Appendix Q — INDOOR HORTICULTURAL FACILITIES — 2025 California Plumbing Code (Title 24, Part 5)

(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.)

Adopting Agency	BSC	BSC- CG	SFM	HCD			DSA			OSHPD							BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
Adopting Agency	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
Adopt Entire Chapter
Adopt Entire Chapter as amended (amended sections listed below)
Adopt only those sections that are listed below
Chapter/Section

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.

540 2025 CALIFORNIA PLUMBING CODE

APPENDIX Q

INDOOR HORTICULTURAL FACILITIES

The provisions contained in this appendix are not mandatory unless specifically adopted by a state agency, or referenced in the adopting ordinance.

Q 101.0 Indoor Horticultural Facilities.

Q 101.1 General. Plumbing for indoor horticulture facilities shall be in accordance with this code. This appendix shall apply to primary and secondary horticulture facilities.

Q 201.0 Definitions.

Q 201.1 General. For the purpose of this appendix, the following definitions shall apply: Agricultural Water. Water used in indoor horticulture activities where water is intended to contact plants. Cultivation Room. A room of any size where plants are grown under controlled conditions. Also known as a grow room. Fertigation. The process of adding nutrients into the irrigation water.

Q 201.1 General.* For the purpose of this appendix, the following definitions shall apply: Agricultural Water. Water used in indoor horticulture activities where water is intended to contact plants. Cultivation Room. A room of any size where plants are grown under controlled conditions. Also known as a grow room. Fertigation. The process of adding nutrients into the irrigation water.

Horticulture Facility. A business, facility, or establishment where indoor horticulture is grown, cultivated, dried, extracted, weighed, packaged, or processed. Indoor Horticulture. The cultivation and processing of plants in an indoor space. Indoor Horticulture Water Distribution Systems. A system to supply water from its primary source to its point of use, including but not limited to pipes, sprinklers, irrigation equipment, pumps, valves, storage tanks, meters, and fittings. Nutrient. Substances, chemicals, or ingredients used to promote growth, provide energy, and/or sustain plants. Plant. A multicellular organism having cellulose cell walls intended for human consumption, ingestion, inhalation, or topical application. Primary Horticulture Facility. A facility devoted to the growing and/or harvesting of plants. Cultivation rooms are located within these facilities.

Secondary Horticulture Facility. A facility devoted to harvesting (such as hulling or shelling), packing, and/or holding of plants.

Q 301.0 Classification of Facilities.

Q 301.1 General. Facilities used for indoor horticultural cultivation and processing shall be in accordance with the applicable codes as mandated by the Authority Having Jurisdiction. Q 301.2 Approved Locations. Facilities used for indoor horticultural cultivation and processing shall be located in accordance with the building code and the Authority Having Jurisdiction.

Q 401.0 Documentation.

Q 401.1 General. Documentation for permitting shall be provided in accordance with the requirements of Section 104.0 and the Authority Having Jurisdiction. The documen

tation shall show compliance with this section and other requirements in accordance with the Authority Having Jurisdiction.

Q 501.0 General.

Q 501.1 Mechanical Systems. Indoor horticulture mechanical systems shall be in accordance with the mechanical code.

Q 501.2 Fire Suppression Systems. Fire suppression systems shall be in accordance with the building code and fire code.

Q 501.3 Emergency Eyewash and Shower Equip- ment. Emergency shower and eyewash equipment shall be required in accordance with Section 416.0.

Q 601.0 Water Supply. Q 601.1 General. Indoor horticulture water distribution systems shall be supplied with potable water in accordance with Chapter 6. Q 601.2 Materials. Pipe, tube, and fitting materials in contact with potable water, drinking water, or both shall be in accordance with Section 604.0.

Q 601.3 Protection. Potable water piping used for irrigation purposes shall be equipped with an approved backflow prevention device or assembly in accordance with Table 603.2.

Q 601.4 Alternate Water Supply. Where permitted, agricultural water may be used or alternate water sources in accordance with Appendix K.

Q 701.0 Storage Tanks. Q 701.1 Construction. Where storage tanks are used, they shall be approved by the Authority Having Jurisdiction. Potable water storage tanks shall comply with Section 607.0. Rainwater catchment storage tanks shall comply with Appendix K or in accordance with the Authority Having Jurisdiction.

Q 801.0 Fertigation and Irrigation Equipment. Q 801.1 Installation. Nutrient tanks and irrigation equipment shall be installed in accordance with the manufacturer’s instructions. When connected to the potable water supply, tanks and irrigation equipment shall be located downstream of water storage tank and be protected by an approved backflow device or method in accordance with Table 603.2

Q 801.2 Materials and Construction. The piping, components, and devices shall be compatible with the additives or nutrients used. Above grade storage tanks shall be of an opaque material, approved for aboveground use in direct sunlight, or shall be shielded from direct sunlight.

APPENDIX Q

Q 901.0 Sanitary Drainage and Indirect Wastes. Q 901.1 General. Sanitary drainage shall be in accordance with Chapter 7. Indirect wastes shall be in accordance with Chapter 8. The drainage system shall be compatible with the discharge liquid waste.

Q 901.2 Hazardous Materials. Hazardous materials shall not be discharged into the sanitary sewer, storm drain, or on the ground. Q 901.3 Agricultural Water Waste. Agricultural water shall be discharged in accordance with the local, state, and federal regulations as approved by the Authority Having Jurisdiction. Where agricultural water discharges to the outdoors, and is not connected to the sanitary sewer, the piping shall be installed as to restrict rodents or vermin from entering the building. Q 901.4 Floor Drains, Floor Sinks, and Receptors. Wastewater shall discharge into an approved receptor. Receptors shall be compatible with the wastewater and installed in accordance with this code.

Q 901.4.1 Plant Storage Areas. Where drains are provided in spaces where plants are stored, such drains shall be installed with indirect waste piping. Each indirect waste pipe from plant storage areas shall be separately piped to the indirect waste receptor and shall not combine with other indirect waste pipes.

Q 1001.0 Facilities.

Q 1001.1 Toilet Facilities. Toilet facilities shall be provided in accordance with the occupancy type.

Q 1001.2 Location. Toilet facilities shall be located in such a manner to prevent contamination of plants during harvesting, holding, manufacturing/processing, and packing.

542 2025 CALIFORNIA PLUMBING CODE

CALIFORNIA PLUMBING CODE – MATRIX ADOPTION TABLE