Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
1505.12 Pipe Separation in Trenches .
California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-09-10 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
Reclaimed (recycled) water pipes shall be permitted to be run or laid in the same trench as potable water pipes with 12 inches (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 horizontal separation shall be increased to 48 inches ( 1220 mm). The potable water piping shall be installed at an elevation above the reclaimed (recycled) water piping. Reclaimed (recycled) water pipes laid in the same trench or crossing building sewer or drainage piping shall be installed in accordance with Section 609.0 and Section 720.0 of this code for water pipes .
320 2025 CALIFORNIA PLUMBING CODE
ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
dance with Section 1505.14.2.1 through Section 1505.14.2.4. The inspection and testing shall be per- formed by a cross-connection control specialist who has valid certification from a certifying organization recog- nized by the State Water Resources Control Board pur- suant to its Cross-Connection Control Policy Handbook. (1) Written reports of cross-connection inspections and testing shall be performed as provided in California Code of Regulations, Title 22, Section 60316.
(2) A cross-connection test pursuant to Section 1505.14.2.2 shall be performed on the premises of a recycled water supply system when there is material reason to believe that the potable water system or recycled water supply system separation from another water supply has been compromised. A material reason to believe that the system has been compromised may be based on, but is not limited to, evidence gathered (a) during a visual inspection performed pursuant to Section 1505.14.2.1, (b) as a result of an inspection performed following com- plaints of water quality or flow conditions consis- tent with a compromised system, or (c) during a visual inspection that indicates that the recycled water supply system has been modified. 1505.14.2.1 Visual System Inspection. A visual dual system inspection shall be conducted by the Authority Having Jurisdiction and other authorities having jurisdiction to verify that no modifications were made, and that no cross-connections are visi- ble as follows:
(1) Meter locations of the reclaimed (recycled) water source and potable water lines shall be checked.
(2) All pumps and equipment, equipment room signs, and exposed piping in equipment room shall be checked.
(3) All valves shall be checked to ensure that the valve lock seals are still in place and intact. Valve control door signs shall be checked to verify that no signs have been removed.
1505.14.2.2 Cross-Connection Test. A cross- connection test shall be performed pursuant to Sec- tion 1505.14.2. The test shall be conducted 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 recycled water supply system shall be shut down, depressurized, and drained.
(2) The potable water system shall remain pressur- ized for a minimum period of time specified by the Authority Having Jurisdiction while the recycled water supply system is empty. The min- imum period the recycled water supply system is to remain depressurized shall be determined on a case-by-case basis, taking into account the size and complexity of the potable and the recy- cled water supply systems, but in no case shall that period be less than 1 hour.
(3) All fixtures, potable and reclaimed (recycled) water source, shall be tested and inspected for flow. Flow from a recycled water supply system outlet indicates a cross-connection. No flow from a potable water outlet shall indicate that it is connected to the recycled water supply system.
(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.
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. Pursuant to California Code of Regu- lations, Title 22, Section 60316, annual visual inspections shall be required for recycled water sup- ply systems that are within or a part of a building.
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Ask AI about this code▸Contents — California Plumbing Code (Title 24, Part 5)
- Chapter 1 — GENERAL CODE PROVISIONS
- Chapter 2 — DEFINITIONS
- Chapter 3 — GENERAL REGULATIONS
- Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
- Chapter 5 — WATER HEATERS
- Chapter 6 — WATER SUPPLY AND DISTRIBUTION
- Chapter 7 — SANITARY DRAINAGE
- Chapter 8 — INDIRECT WASTES
- Chapter 9 — VENTS
- Chapter 10 — TRAPS AND INTERCEPTORS
- Chapter 11 — STORM DRAINAGE
- Chapter 12 — FUEL GAS PIPING
- Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
- Chapter 14 — FIRESTOP PROTECTION
▸Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
Overview- 1501.1 Applicability. [BSC-CG, DWR & HCD 1] The provisions of …
- 1501.2 System Design. [BSC-CG, HCD 1 & DWR]
- 1501.3 Permit. [BSC-CG, HCD 1 & DWR] It shall be
- 1501.4 Component Identification. System components
- 1501.5 Maintenance and Inspection. [BSC-CG, HCD
- 1505.16 .
- 1501.6 Operation and Maintenance Manual. [BSC-
- 1501.7 Minimum Water Quality Requirements. [BSC-
- 1501.8 Material Compatibility. Alternate water source systems …
- 1501.9 Signage. [BSC-CG, HCD 1, HCD 2 & HCD 1-
- 1501.10 System Controls. Controls for pumps, valves, and
- 1502.1 General. Alternate water source systems shall be
- 1502.2 Supply System Inspection and Test. Alternate
- 1502.3 Cross-Connection Inspection and Testing. An
- 1502.4 Separation Requirements. Underground alternate
- 1502.5 Abandonment. Alternate water source systems that
- 1502.6 Sizing. Unless otherwise provided for in this chapter, …
- 1503.1 General. The provisions of this section shall apply to
- 1503.2 System Requirements. Gray water shall be permitted to b…
- 1503.3 Connections to Potable and Reclaimed (Recy-
- 1503.4 Location. No gray water system or part thereof shall
- 1503.5 Plot Plan Submission. No permit for a gray water
- 1503.6 Prohibited Location. Where there is insufficient
- 1503.7 Drawings and Specifications. The Authority Having Juris…
- 1503.8 Procedure for Estimating Gray Water Dis-
- 1503.9 Gray Water System Components. Gray water
- 1504.1 General. Irrigation or disposal fields shall be permitt…
- 1504.2 Required Area of Subsurface Irrigation
- 1504.3 Determination of Maximum Absorption
- 1504.4 Groundwater Level. No excavation for an irrigation fiel…
- 1504.5 Irrigation, Disposal Field and Mulch Basin
- 1504.6 Reserved.
- 1504.7 Reserved .
- 1504.8 Gray Water System Color and Marking Infor-
- 1504.9 Other Collection and Distribution Systems.
- 1504.10 Testing. Building drains and vents for gray water
- 1504.11 Maintenance. Gray water systems and components shall b…
- 1505.1 General. The provisions of Section 1505.0 through
- 1505.2 Permit. It shall be unlawful for a person to construct,
- 1505.3 System Changes. No changes or connections shall
- 1505.4 Connections to Potable or Recycled Water
- 1505.5 Water Pressure. Reclaimed (recycled) water systems supp…
- 1505.6 Initial Cross-Connection Test. A cross-connection
- 1505.7 Recycled Water Supply System Materials.
- 1505.8 Recycled Water Supply System Color and
- 1505.9 Valves. Valves, except fixture supply control valves,
- 1505.13 Signage . Signs in rooms and water closet tanks in
- 1505.14 Inspection and Testing. Recycled water supply
- 1505.10 Hose Bibbs. Hose bibbs shall not be allowed on
- 1505.11 Required Appurtenances. The recycled water
- 1505.12 Pipe Separation in Trenches . Reclaimed (recycled) wat…
- 1505.15 Minimum Water Quality Requirements for
- 1505.16 Maintenance and Inspection. Recycled water
- 1506.1 General. The provisions of this section shall apply
- 1506.2 Plumbing Plan Submission. No permit for an
- 1506.3 System Changes. No changes or connections shall
- 1506.4 Connections to Potable or Recycled Water
- 1506.5 Water Pressure. On-site treated non-potable gray
- 1506.11 Valves. Valves, except fixture supply control
- 1506.12 Signs. Signs in buildings using on-site treated nonpot…
- 1506.13 Inspection and Testing. On-site treated nonpotable gra…
- 1506.6 Initial Cross-Connection Test. A cross-connection test …
- 1506.7 On-Site Treated Nonpotable Gray Water Sys-
- 1506.8 On-Site Treated Nonpotable Gray Water
- 1506.9 On-Site Treated Nonpotable Gray Water Sys-
- 1506.10 Design and Installation. The design and installation o…
- Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
- Chapter 17 — REFERENCED STANDARDS
- Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
- Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
- Appendix C — ALTERNATE PLUMBING SYSTEMS
- Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
- Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
- Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
- Appendix G — SIZING OF VENTING SYSTEMS
- Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
- Appendix I — INSTALLATION STANDARDS
- Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
- Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
- Appendix L — SUSTAINABLE PRACTICES
- Appendix M — PEAK WATER DEMAND CALCULATOR
- Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
- Appendix O — NON-SEWERED SANITATION SYSTEMS
- Appendix P — PROFESSIONAL QUALIFICATIONS
- Appendix Q — INDOOR HORTICULTURAL FACILITIES
- Appendix R — TINY HOUSES
- Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS