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Earlier editions: 20222019

Chapter 6 — WATER SUPPLY AND DISTRIBUTION

601.3 Identification of a Potable and Nonpotable

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.

Water System. In buildings where potable water and nonpotable water systems are installed, each system shall be clearly identified in accordance with Section 601.3.1 through Section 601.3.5.

601.3.1 Potable Water. Green background with white lettering.

601.3.2 Color and Information. Each system shall be identified with a colored pipe or band and coded with paints, wraps, and materials compatible with the piping.

Except as required by Section 601.3.3, nonpotable water systems shall have a yellow background with black uppercase lettering, with the words “CAUTION: NONPOTABLE WATER, DO NOT DRINK.” Each nonpotable system shall be identified to designate the liquid being conveyed, and the direction of normal flow shall be clearly shown. The minimum size of the letters and length of the color field shall comply with Table 601.3.2.

[HCD 1 & HCD 2] An international symbol of a glass in a circle with a slash through it shall be provided sim- ilar to that shown in Figure 601 for all nonpotable water

systems.

WATER SUPPLY AND DISTRIBUTION

FIGURE 601

INTERNATIONAL SYMBOL

The background color and required information shall be indicated every 20 feet (6096 mm) but not less than once per room, and shall be visible from the floor level.

601.3.3 Alternate Water Sources. Alternate water source systems shall have a purple (Pantone color No. 512, 522C, or equivalent) background with uppercase lettering and shall be field or factory marked as follows:

(1) Gray water systems shall be marked in accordance with this section with the words “CAUTION: NONPOTABLE GRAY WATER, DO NOT DRINK” in black letters.

(2) Reclaimed (recycled) water systems for outdoor applications shall be marked in accordance with this section with the words: “CAUTION: NONPOTABLE RECLAIMED (RECYCLED) WATER, DO NOT DRINK” in black letters.

(3) On-site treated water systems shall be marked in accordance with this section with the words: “CAU TION: ON-SITE TREATED NONPOTABLE WATER, DO NOT DRINK” in black letters.

(4) Rainwater catchment systems shall be marked in accordance with this section with the words: “CAU TION: NONPOTABLE RAINWATER, DO NOT DRINK” in black letters.

Exception: [DWR] For recycled water supply systems that are within or a part of a building, the provisions of Section 1505.7 shall apply.

TABLE 601.3.2

MINIMUM LENGTH OF COLOR FIELD AND SIZE OF LETTERS

OUTSIDE DIAMETER
OF PIPE OR
COVERING
(inches)		 MINIMUM LENGTH OF
COLOR FIELD
(inches)		 MINIMUM SIZE OF
LETTERS
(inches)


1⁄2 to 11⁄4		 8 1⁄2


11⁄2 to 2		 8 3⁄4


21⁄2 to 6		 12 11⁄4


8 to 10		 24 21⁄2

Over 10
 32
 31⁄2

For SI units: 1 inch = 25.4 mm

601.3.4 Fixtures. Where vacuum breakers or backflow preventers are installed with fixtures listed in Chapter 17, identification of the discharge side shall be permitted to be omitted.

601.3.5 Outlets. Each outlet on the nonpotable water line that is used for special purposes shall be posted with black uppercase lettering as follows: “CAUTION: NONPOTABLE WATER, DO NOT DRINK.”

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▸Contents — California Plumbing Code (Title 24, Part 5)
California Plumbing Code (Title 24, Part 5)
  1. Chapter 1 — GENERAL CODE PROVISIONS
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — GENERAL REGULATIONS
  4. Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
  5. Chapter 5 — WATER HEATERS
  6. ▸Chapter 6 — WATER SUPPLY AND DISTRIBUTION
    Overview
    1. 601.1 Applicability. This chapter shall govern the materials,
    2. 601.2 Water Supply and Flushing. Each plumbing fixture shall b…
    3. 601.3 Identification of a Potable and Nonpotable
    4. 601.4 Schools of Cosmetology and Cosmetological
    5. 601.5 Meat and Poultry Processing Plants. [AGR]
    6. 601.6 Collection Centers and Facilities. [AGR]
    7. 601.7 Renderers. [AGR] This area shall be provided with
    8. 601.8 Horse Meat and Pet Food Establishments. [AGR]
    9. 602.1 Prohibited Installation. No installation of potable
    10. 602.2 Cross-Contamination. No person shall make a connection o…
    11. 602.3 Backflow Prevention. No plumbing fixture, device,
    12. 602.4 Approval by Authority. No water piping supplied
    13. 603.1 General. Cross-connection control shall be provided
    14. 603.2 Approval of Devices or Assemblies. Before a
    15. 603.3 Backflow Prevention Devices, Assemblies, and
    16. 603.4 General Requirements. Assemblies shall comply
    17. 603.5 Specific Requirements. Specific requirements for
    18. 604.1 Pipe, Tube, and Fittings. Pipe, tube, fittings, solvent …
    19. 604.2 Lead Content. The maximum allowable lead content
    20. 604.3 Copper or Copper Alloy Tube. Copper or copper
    21. 604.4 Hard-Drawn Copper or Copper Alloy Tubing.
    22. 604.5 Flexible Connectors. Flexible water connectors
    23. 604.6 Cast-Iron Fittings. Cast-iron fittings up to and
    24. 604.7 Malleable Iron Fittings. Malleable iron water fittings s…
    25. 604.8 Previously Used Piping and Tubing. Piping and
    26. 604.9 Epoxy Coating. The epoxy coating used on existing, under…
    27. 604.10 Plastic Materials. Approved plastic materials shall
    28. 604.11 Solder. Solder shall comply with the requirements of
    29. 604.12 Flexible Corrugated Connectors. Flexible corrugated con…
    30. 604.13 Water Heater Connectors. Flexible metallic (copper and …
    31. 605.1 Copper or Copper Alloy Pipe, Tubing, and
    32. 605.2 CPVC Plastic Pipe and Joints. CPVC plastic pipe
    33. 605.3 CPVC/AL/CPVC Plastic Pipe and Joints. Chlorinated polyvi…
    34. 605.4 Ductile Iron Pipe and Joints. Ductile iron pipe
    35. 605.5 Galvanized Steel Pipe and Joints. Galvanized
    36. 605.6 PE Plastic Pipe/Tubing and Joints. PE plastic
    37. 605.7 PE-AL-PE Plastic Pipe/Tubing and Joints. PEAL-PE plastic…
    38. 605.8 PE-RT. Polyethylene of raised temperature (PE-RT)
    39. 605.9 PEX Plastic Tubing and Joints. PEX plastic tubing and fi…
    40. 605.10 PEX-AL-PEX Plastic Tubing and Joints. PEXAL-PEX plastic…
    41. 605.11 Polypropylene (PP) Piping and Joints. PP pipe
    42. 605.12 PVC Plastic Pipe and Joints. PVC plastic pipe
    43. 605.13 Stainless Steel Pipe and Joints. Joining methods for st…
    44. 605.14 Slip Joints. In water piping, slip joints shall be perm…
    45. 605.15 Dielectric Unions. Dielectric unions where installed
    46. 605.16 Joints Between Various Materials. Joints
    47. 606.1 General. Valves up to and including 2 inches (50
    48. 606.2 Fullway Valve. A fullway valve controlling outlets
    49. 606.3 Multidwelling Units. In multidwelling units, one or
    50. 606.4 Multiple Openings. Valves used to control two or
    51. 606.5 Control Valve. A control valve shall be installed
    52. 606.6 Accessible. Required shutoff or control valves shall
    53. 606.7 Multiple Fixtures. A single control valve shall be
    54. 606.8 [OSHPD 1, 1R, 2, 3, 4 & 5] Each riser or branch
    55. 606.9 Check Valve Required. All systems that circulate
    56. 606.10 Leak Detection Devices. Where leak detection
    57. 607.1 General. Potable water supply tanks shall be installed in
    58. 607.2 Private Well Water Tanks. Pressurized potable water
    59. 607.3 Potable Water Tanks. Potable water supply tanks,
    60. 607.4 Venting. Tanks used for potable water shall be tightly
    61. 607.5 Overflow. Tanks shall have not less than a 16 square
    62. 607.6 Valves. Pressurized tanks shall be provided with a listed
    63. 608.1 Inadequate Water Pressure. Where the water pressure in t…
    64. 608.2 Excessive Water Pressure. Where static water
    65. 608.3 Expansion Tanks, and Combination Tempera-
    66. 608.4 Pressure Relief Valves. Each pressure relief valve
    67. 608.5 Discharge Piping. The discharge piping serving a
    68. 608.6 Water-Heating Devices. A water-heating device
    69. 608.7 Vacuum Relief Valves. Where a hot-water storage
    70. 609.1 Installation. Water piping shall be adequately supported…
    71. 609.2 Trenches. Water pipes shall not be run or laid in the
    72. 609.3 Under Concrete Slab. Water piping installed within
    73. 609.4 Testing. Upon completion of a section or of the entire
    74. 609.5 Unions. Unions shall be installed in the water supply
    75. 609.6 Location. Except as provided in Section 609.7, no
    76. 609.7 Abutting Lot. Nothing contained in this code shall
    77. 609.8 Pumps. Pumps shall be installed in accordance with
    78. 609.9 Low-Pressure Cutoff Required on Booster
    79. 609.10 Disinfection of Potable Water System. New or
    80. 609.11 Water Hammer. [Not adopted by HCD] Building
    81. 609.12 Pipe Insulation. Insulation of domestic hot water
    82. 610.1 Size. The size of each water meter and each potable
    83. 610.2 Pressure Loss. Where a water filter, water softener,
    84. 610.3 Quantity of Water. The quantity of water required to be
    85. 610.4 Sizing Water Supply and Distribution Systems.
    86. 610.5 Sizing per Appendices A, C, and M . Except as
    87. 610.6 Friction and Pressure Loss. Except where the type
    88. 610.7 Conditions for Using Table 610.4. On a proposed
    89. 610.8 Size of Meter and Building Supply Pipe Using
    90. 610.9 Size of Branches. Where Table 610.4 is used, the minimum…
    91. 610.10 Sizing for Flushometer Valves. Where using
    92. 610.11 Sizing Systems for Flushometer Tanks. The size
    93. 610.12 Sizing for Velocity. Water piping systems shall not
    94. 610.13 Exceptions. The provisions of this section relative
    95. 611.1 Application. Drinking water treatment units shall
    96. 611.2 Air Gap Discharge. Discharge from drinking water
    97. 611.3 Connection Tubing. The tubing to and from drinking water…
    98. 611.4 Sizing of Residential Softeners. Residential-use
    99. 612.1 Installation. Residential Sprinkler Systems shall be
    100. 613.1 The domestic water-heating equipment and distribu-
    101. 613.2 At least two pieces of hot-water-heating equipment shall
    102. 613.3 Instantaneous heaters are permitted for supplying hot
    103. 613.4 Water storage tanks shall be fabricated of corrosion-
    104. 613.5 Temperature control valves shall be provided to auto-
    105. 613.6 Hot-water distribution system serving patient care areas
    106. 613.7 At fixtures where water exceeding 125°F (52°C) is acces-
    107. 613.8 Sectionalizing valves shall be provided as required by
    108. 613.9 Hot water distribution shall include test ports and valved
    109. 614.1 Dialysis water feedlines shall be CPVC (chlorinated
    110. 614.2 All piping for multistation or central dialysis units sh…
    111. 614.3 All valves shall be located in accessible locations.
    112. 614.4 Piping and valves shall be identified according to their
    113. 614.5 A means of preventing backwashing or flushing of the
    114. 614.6 A continuous audible alarm shall sound at the nurses’
    115. 614.7 Water treatment equipment and water used for dialysis
    116. 614.8 A diagram of all piping as installed shall be posted at …
    117. 615.1 Uses Not Permitted.
    118. 615.2 [OSHPD 1, 1R, 2, 3, 4 & 5] Non-potable water sys-
    119. 615.3 [OSHPD 1, 1R, 2, 3, 4 & 5] Outlets for non-potable
    120. 616.1 For new acute care hospital buildings submitted after
    121. 616.2 The emergency supply of water shall be provided at ade-
    122. 616.3 Storage tank connections and circulation shall be
  7. Chapter 7 — SANITARY DRAINAGE
  8. Chapter 8 — INDIRECT WASTES
  9. Chapter 9 — VENTS
  10. Chapter 10 — TRAPS AND INTERCEPTORS
  11. Chapter 11 — STORM DRAINAGE
  12. Chapter 12 — FUEL GAS PIPING
  13. Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
  14. Chapter 14 — FIRESTOP PROTECTION
  15. Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
  16. Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
  17. Chapter 17 — REFERENCED STANDARDS
  18. Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
  19. Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
  20. Appendix C — ALTERNATE PLUMBING SYSTEMS
  21. Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
  22. Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
  23. Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
  24. Appendix G — SIZING OF VENTING SYSTEMS
  25. Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
  26. Appendix I — INSTALLATION STANDARDS
  27. Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
  28. Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
  29. Appendix L — SUSTAINABLE PRACTICES
  30. Appendix M — PEAK WATER DEMAND CALCULATOR
  31. Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
  32. Appendix O — NON-SEWERED SANITATION SYSTEMS
  33. Appendix P — PROFESSIONAL QUALIFICATIONS
  34. Appendix Q — INDOOR HORTICULTURAL FACILITIES
  35. Appendix R — TINY HOUSES
  36. Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS

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