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California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-10-23 · California
CBSC: official editions, supplements and errata
Italicized text is a California amendment to the model code, as printed in the official publication.
Cite as: 2025 California Plumbing Code (Title 24, Part 5) · Effective January 1, 2026 · Official source: Building Standards Commission
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OBSTRUCTIONS
OF FLOW . . . . . . . . . . . . . . . . . . . . . . . . . . . .310.5, 315.2
OCCUPANT LOAD FACTOR (BSC, DSA) . . . . . . . .Table 4-1
OFFSETS
Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217.0
Drainage . . . . . . . . . . . . . .706.4, C 304.3.1, C 304.3.2, C 304.4, C 401.4, C 601.7
Medical gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1320.2
Prohibited use . . . . . . . . . . . . . . . . . . . . . . . . . . .402.6.3
Venting (fuel gas) . . . . . . . . . . . . . . .509.6.2.2, 510.1.2,
510.2.4, 510.2.16 Venting (plumbing) . . . . . . . . . . . . . . . . . . . . . . . .910.5
OIL AND FLAMMABLE INTERCEPTORS . . . . . . . . .1017.0
ONE- AND TWO-FAMILY DWELLINGS . . . . . . . . . . . . .301.7
ON-SITE TREATED NONPOTABLE
WATER SYSTEMS
Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217.0
Minimum water quality requirements . . . . . . . . . .1501.7 Operation and maintenance manual . . . . . . . . . .1501.6 Signage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .601.3.3
ON-SITE TREATED NONPOTABLE
GRAY WATER SYSTEMS . . . . . . . . . . . . . . . . . . . . . .1506.0
Color and marking information . . . . . . . . . . . . . .1506.8 Connections to other systems . . . . . . . . . . . . . . .1503.3 Devices and systems . . . . . . . . . . . . . . . . . . . . . .1506.7
Disinfection . . . . . . . . . . . . . . . . . . . . . . . . . . .1506.10.6
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1506.6
Minimum water quality requirements . . . . . . . . . .1501.7 Operation and maintenance manual . . . . . . . . . .1501.6 Signage . . . . . . . . . . . . . . . . .601.3.3, 1501.9 – 1501.9.2,
1506.0 – 1506.3
System changes . . . . . . . . . . . . . . . . . . . . . . . . .1506.3
Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1501.1.1
OPEN TRENCH WORK . . . . . . . . . . . . . . . . . . . . . . . .314.3
OPENING, EFFECTIVE,
DEFINITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .207.0
OSHPD 1R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .301.8
OVERFLOWS . . . . . . .404.2, 413.5, 607.5, 1603.9, 1603.9.1
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