned. Abandonment shall comply with Section 1502.5.1 and Section 1502.5.2.

    1502.5.1 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.

    2025 CALIFORNIA PLUMBING CODE 311

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    ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS

    1502.5.2 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. 1502.6 Sizing. Unless otherwise provided for in this chapter, alternate water source piping shall be sized in accordance with Chapter 6 for sizing potable water piping.

  • CPC § 1207.2.2.1 Medium relevance — show source text
    1. Desired or field-determined control set points that are permanently recorded on control drawings at control devices or, for digital control systems, in system programming instructions.
    2. A schedule for inspecting and recalibrating all ESS controls.
    3. A service record log form that lists the schedule for all required servicing and maintenance actions and space for logging such actions that are completed over time and retained on-site.

    The ESS shall be operated and maintained in accordance with the manual and a copy of the manual shall be retained at an approved on-site location.

    1207.2.2.1 Ongoing inspection and testing. Systems that monitor and protect the ESS installation shall be inspected and tested in accordance with the manufacturer’s instructions and the operation and maintenance manual. Inspection and testing records shall be maintained in the operation and maintenance manual.

    1207.2.3 Decommissioning. The code official shall be notified prior to the decommissioning of an ESS. Decommissioning shall be performed in accordance with the decommissioning plan that includes the following:

    1. A narrative description of the activities to be accomplished for removing the ESS from service, and from the facility in which it is located.

    2. A listing of any contingencies for removing an intact operational ESS from service, and for removing an ESS from service that has been damaged by a fire or other event. (Material based on NFPA 855 2023 Ed.)

    1207.3 Equipment. ESS equipment shall be in accordance with Sections 1207.3.1 through 1207.3.9.

    1207.3.1 Energy storage system listings. ESS shall be listed in accordance with UL 9540.

    Exceptions:

    1. Lead-acid and nickel-cadmium battery systems less than 50 VAC, 60 VDC in telecommunications facilities for installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations that are in compliance with NFPA 76.
    2. Lead-acid and nickel-cadmium battery systems that are used for DC power for control of substations and control or safe shutdown of generating stations under the exclusive control of the electric utility, and located outdoors or in building spaces used exclusively for such installations.
    3. Lead-acid battery systems in uninterruptable power supplies listed and labeled in accordance with UL 1778 and utilized for standby power applications.

    (Material based on NFPA 855 2023 Ed.)

    1207.3.2 Equipment listing. Chargers, inverters and energy storage management systems shall be covered as part of the UL 9540 listing or shall be listed separately.

    1207.3.3 Utility interactive systems. Inverters shall be listed and labeled in accordance with UL 1741. Only inverters listed and labeled for utility interactive system use and identified as interactive shall be allowed to operate in parallel with the electric utility power system to supply power to common loads.

    1207.3.4 Energy storage management system. Where required by the ESS listing, an approved energy storage management system that monitors and balances cell voltages, currents and temperatures within the manufacturer’s specifications shall be provided. The system shall disconnect electrical connections to the ESS or otherwise place it in a safe condition if potentially hazardous temperatures or other conditions such as short circuits, over voltage or under voltage are detected. (Material based on NFPA 855 2023 Ed.)

    1207.3.5 Enclosures. Enclosures of ESS shall be of noncombustible construction. (Material based on NFPA 855 2023 Ed.)

  • CPC § 1506.11 Medium relevance — show source text

    1506.11 Valves . . . . . . . . . . . . . . . . . . . . . .323

    1506.12 Signs . . . . . . . . . . . . . . . . . . . . . . .323

    1506.13 Inspection and Testing . . . . . . . . .323

    CHAPTER 16 NONPOTABLE RAINWATER

    CATCHMENT SYSTEMS . . . . . . .325

    1601.0 General . . . . . . . . . . . . . . . . . . . . .327

    1601.1 Applicability . . . . . . . . . . . . . . . . . .327

    1601.2 System Design . . . . . . . . . . . . . . .327

    1601.3 Permit . . . . . . . . . . . . . . . . . . . . . .327

    1601.4 Component Identification . . . . . . .327

    1601.5 Maintenance and Inspection . . . .327

    Table 1601.5 Minimum Alternate Water Source Testing, Inspection, and Maintenance Frequency . . . .327

    1601.6 Operation and Maintenance Manual . . . . . . . . . . . . . . . . . . . . .328

    1601.7 Minimum Water Quality Requirements . . . . . . . . . . . . . . . .328

    1601.8 Material Compatibility . . . . . . . . . .328

    1601.9 System Controls . . . . . . . . . . . . . .328

    1601.10 Separation Requirements . . . . . . .328

    1601.11 Abandonment . . . . . . . . . . . . . . . .328

    1601.12 Sizing . . . . . . . . . . . . . . . . . . . . . .328

    1602.0 Nonpotable Rainwater Catchment Systems . . . . . . . . . . .328

    1602.1 General . . . . . . . . . . . . . . . . . . . . .328

    1602.2 Plumbing Plan Submission . . . . . .328

    1602.3 System Changes . . . . . . . . . . . . .328

    1602.4 Connections to Potable or Reclaimed (Recycled) Water Systems . . . . . . . . . . . . . . .328

    1602.5 Initial Cross-Connection Test . . . .328

    1602.6 Sizing . . . . . . . . . . . . . . . . . . . . . .328

    1602.7 Rainwater Catchment System Materials . . . . . . . . . . . . . . . . . . . .329

    1602.8 Rainwater Catchment System Color and Marking Information . . .329

    1602.9 Deactivation and Drainage for Cross-Connection Test . . . . . . . . .329

    1603.0 Design and Installation . . . . . . . . .329

    1603.1 Rainwater Catchment Systems . . .329

    1603.2 Outside Hose Bibbs . . . . . . . . . . .329

    1603.3 Rainwater Catchment

    Collection Surfaces . . . . . . . . . . . .329

    1603.4 Minimum Water Quality . . . . . . . .329

  • CPC § 1207.2.1.1 Medium relevance — show source text

    (Material based on NFPA 855 2023 Ed.)

    1207.2.1.1 Initial acceptance testing. During the commissioning process an ESS shall be evaluated for proper operation in accordance with the manufacturer’s instructions and the commissioning plan prior to final approval.

    12-12 2025 CALIFORNIA FIRE CODE

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

    ENERGY SYSTEMS

    1207.2.1.2 Commissioning report. A report describing the results of the system commissioning, including the results of the initial acceptance testing required in Section 1207.2.1.1, shall be provided to the fire code official prior to final inspection and approval and maintained at an approved on-site location. (Material based on NFPA 855 2023 Ed.)

    1207.2.2 Operation and maintenance. An operation and maintenance manual shall be provided to both the ESS owner or their authorized agent and the ESS operator before the ESS is put into operation and shall include the following:

    1. Manufacturer’s operation manuals and maintenance manuals for the entire ESS, or for each component of the system requiring maintenance, that clearly identify the required routine maintenance actions.
    2. Name, address and phone number of a service agency that has been contracted to service the ESS and its associated safety systems.
    3. Maintenance and calibration information, including wiring diagrams, control drawings, schematics, system programming instructions and control sequence descriptions, for all energy storage control systems.
    4. Desired or field-determined control set points that are permanently recorded on control drawings at control devices or, for digital control systems, in system programming instructions.
    5. A schedule for inspecting and recalibrating all ESS controls.
    6. A service record log form that lists the schedule for all required servicing and maintenance actions and space for logging such actions that are completed over time and retained on-site.

    The ESS shall be operated and maintained in accordance with the manual and a copy of the manual shall be retained at an approved on-site location.

    1207.2.2.1 Ongoing inspection and testing. Systems that monitor and protect the ESS installation shall be inspected and tested in accordance with the manufacturer’s instructions and the operation and maintenance manual. Inspection and testing records shall be maintained in the operation and maintenance manual.

    1207.2.3 Decommissioning. The code official shall be notified prior to the decommissioning of an ESS. Decommissioning shall be performed in accordance with the decommissioning plan that includes the following:

    1. A narrative description of the activities to be accomplished for removing the ESS from service, and from the facility in which it is located.

    2. A listing of any contingencies for removing an intact operational ESS from service, and for removing an ESS from service that has been damaged by a fire or other event. (Material based on NFPA 855 2023 Ed.)

    1207.3 Equipment. ESS equipment shall be in accordance with Sections 1207.3.1 through 1207.3.9.

    1207.3.1 Energy storage system listings. ESS shall be listed in accordance with UL 9540.

  • CPC § 1601.11 Medium relevance — show source text

    1601.11 Abandonment . . . . . . . . . . . . . . . .328

    1601.12 Sizing . . . . . . . . . . . . . . . . . . . . . .328

    1602.0 Nonpotable Rainwater Catchment Systems . . . . . . . . . . .328

    1602.1 General . . . . . . . . . . . . . . . . . . . . .328

    1602.2 Plumbing Plan Submission . . . . . .328

    1602.3 System Changes . . . . . . . . . . . . .328

    1602.4 Connections to Potable or Reclaimed (Recycled) Water Systems . . . . . . . . . . . . . . .328

    1602.5 Initial Cross-Connection Test . . . .328

    1602.6 Sizing . . . . . . . . . . . . . . . . . . . . . .328

    1602.7 Rainwater Catchment System Materials . . . . . . . . . . . . . . . . . . . .329

    1602.8 Rainwater Catchment System Color and Marking Information . . .329

    1602.9 Deactivation and Drainage for Cross-Connection Test . . . . . . . . .329

    1603.0 Design and Installation . . . . . . . . .329

    1603.1 Rainwater Catchment Systems . . .329

    1603.2 Outside Hose Bibbs . . . . . . . . . . .329

    1603.3 Rainwater Catchment

    Collection Surfaces . . . . . . . . . . . .329

    1603.4 Minimum Water Quality . . . . . . . .329

    1603.5 Rainwater Storage Tanks . . . . . . .329

    1603.6 Location . . . . . . . . . . . . . . . . . . . .329

    1603.7 Above Grade . . . . . . . . . . . . . . . .329

    1603.8 Below Grade . . . . . . . . . . . . . . . . .329

    Table 1603.4 Minimum Water Quality . . . . . . . .330

    1603.9 Drainage and Overflow . . . . . . . . .330

    1603.10 Opening and Access Protection . . .330

    1603.11 Marking . . . . . . . . . . . . . . . . . . . . .330

    1603.12 Storage Tank Venting . . . . . . . . . .330

    1603.13 Pumps . . . . . . . . . . . . . . . . . . . . .330

    1603.14 Roof Drains . . . . . . . . . . . . . . . . . .331

    1603.15 Water Quality Devices and Equipment . . . . . . . . . . . . . . . . . .331

    1603.16 Freeze Protection . . . . . . . . . . . . .331

    1603.17 Debris Removal . . . . . . . . . . . . . .331

    1603.18 Required Filters . . . . . . . . . . . . . .331

    2025 CALIFORNIA PLUMBING CODE xlv

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  • CPC § 1505.12. Medium relevance — show source text

    Where horizontal piping materials do not comply with 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.

    Exception: [DWR] Recycled water supply systems that are within or a part of a building shall comply with Section 1505.12.

    1502.5 Abandonment. Alternate water source systems that are no longer in use or fail to be maintained in accordance with Section 1501.5 shall be abandoned. Abandonment shall comply with Section 1502.5.1 and Section 1502.5.2.

    1502.5.1 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.

    2025 CALIFORNIA PLUMBING CODE 311

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS

    1502.5.2 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. 1502.6 Sizing. Unless otherwise provided for in this chapter, alternate water source piping shall be sized in accordance with Chapter 6 for sizing potable water piping.

    1503.0 Gray Water Systems. [BSC-CG] Gray water sys- tems shall be verified in accordance with the California Green Building Standards Code (CALGreen), Chapter 5, Division 5.3. 1503.1 General. The provisions of this section shall apply to the construction, alteration, and repair of gray water systems. A city, county, or city and county or other local government may adopt, after a public hearing and enactment of an ordinance or resolution, building standards that are more restrictive than the gray water building standards adopted in this code. For addi- tional information, see Health and Safety Code Section 18941.7.

    (A) All gray water systems shall be designed with a diverter valve to allow the user to direct the flow to the building sewer and either the irrigation field or disposal field, whichever is used. The means of changing the direction flow of the gray water shall be clearly labeled and readily accessible to the user.

    (B) Water used to wash diapers or similarly soiled or infec- tious garments or other prohibited contents shall be diverted by the user to the building sewer.

    (C) Gray water shall not be used in spray irrigation, allowed to pond or runoff and shall not be discharged directly into or reach any storm sewer system or any surface body of water.

    (D) Human contact with gray water or the soil irrigated by gray water shall be minimized and avoided, except as required to maintain the gray water system. The dis- charge point of any gray water subsoil irrigation or sub- surface irrigation field shall be covered by at least two (2) inches (51 mm) of mulch, rock, or soil, or a solid shield to minimize the possibility of human contact.

  • CPC § 1708.1 Medium relevance — show source text

    1708.1 General. . . . . . . . . . . . . . . . . . . . . 352

    1708.2 Operation and Maintenance Manual . . . . . . . . . . . . . . . . . . . . . 352

    1708.3 Labeling and Marking . . . . . . . . . . 352

    1708.4 Documentation . . . . . . . . . . . . . . . 352

    1708.5 Maintenance . . . . . . . . . . . . . . . . . 352

    1708.6 Records . . . . . . . . . . . . . . . . . . . . 352

    1708.7 System Start-Up . . . . . . . . . . . . . . 352

    1708.8 Contaminants . . . . . . . . . . . . . . . . 352

    1709.0 Decommissioning and Abandonment . . . . . . . . . . . . . . . . 352

    1709.1 General. . . . . . . . . . . . . . . . . . . . . 352

    Part II Closed-Loop Systems . . . . . . . . 352

    1710.0 General. . . . . . . . . . . . . . . . . . . . . 352

    1710.1 Applicability. . . . . . . . . . . . . . . . . . 352

    1710.2 Piping and Tubing. . . . . . . . . . . . . 352

    1710.3 Borehole Piping and Tubing . . . . . 352

    1710.4 Underground Fittings . . . . . . . . . . 352

    1710.5 Verification . . . . . . . . . . . . . . . . . . 353

    1710.6 Vertical Bores . . . . . . . . . . . . . . . . 353

    1711.0 Ground-Heat Exchanger Testing . . . . . . . . . . . . . . . . . . . . . 353

    1711.1 Testing . . . . . . . . . . . . . . . . . . . . . 353

    1711.2 Individual Loop Pressure Testing . . . . . . . . . . . . . . . . . . . . . 353

    1711.3 Field Pressure Testing – Final . . . 353

    1711.4 Field Flow Testing – Final. . . . . . . 353

    Part III Open-Loop Systems . . . . . . . . . . 353

    1712.0 General. . . . . . . . . . . . . . . . . . . . . 353

    1712.1 Applicability. . . . . . . . . . . . . . . . . . 353

    1712.2 Test Wells. . . . . . . . . . . . . . . . . . . 353

    1712.3 Installation of Water Wells . . . . . . 354

    1712.4 Setbacks. . . . . . . . . . . . . . . . . . . . 354

    1713.0 Open Ground Water Systems . . . 354

    1713.1 General. . . . . . . . . . . . . . . . . . . . . 354

  • CPC § 1708.2 Medium relevance — show source text

    (6) Ground-heat exchanger and building piping, valves, and operating controls, shall be set, adjusted, and operating as required.

    (7) The system shall be labeled at the loop charging valves with a permanent-type label, indicating the type of heat transfer fluid used. Where antifreeze is used, the labels shall indicate the antifreeze type and concentration.

    (8) Supply and return lines, as well as associated isolation valves from individual boreholes or water wells, shall be identified and tagged.

    (9) Supply and return lines on submerged systems shall be identified in an approved manner, at the point of entry to a surface water resource.

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    1708.2 Operation and Maintenance Manual. An operation and maintenance manual for the geothermal system shall be provided to the owner. The manual shall include information on required testing and maintenance of the system. Training shall be provided on the system’s operation, maintenance requirements, and on the content of the operation and maintenance manual. The operation and maintenance manual shall contain a layout of the ground-heat exchanger and building loop.

    1708.3 Labeling and Marking. Ground source heat pump ground-loop system piping shall be marked with tape, metal tags, or other methods where it enters a building. The marking shall indicate the following words: “GROUND SOURCE HEAT PUMP-LOOP SYSTEM.” The marking shall indicate antifreeze used in the system by name and concentration.

    1708.4 Documentation. The ground source heat pump system as-built installation drawings and instructions shall be provided to the building owner or designated agent.

    1708.5 Maintenance. The periodic maintenance required, in accordance with the design requirements, shall be provided and be made available to the owner or designated agent.

    1708.6 Records. The ground source heat pump system construction documents shall be provided to the owner.

    1708.7 System Start-Up. System start-up shall be in accordance with ANSI/ CSA/IGSHPA C448 and Section 1708.0.

    1708.8 Contaminants. Particulate contaminants shall be removed from the indoor piping system prior to initial start up.

    1709.0 Decommissioning and Abandonment. 1709.1 General. Decommissioning of geothermal systems shall comply with ANSI/ CSA/IGSHPA C448. Prior to the abandonment or decommissioning of geothermal systems, the owner shall obtain the necessary permits from the Authority Having Jurisdiction.

    Part II – Closed-Loop Systems.

    1710.0 General.

    1710.1 Applicability. Part II of this chapter shall apply to geothermal closed-loop systems such as, but not limited to, building systems coupled with a closed-loop system using water-based fluid as a heat transfer medium.

    1710.2 Piping and Tubing. Piping and tubing for closedloop systems shall be in accordance Section 1703.2 and Table 1703.2.

    1710.3 Borehole Piping and Tubing. Borehole piping or tubing for vertical and horizontally drilled closed-loop systems shall have a minimum wall thickness equal to SDR-11 and shall have a minimum pressure rating of not less than 160 psi (1103 kPa) at 73°F (23°C).

  • CPC § 1207.2.1. Medium relevance — show source text

    A decommissioning plan for removing the ESS from service, and from the facility in which it is located. The plan shall include details on providing a safe, orderly shutdown of energy storage and safety systems with notification to the code officials prior to the actual decommissioning of the system. The decommissioning plan shall include contingencies for removing an intact operational ESS from service, and for removing an ESS from service that has been damaged by a fire or other event.

    Exceptions:

    1. Commissioning shall not be required for lead-acid and nickel-cadmium battery systems at facilities under the exclusive control of communications utilities that comply with NFPA 76 and operate at less than 50 VAC and 60 VDC. A decommissioning plan shall be provided and maintained where required by the fire code official.
    2. Lead-acid and nickel-cadmium battery systems less than 50 VAC, 60 VDC that are in telecommunications facilities for installations of communications equipment under the exclusive control of communications utilities, and are located outdoors or in building spaces or walk-in units used exclusively for such installations that are in compliance with NFPA 76, shall be permitted to have a commissioning plan in compliance with recognized industry practices in lieu of complying with Section 1207.2.1.
    3. Lead-acid and nickel-cadmium battery systems that are used for DC power for control of substations and control or safe shutdown of generating stations under the exclusive control of the electric utilities, and are located in building spaces or walk-in units used exclusively for such installations, shall be permitted to have a commissioning plan in compliance with applicable governmental laws and regulations in lieu of developing a commissioning plan in accordance with Section 1207.2.1. (Material based on NFPA 855 2023 Ed.)

    1207.2.1.1 Initial acceptance testing. During the commissioning process an ESS shall be evaluated for proper operation in accordance with the manufacturer’s instructions and the commissioning plan prior to final approval.

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    ENERGY SYSTEMS

    1207.2.1.2 Commissioning report. A report describing the results of the system commissioning, including the results of the initial acceptance testing required in Section 1207.2.1.1, shall be provided to the fire code official prior to final inspection and approval and maintained at an approved on-site location. (Material based on NFPA 855 2023 Ed.)

    1207.2.2 Operation and maintenance. An operation and maintenance manual shall be provided to both the ESS owner or their authorized agent and the ESS operator before the ESS is put into operation and shall include the following:

    1. Manufacturer’s operation manuals and maintenance manuals for the entire ESS, or for each component of the system requiring maintenance, that clearly identify the required routine maintenance actions.
    2. Name, address and phone number of a service agency that has been contracted to service the ESS and its associated safety systems.
    3. Maintenance and calibration information, including wiring diagrams, control drawings, schematics, system programming instructions and control sequence descriptions, for all energy storage control systems.
    4. Desired or field-determined control set points that are permanently recorded on control drawings at control devices or, for digital control systems, in system programming instructions.
    5. A schedule for inspecting and recalibrating all ESS controls.
  • CPC § 1603.10 Medium relevance — show source text
    9
    1603.10 A & B
    1603.12
    1603.20
    1604.1 - 1604.3
    1605.3
    1605.3.2
    1605.3.3    		 BSC BSC-
    CG    		 SFM HCD Col6 Col7 DSA Col9 Col10 OSHPD Col12 Col13 Col14 Col15 Col16 Col17 BSCC DPH AGR DWR CEC CA SL SLC
    Adopting Agency
    Adopt Entire Chapter
    Adopt Entire Chapter as
    amended (amended
    sections listed below)
    Adopt only those sections
    that are listed below
    Chapter/Section
    1601.2
    1601.3 & Exceptions 1 & 2
    1601.5
    1601.6
    1601.7
    1602.4_& Exceptions_
    1602.7
    1603.3
    1603.3.1 &Exception
    1603.4
    1603.4.1
    Table 1603.4
    1603.7
    1603.8
    1603.9
    1603.10_A & B_
    1603.12
    1603.20
    1604.1 - 1604.3
    1605.3
    1605.3.2
    1605.3.3    		 BSC BSC-
    CG    		 SFM 1 2 1-AC AC ** SS** SS/CC 1 1R 2 3 4 5 6 6 6 6 6 6 6 6 6
    Adopting Agency
    Adopt Entire Chapter
    Adopt Entire Chapter as
    amended (amended
    sections listed below)
    Adopt only those sections
    that are listed below
    Chapter/Section
    1601.2
    1601.3 & Exceptions 1 & 2
    1601.5
    1601.6
    1601.7
    1602.4_& Exceptions_
    1602.7
    1603.3
    1603.3.1 &Exception
    1603.4
    1603.4.1
    Table 1603.4
    1603.7
    1603.8
    1603.9
    1603.10_A & B_
    1603.12
    1603.20
    1604.1 - 1604.3
    1605.3
    1605.3.2
    1605.3.3
    Adopting Agency
    Adopt Entire Chapter
    Adopt Entire Chapter as
    amended (amended
    sections listed below)
    Adopt only those sections
    that are listed below
    Chapter/Section
    1601.2
    1601.
  • CPC § 302.0 Medium relevance — show source text

    E 302.0 Disposal of Liquid Waste. E 302.1 Disposal. It shall be unlawful for a person to cause, suffer, or permit the disposal of liquid wastes, in a place or manner, except through and by means of an approved drainage system, installed and maintained in accordance with the provisions of the plumbing code. E 302.2 Connections to Plumbing System Required. Equipment and appliances, used to receive or discharge liquid wastes or sewage, shall be connected to the drainage system of the building or premises in accordance with the requirements of the plumbing code and this appendix.

    E 303.0 Abandonment.

    E 303.1 General. An abandoned system or part thereof covered under the scope of this appendix shall be disconnected

    from remaining systems, drained, plugged, and capped in an approved manner.

    E 401.0 Water Conservation and Efficiency. E 401.1 General. The provisions of this section establish the means of conserving potable and nonpotable water used in and around a building.

    E 402.0 Meters.

    E 402.1 Required. A water meter shall be required for buildings connected to a public water system, including municipally supplied reclaimed (recycled) water. In other than single-family houses, multi-family structures not exceeding three stories above grade, and modular houses, a separate meter or submeter shall be installed in the following locations:

    (1) The makeup water supply to cooling towers, evaporative condensers, and fluid coolers. (2) The makeup water supply to one or more boilers collectively exceeding 1 000 000 British thermal units per hour (Btu/h) (293 kW). (3) The water supply to a water-using process where the consumption exceeds 1000 gallons per day (gal/d) (0.0438 L/s), except for manufacturing processes. (4) The makeup water supply to an evaporative cooler having an air flow exceeding 30 000 cubic feet per minute (ft [3] /min) (14.1584 m [3] /s). E 402.2 Consumption Data. A means of communicating water consumption data from submeters to the water consumer shall be provided. E 402.3 Access. Meters and submeters shall be accessible.

    E 403.0 HVAC Water Use.

    E 403.1 Once-Through Cooling. Once-through cooling using potable water is prohibited. E 403.2 Cooling Towers and Evaporative Coolers. Cooling towers and evaporative coolers shall be equipped with makeup water and blow down meters, conductivity controllers, and overflow alarms. Cooling towers shall be equipped with efficiency drift eliminators that achieve drift reduction to 0.002 percent of the circulated water volume for counterflow towers and 0.005 percent for cross-flow towers. E 403.3 Cooling Tower Makeup Water. Not less than 5 cycles of concentration is required for air-conditioning cooling tower makeup water having a total hardness of less than 11 grains per gallon (gr/gal) (188 mg/L) expressed as calcium carbonate. Not less than 3.5 cycles of concentration is required for air-conditioning cooling tower makeup water having a total hardness equal to or exceeding 11 gr/gal (188 mg/L) expressed as calcium carbonate. Exception: Air-conditioning cooling tower makeup water having discharge conductivity range not less than 7 gr/gal (120 mg/L) to 9 gr/gal (154 mg/L) of silica measured as silicon dioxide.

  • CPC § 1506.10.3 Medium relevance — show source text

    1506.10.3 Deactivation and Drainage. The on-site treated nonpotable gray water system and the potable water system within the building shall be provided with the required appurtenances (e.g., valves, air/vacuum relief valves, etc.) to allow for deactivation or drainage as required for a cross-connection test in accordance with Section 1502.3.

    1506.10.4 Near Underground Potable Water Pipe. On-site treated nonpotable gray 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 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 on-site treated nonpotable gray water piping. 1506.10.5 Required Filters. A filter permitting the passage of particulates no larger than 100 microns (100 µm) shall be provided for on-site treated nonpotable gray water supplied to water closets, urinals, trap primers, and drip irrigation system s . 1506.10.6 Disinfection. Where the intended use of onsite treated nonpotable gray water requires disinfec- tion and/or other treatment, on-site treated nonpotable gray water shall be disinfected as needed to ensure the required water quality is obtained at the point of use. Where chlorine is used for disinfection or treatment, water shall be tested for residual chlorine in accordance with ASTM D1253.

    1506.11 Valves. Valves, except fixture supply control valves, shall be equipped with a locking feature. 1506.12 Signs. Signs in buildings using on-site treated nonpotable gray water shall comply with Section s 1501.9, 1501.9.1 and 1501.9.2 and applicable requirements of the Cal- ifornia Building Code . 1506.13 Inspection and Testing. On-site treated nonpotable gray water systems shall be inspected and tested in accordance with Section 1502.1 and/or as required by the Authority Having Jurisdiction .

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    water pressure in the on-site treated non-potable gray water supply system within the building exceeds 80 psi (552 kPa), a pressure reducing valve reducing the pressure to 80 psi (552 kPa) or less to water outlets in the building shall be installed.

    1506.6 Initial Cross-Connection Test. A cross-connection test is required in accordance with Section 1502.3. 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. 1506.7 On-Site Treated Nonpotable Gray Water Sys- tem Materials. On-site treated nonpotable gray water supply, and distribution system materials shall comply with the requirements of this code for potable water supply and distribution systems unless otherwise provided for in this section.

    1506.8 On-Site Treated Nonpotable Gray Water **Devices and Systems.

  • CPC § 1506.0. Medium relevance — show source text

    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

    exclusively for subsurface landscape irrigation.

    drainage systems, including gutters, downspouts, conductors, and leaders shall be in accordance with the 1603.3.2 Prohibited Discharges. Overflows and requirements of this code for storm drainage. bleed-off pipes from roof-mounted equipment and appli ances shall not discharge onto roof surfaces that are

    1602.7.3 Storage Tanks. Rainwater storage tanks shall

    intended to collect rainwater without prior approval from

    comply with Section 1603.5.

    the Authority Having Jurisdiction.

    1602.8 Rainwater Catchment System Color and

    1603.4 Minimum Water Quality. The minimum water

    Marking Information. Rainwater catchment systems shall

    quality for harvested rainwater shall meet the applicable water

    have a colored background in accordance with Section 601.3.

    quality requirements for the intended applications as deter Rainwater catchment systems shall be marked, in lettering in

    mined by the Authority Having Jurisdiction. In the absence of

    accordance with Section 601.3.3, with the words: “CAU water quality requirements determined by the Authority Hav TION: NONPOTABLE RAINWATER, DO NOT DRINK.”

    ing Jurisdiction, the minimum treatment and water quality

    1602.9 Deactivation and Drainage for Cross-Connec- shall be in accordance with Table 1603.4, IAPMO IGC 324 tion Test. The rainwater catchment system and the potable or NSF/ANSI 350. water system within the building shall be provided with the Exception [BSC] : No treatment is required for rainwater required appurtenances (e.g., valves, air or vacuum relief used for subsurface or nonsprinkled surface irrigation where valves, etc.) to allow for deactivation or drainage as required for the maximum storage volume is less than 5000 gallons (18 a cross-connection test in accordance with Section 1605.3. 927 L) where the tank is supported directly upon grade and the

    ratio of height to diameter or width does not exceed 2 to 1 .

    1603.0 Design and Installation. 1603.4.1 Disinfection. Where the initial quality of the

    collected rainwater requires disinfection or other treat-

    1603.1 Rainwater Catchment Systems. The design and

    ment or both, the collected rainwater shall be treated as

    installation of nonpotable rainwater catchment systems shall

    necessary to ensure the required water quality is deliv-

    be in accordance with Section 1603.2 through Section 1603.20.

    ered at the point of use. Where chlorine is used for dis-

    1603.2 Outside Hose Bibbs. Outside hose bibbs shall be infection or treatment, water shall be tested for residual allowed on rainwater piping systems. Hose bibbs supplying chlorine in accordance with ASTM D1253. The levels of rainwater shall be marked with the words: “CAUTION: residual chlorine shall not exceed the levels allowed for NONPOTABLE RAINWATER, DO NOT DRINK” and in the intended use in accordance with the requirements of Figure 1603.2. the local enforcing agency.

  • CPC § 1505.14.2.3 Medium relevance — show source text

    (4) The drain on the recycled water supply system shall be checked for flow during the test and at the end of the test.

    (5) The potable water system shall then be depres- surized and drained.

    (6) The recycled water supply system shall then be activated and pressurized. For the initial cross- connection test, a temporary connection to a potable water supply shall be required to test the recycled water supply system plumbing. At the conclusion of the initial cross-connection test, the temporary connection to the potable water supply shall be disconnected.

    (7) The recycled water supply system shall remain pressurized for a minimum period of time spec- ified by the Authority Having Jurisdiction while the potable water system is empty. The mini- mum period the potable water system is to remain depressurized shall be determined on a case-by-case basis, but in no case shall that period be less than 1 hour.

    (8) All fixtures, potable and reclaimed (recycled) water, shall be tested and inspected for flow. Flow from a potable water system outlet indi- cates a cross-connection. No flow from a recy- cled water supply system outlet will indicate that it is connected to the potable water system.

    (9) The drain on the potable water system shall be checked for flow during the test and at the end of the test.

    (10)Where there is no flow detected in the fixtures that would indicate a cross-connection, the potable water system shall be repressurized.

    Where shutting off the water is not practical for res- idential, institutional, or industrial buildings, the Authority Having Jurisdiction may authorize testing procedures other than those described above. 1505.14.2.3 Discovery of Cross-Connection. In the event that a cross-connection is discovered, the following procedure shall be activated immedi- ately:

    (1) Notify the Authority Having Jurisdiction of the cross-connection.

    (2) The reclaimed (recycled) water piping to the building and its premises shall be shut down at the meter, and the reclaimed (recycled) water riser shall be drained.

    (3) Potable water piping to the building and its premises shall be shut down at the meter.

    (4) The cross-connection shall be uncovered and disconnected.

    2025 CALIFORNIA PLUMBING CODE 321

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS

    (5) The building and its premises shall be retested in accordance with Section 1505.14.2.1 and

    Section 1505.14.2.2.

    (6) The potable water system shall be chlorinated with 50 parts-per-million (ppm) chlorine for 24 hours.

    (7) The potable water system shall be flushed after 24 hours, and a standard bacteriological test shall be performed. Where test results are acceptable, the potable water system shall be permitted to be recharged. 1505.14.2.4 Periodic Inspection. Periodic visual inspections of recycled water supply systems shall be required by the recycled water supplier or designee following the procedures in Section _1505.14.2.1.

  • CPC § 11.0 Medium relevance — show source text

    11.0 - 1.11.11_|||X|||||||||||||||||||||| |1.13.0||||||||||||||||||||X||||| |Division II - Scope and
    Administration||||||||||||||||||||||||| |101.0||||||||||X|X|X||X|X|||||||||| |102.0||||||||||X|X|X||X|X|||||||||| |103.0||||||||||X|X|X||X|X|||||||||| |104.2 Items 1 & 2||||X|X|||||||||||||||||||| |104.3.1||||||||||X|X|X||X|X|||||||||| |104.4.3.1|X|||||||||||||||||||||||| |105.0||||||||||X|X|X||X|X||||||||||

    This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

    2 2025 CALIFORNIA PLUMBING CODE

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    CHAPTER 1

    ADMINISTRATION

    DIVISION I

    CALIFORNIA ADMINISTRATION

    1.1.0 General.

    1.1.1 Title. These regulations shall be known as the Califor- nia Plumbing Code, may be cited as such and will be referred to herein as “this code.” The California Plumbing Code is Part 5 of thirteen parts of the official compilation and publi- cation of the adoption, amendment, and repeal of plumbing regulations to the California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This part incorporates by adoption the 2024 Uniform Plumb- ing Code of the International Association of Plumbing and Mechanical Officials with necessary California amendments.

    1.1.2 Purpose. The purpose of this code is to establish the minimum requirements to safeguard the public health, safety and general welfare through structural strength, means of egress facilities, stability, access to persons with disabilities, sanitation, adequate lighting and ventilation, and energy con- servation; safety to life and property from fire and other haz- ards attributed to the built environment; and to provide safety to fire fighters and emergency responders during emergency operations.

    1.1.3 Scope. The provisions of this code shall apply to the construction, alteration, movement, enlargement, replace- ment, repair, equipment, use and occupancy, location, main- tenance, removal, and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures throughout the State of California.

  • CPC § 1502.3.2. Medium relevance — show source text

    (2) A potable water supply may be connected temporarily for the initial cross-connection test of the on-site treated non- potable gray water system as provided in Section 1502.3.2. 1506.5 Water Pressure. On-site treated non-potable gray water systems supplying water to water closets, urinals, and trap primers shall be capable of delivering not less than 15 pounds-force per square inch (psi) (103 kPa) residual pressure at the highest and most remote outlet served. Where the

    TABLE 1505.16 MINIMUM RECLAIMED (RECYCLED) WATER SOURCE TESTING, INSPECTION, AND MAINTENANCE FREQUENCY

    DESCRIPTION MINIMUM FREQUENCY*

    Inspect and clean filters and screens, and replace (where necessary). [Every 3 months.]

    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 from 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.

    * Note: Frequency is as described in this table, or more frequently as required by manufacturer’s instructions and/or the Authority Having Jurisdiction.

    322 2025 CALIFORNIA PLUMBING CODE

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS

    1506.10.3 Deactivation and Drainage. The on-site treated nonpotable gray water system and the potable water system within the building shall be provided with the required appurtenances (e.g., valves, air/vacuum relief valves, etc.) to allow for deactivation or drainage as required for a cross-connection test in accordance with Section 1502.3.

    1506.10.4 Near Underground Potable Water Pipe. On-site treated nonpotable gray 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 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 on-site treated nonpotable gray water piping. 1506.10.5 Required Filters. A filter permitting the passage of particulates no larger than 100 microns (100 µm) shall be provided for on-site treated nonpotable gray water supplied to water closets, urinals, trap primers, and drip irrigation system s . 1506.10.6 Disinfection. Where the intended use of onsite treated nonpotable gray water requires disinfec- tion and/or other treatment, on-site treated nonpotable gray water shall be disinfected as needed to ensure the required water quality is obtained at the point of use. Where chlorine is used for disinfection or treatment, water shall be tested for residual chlorine in accordance with ASTM D1253.

  • CPC § 1605.3.3 Medium relevance — show source text

    NONPOTABLE RAINWATER CATCHMENT SYSTEMS

    (3) Fixtures, potable, and rainwater shall be tested and inspected for flow. Flow from a rainwater catchment water system outlet shall indicate a cross-connection. No flow from a potable water outlet shall indicate that it is connected to the rainwater system.

    (4) The drain on the rainwater catchment water system shall be checked for flow during the test and at the end of the period.

    (5) The potable water system shall then be completely drained.

    (6) The rainwater catchment water system shall then be activated and pressurized. When rainwater is not available for the initial cross-connection test, a tem- porary connection to a potable water supply shall be required. At the conclusion of the initial cross- connection test, the temporary connection to the potable water supply shall be disconnected.

    (7) The rainwater catchment water system shall remain pressurized for a minimum period of time specified by the Authority Having Jurisdiction while the potable water system is empty. The minimum period the potable water system is to remain depressurized shall be determined on a case-by-case basis, but in no case shall that period be less than 1 hour.

    (8) Fixtures, potable and rainwater catchment, shall be tested and inspected for flow. Flow from a potable water system outlet shall indicate a cross-connection. No flow from a rainwater catchment water outlet shall indicate that it is connected to the potable water system.

    (9) The drain on the potable water system shall be checked for flow during the test and at the end of the period.

    (10)Where there is no flow detected in the fixtures which would indicate a cross-connection, the potable water system shall be repressurized. 1605.3.3 Discovery of Cross-Connection. In the event that a cross-connection is discovered, the following procedure, in the presence of the Authority Having Jurisdiction, shall be activated immediately:

    (1) Rainwater catchment piping to the building shall be shutdown at the supply source(s), and the rainwater riser shall be drained.

    (2) Potable water piping to the building shall be shutdown at the meter.

    (3) The cross-connection shall be uncovered and disconnected.

    (4) The building shall be retested following procedures listed in Section 1605.3.1 and Section 1605.3.2.

    (5) The potable water system shall be chlorinated with 50 ppm chlorine for 24 hours.

    (6) The potable water system shall be flushed after 24 hours, and a standard bacteriological test shall be performed. Where test results are acceptable, the potable water system shall be permitted to be recharged.

    332 2025 CALIFORNIA PLUMBING CODE

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    CALIFORNIA PLUMBING CODE – MATRIX ADOPTION TABLE

    CHAPTER 17 - REFERENCED STANDARDS

    (Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

  • CPC § 101.2.2 Medium relevance — show source text

    CFC—25: California Fire Code

    101.2.2, 101.4.2, 301.3.1, 302.2, 307.1, 308.1, 802.2.1, 802.2.3, 803.2.3, 803.4.1.1, 803.4.1.2, 803.4.1.3, 803.4.1.4, 803.4.1.5, 803.4.1.6, Table 804.5.1.1(1), 904.1.5, 1011.6.1.1, 1303.1.2, 1305.2.8.1, 1305.2.14, 1305.2.14.1, 1401.2, 1501.1, 1501.5, 1502.1, 1502.1.1, 1502.2, 1502.3, 1504.1, 1507.1, 1507.2

    CMC—25: California Mechanical Code

    302.2, 702.7, 807.1, 902.1.1, 1008.1, 1305.2.7.1, 1305.2.8, 1305.2.8.1

    CPC—25: California Plumbing Code

    302.2, 408.1, 702.7, 1009.1, 1009.2, 1009.3, 1009.5, 1302.1.6, 1503.1

    16-4 2025 CALIFORNIA EXISTING BUILDING CODE

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

    REFERENCED STANDARDS

    CRC—25: California Residential Code

    101.2, 101.4.1, 104.3.1, 109.3.3, 109.3.10, 302.2, 307.1, 308.1, 401.3, 402.1, 405.2.6, 502.2, 502.3, 502.4, 503.2, 503.3, 503.11, 505.2, 505.3, 507.3, 701.3, 702.4, 702.5, 706.2, 708.1, 805.2, 806.4, 809.1, 906.2, 907.1, 1011.2.1, 1103.1, 1103.2, 1103.3, 1104.1, 1201.4, 1302.1.2, 1302.1.3, 1302.1.3, 1303.1.3, 1401.2, 1402.1, 1402.2, 1402.2.1, 1402.3, 1402.4, 1402.5, 1402.6

    ICC 300—2023: ICC Standard on Bleachers, Folding and Telescopic Seating and Grandstands

    301.1.1, 401.1.1, 1401.1.1

    ICC A117.1—2017: Accessible and Usable Buildings and Facilities

  • CPC § 705.10 Medium relevance — show source text

    Waste,
    and Vent (DWV), Sewer, Sanitary, and Storm Plumbing Sys-
    tems for Above and Below Ground Use|Joints|705.10|

    340 2025 CALIFORNIA PLUMBING CODE

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    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
    701.2
    ASTM D2235-2021 Standard Specification for Solvent Cement for Acrylonitrile-
    Butadiene-Styrene (ABS) Plastic Pipe and Fittings    		 Joints 705.1.2
    ASTM D2239-2021 Standard Specification for Polyethylene (PE) Plastic Pipe
    (SIDR-PR) Based on Controlled Inside Diameter    		 Piping Table 604.1
    ASTM D2241-2020 Standard Specification for Poly (Vinyl Chloride) (PVC) Pressure-
    Rated Pipe (SDR Series)    		 Piping Table 604.1
    ASTM D2464-2015 Standard Specification for Threaded Poly (Vinyl Chloride)
    (PVC) Plastic Pipe Fittings, Schedule 80    		 Fittings Table 604.1
    ASTM D2466-2021 Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic
    Pipe Fittings, Schedule 40    		 Fittings Table 604.1
    ASTM D2467-2020 Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic
    Pipe Fittings, Schedule 80    		 Fittings Table 604.1
    ASTM D2513-2020 Standard Specification for Polyethylene (PE) Gas Pressure
    Pipe, Tubing, and Fittings    		 Piping 1208.5.4, 1208.5.6.2,
    1208.5.10.2,
    1210.1.7.1(1)
    ASTM D2564-2020 Standard Specification for Solvent Cements for Poly (Vinyl
    Chloride) (PVC) Plastic Piping Systems    		 Joints 605.12.2, 705.6.
  • CPC § 1603.13 Medium relevance — show source text

    1603.13 Pumps. Pumps serving rainwater catchment systems shall be listed. Pumps supplying water to water closets, urinals, and trap primers shall be capable of delivering not

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    330 2025 CALIFORNIA PLUMBING CODE

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    NONPOTABLE RAINWATER CATCHMENT SYSTEMS

    CAUTION NONPOTABLE RAINWATER, DO NOT DRINK. DO NOT CONNECT TO DRINKING WATER

    SYSTEM. NOTICE: CONTACT BUILDING MANAGE MENT BEFORE PERFORMING ANY WORK ON THIS

    WATER SYSTEM.

    This sign shall be posted in a location that is visible to anyone working on or near rainwater equipment.

    1605.0 Inspection and Testing. 1605.1 General. Rainwater catchment systems shall be inspected and tested in accordance with Section 1605.2 and Section 1605.3.

    1605.2 Supply System Inspection and Test. Rainwater catchment systems shall be inspected and tested in accordance with the applicable provisions of this code for testing of potable water and storm drainage systems. Storage tanks shall be filled with water to the overflow opening for a period of 24 hours, and during the inspection, or by other means as approved by the Authority Having Jurisdiction. Seams and joints shall be exposed during the inspection and checked for watertightness. 1605.3 Cross-Connection Inspection and Testing. An initial visual inspection and an initial cross-connection test shall be performed on both the potable and rainwater catchment water systems before the initial operation of the rain- water catchment system. During an initial or subsequent cross-connection test, the potable and rainwater catchment water systems shall be isolated from each other and independently inspected and tested to ensure there is no crossconnection in accordance with Section 1602.5. Initial or subsequent inspections or tests shall be performed in accordance with Section 1605.3.1 through Section 1605.3.3 . 1605.3.1 Visual System Inspection. Prior to commencing the cross-connection testing, a dual system inspection shall be conducted by the Authority Having Jurisdiction and other authorities having jurisdiction as follows:

    (1) Pumps, equipment, equipment room signs, and exposed piping in an equipment room shall be checked.

    1605.3.2 Cross-Connection Test. A cross-connec- tion test shall be performed in the presence of the Authority Having Jurisdiction or other authorities having jurisdiction to determine whether a cross-connection has occurred as follows:

    (1) The potable water system shall be activated and pressurized. The rainwater catchment water system shall be shut down and completely drained.

    (2) The potable water system shall remain pressurized for a minimum period of time specified by the Authority Having Jurisdiction while the rainwater catchment water system is empty. The minimum period the rainwater catchment water system is to remain depressurized shall be determined on a caseby-case basis, taking into account the size and complexity of the potable and rainwater catchment water distribution systems, but in no case shall that period be less than 1 hour.

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Frequently asked questions

Who decides whether a tank removal/fill method is acceptable?

The Authority Having Jurisdiction (AHJ) — the code requires tank removal or filling to be done “in a manner satisfactory to the Authority Having Jurisdiction” under § 1601.11.2.

Can I just leave an abandoned rainwater piping loop buried and capped?

No — an abandoned system must be disconnected, drained, plugged, and capped in an approved manner per § 1601.11.1; leaving piping in service or merely isolated is not compliant.

Does the 5000‑gallon exception in § 1602.9 eliminate abandonment duties?

No. The 5000‑gallon exception in § 1602.9 concerns treatment requirements for use cases (subsurface irrigation); it does not remove the abandonment/fill/remove requirements of § 1601.11.2 for an underground tank.

What appurtenances are required to allow deactivation for cross‑connection tests?

The code cites typical appurtenances such as valves, air or vacuum relief valves, and similar devices so the system can be deactivated/drained for testing as required under § 1602.9.

Is there any minimum time the potable or nonpotable system must remain depressurized during a cross‑connection test?

The cross‑connection testing sequence referenced by § 1602.9 points to the testing rules in § 1605.3, which specify that the system being held empty/pressurized must remain so for a minimum period (case‑by‑case) and in no case less than 1 hour for initial tests.

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