Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS

(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.)

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.

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CHAPTER 16

NONPOTABLE RAINWATER CATCHMENT SYSTEMS

apply to the installation, construction, alteration, and repair of nonpotable rainwater catchment systems.

1601.1.1 Allowable Use of Alternate Water. Where approved or required by the Authority Having Jurisdiction, rainwater shall be permitted to be used instead of potable water for the applications identified in this chap ter.

be designed in accordance with this chapter by a person registered or licensed to perform plumbing design work or who demonstrates competency to design the rainwater catchment system as required by the Authority Having Jurisdiction . Components, piping, and fittings used in a rainwater catchment system shall be listed.

[HCD 1] Irrigation design plans shall meet the requirements of the California Code of Regulations, Title 23, Division 2, Chapter 2.7, Model Water Efficient Landscape Ordinance.

Exceptions:

(1) A person registered or licensed to perform plumbing design work is not required to design rainwater catchment systems used for irrigation with a maximum storage capacity of 360 gallons (1363 L).

(2) A person registered or licensed to perform plumbing design work is not required to design rainwater catchment systems for single family dwellings where outlets, piping, and system components are located on the exterior of the building.

install, alter, or cause to be constructed, installed, or altered a nonpotable rainwater catchment system in a building or on a premise without first obtaining a permit to do such work from the Authority Having Jurisdiction.

Exceptions:

(1) A permit is not required for exterior rainwater catchment systems used for outdoor non-spray irrigation with a maximum storage capacity of 5000 gallons (18 927 L) where the tank is supported directly upon grade and the ratio of height to diameter or width does not exceed 2 to 1 and it does not require electrical power or a makeup water supply connection. (2) [HCD 1 & HCD 2] A permit is not required for exterior rainwater catchment systems used for spray irrigation with a maximum storage capacity of 360 gallons (1363 L).

shall be properly identified as to the manufacturer.

Rainwater catchment systems and components shall be inspected and maintained in accordance with with the manufacturer’s recommendations and/or as required by the enforcing agency .

TABLE 1601.5 MINIMUM ALTERNATE WATER SOURCE TESTING, INSPECTION, AND MAINTENANCE FREQUENCY

• The cross-connection test shall be performed in the presence of the Authority Having Jurisdiction in accordance with the requirements of this chapter.

1601.5.1 Maintenance Responsibility. The required maintenance and inspection of rainwater catchment systems shall be the responsibility of the property owner unless otherwise required by the Authority Having Jurisdiction.

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NONPOTABLE RAINWATER CATCHMENT SYSTEMS

An operation and maintenance manual for rainwater catchment systems required to have a permit in accordance with Section 1601.3, shall be supplied to the building owner by the system designer or installer . The operating and maintenance manual shall include the following:

(1) Diagram(s) of the entire system and the location of system components.

(2) Instructions for operating and maintaining the system.

(3) Instructions on maintaining the required water quality as for rainwater catchment systems .

(4) Details startup, shutdown, and deactivating the system for maintenance, repair, or other purposes.

(5) Applicable testing, inspection, and maintenance frequencies in accordance with Section 1601.5.

(6) A method of contacting the installer and/or manufacturer(s).

(7) Directions to the owner or occupant that the manual shall remain with the building throughout the life cycle of the structure.

minimum water quality for rainwater catchment systems shall comply with the applicable water quality requirements for the intended application as determined by the Authority Having Jurisdiction. Water quality for nonpotable rainwater catchment systems shall comply with Section 1603.4. In the absence of water quality requirements for harvested rainwa- ter, Table 1603.4 shall apply.

Exceptions:

(1) Water treatment is not required for rainwater catchment systems used for aboveground irrigation with a maximum storage capacity of 360 gallons (1363 L).

(2) Water treatment is not required for rainwater catchment systems used for surface, subsurface or drip irrigation.

Rainwater catchment systems shall be constructed of materials that are compatible with the type of pipe and fitting materials, water treatment, and water conditions in the system.

other devices that contain mercury that come in contact with rainwater supply shall not be permitted.

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.

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.

Unless otherwise provided for in this chapter, rainwater catchment piping shall be sized in accordance with Chapter 6 for sizing potable water piping.

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.

rainwater catchment system shall be issued until complete plumbing plans, with data satisfactory to the Authority Having Jurisdiction, have been submitted and approved.

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.

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.

of a rainwater catchment system is installed within a building, a cross-connection test is required in accordance with Section 1605.3. 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.

The design and size of rainwater drains, gutters, conductors, and leaders shall comply with Chapter 11 of this code.

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NONPOTABLE RAINWATER CATCHMENT SYSTEMS

Rain- 1603.3 Rainwater Catchment Collection Surfaces. water catchment system materials shall comply with Section Rainwater shall be collected from roof surfaces or other 1602.7.1 through Section 1602.7.3 . impervious manmade, aboveground collection surfaces. 1602.7.1 Water Supply and Distribution Materi- 1603.3.1 Other Surfaces. Natural precipitation colals. Rainwater catchment water supply and distribution lected from surface water runoff, vehicular parking surmaterials shall comply with the requirements of this code faces, or manmade surfaces at or below grade shall be in for potable water supply and distribution systems unless accordance with the water quality requirements for onotherwise provided for in this section. 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.

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

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 .

collected rainwater requires disinfection or other treat-

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-

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.

shall comply with IAPMO/ANSI Z1002 and be installed in accordance with Section 1603.6 through Section 1603.12.

Rainwater storage tanks shall be permitted to be installed above or below grade.

of an opaque material, approved for aboveground use in direct sunlight or shall be shielded from direct sunlight. Tanks shall be installed in an accessible location to allow for inspection and cleaning. The tank shall be installed on a foundation or platform that is constructed to accommodate loads in accordance with the California Building Code .

Exception: Tanks may be installed directly on grade in accor- dance with Section 1601.3.

FIGURE 1603.2 1603.8 Below Grade. Rainwater storage tanks installed below grade shall be structurally designed to withstand antic

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NONPOTABLE RAINWATER CATCHMENT SYSTEMS

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TABLE 1603.4

MINIMUM WATER QUALITY

For SI units: 1 micron = 1 µm, 1 gallon = 3.785 L

ipated earth or other loads. Holding tank covers shall be capable of supporting an earth load of not less than 300 pounds per square foot (lb/ft [2] ) (1465 kg/m [2] ) where the tank is designed for underground installation. Below grade rainwater tanks installed underground shall be provided with manholes. Below grade storage tanks, located outside of the building, shall be provided with either a manhole not less than 24 inches (610 mm) square or a manhole with an inside diameter of not less than 24 inches (610 mm). Service ports in manhole cov- ers shall be not less than 8 inches (203 mm) in diameter. The manhole opening shall be not less than 20 inches (508 mm) in diameter and located not less than 4 inches (102 mm) above

the surrounding grade. The surrounding grade shall be sloped away from the manhole. Underground tanks shall be ballasted, anchored, or otherwise secured, to prevent the tank from floating out of the ground where empty. The combined weight of the tank and hold down system shall meet or exceed the buoyancy force of the tank.

shall be provided with a means of draining and cleaning. The overflow drain shall not be equipped with a shutoff valve. The overflow outlet shall discharge in accordance with this code for storm drainage systems. Where discharging to the storm drainage system, the overflow drain and tank drain shall be protected from backflow of the storm drainage system by a backwater valve or other approved method. Back- water valves shall be installed so that access is provided to the working parts for service and repair.

1603.9.1 Overflow Outlet Size. The overflow outlet

shall be sized to accommodate the flow of the rainwater

entering the tank and not less than the aggregate crosssectional area of inflow pipes.

tank openings shall be protected to prevent the entrance of insects, birds, or rodents into the tank and piping systems .

Rainwater tank access openings exceeding 12 inches (305 mm) in diameter shall be secured to prevent tampering and unintended entry by either a lockable device or other approved method.

(A) Animals and Insects. Screens installed on vent pipes, inlets, and overflow pipes shall have an aperture of not greater than [1] ∕ 16 of an inch (1.6 mm) and shall be close fit- ting.

(B) Human Access. A minimum of one access opening shall be provided to allow inspection and cleaning. Rainwater tank manholes and access openings shall be secured by either a lockable device or other approved method to pre- vent unauthorized access.

marked with the capacity and the language: “NONPOTABLE RAINWATER.” Where openings are provided to allow a person to enter the tank, the opening shall be marked with the following language: “DANGER-CONFINED SPACE.”

drainage or overflow piping is not provided or is considered insufficient, a vent shall be installed on each tank. The vent shall extend from the top of the tank and terminate not less than 6 inches (152 mm) above grade and shall be provided with a vent sized in accordance with this code, and based on the size of the influent pipe . The vent terminal shall be directed downward and covered with a [1] ∕ 16 of an inch ( 1.6 mm) mesh screen to prevent the entry of vermin and insects. Tank vent pipes shall not be connected to the sanitary drainage system vent.

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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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.

inspected and tested in accordance with Section 1605.2 and Section 1605.3.

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.

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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less than 15 pounds-force per square inch (psi) (103 kPa) residual pressure at the highest and most remote outlet served. Where the water pressure in the rainwater 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 in accordance with this code.

conductors, leaders, and gutters shall be designed and installed in accordance with this code.

Devices and equipment used to treat rainwater to maintain the minimum water quality requirements determined by the Authority Having Jurisdiction shall be listed or labeled (thirdparty certified) by a listing agency (accredited conformity assessment body) and approved for the intended application.

locations subject to freezing shall be provided with an approved means of freeze protection.

The rainwater catchment conveyance system shall be equipped with a debris excluder or other approved means to prevent the accumulation of leaves, needles, other debris and sediment from entering the storage tank. Devices or methods used to remove debris or sediment

shall be accessible and sized and installed in accordance with

manufacturer’s installation instructions.

of particulates not larger than 100 microns (100 µm) shall be provided for rainwater supplied to water closets, urinals, trap primers, and drip irrigation system s .

slope and be sized in accordance with Section 1103.3.

Rainwater diversion valves ranging from 2 inches (50 mm) through 12 inches (300 mm) in diameter shall be an approved diverter valve . Valves shall be readily accessible and include a filter located upstream of the valve when required.

in accordance with Section 1604.2 and Section 1604.3 , and applicable requirements of the California Building Code .

idential Restroom Signs. A sign shall be installed in restrooms in commercial, industrial, and institutional occupancies , and in residential common use areas using nonpotable rainwater for water closets, urinals, or both. Signs shall comply with all applicable requirements of the Califor- nia Building Code. Each sign shall contain the following text:

TO CONSERVE WATER, THIS BUILDING USES RAINWATER TO FLUSH TOILETS AND URINALS.

containing nonpotable rainwater equipment shall have a sign posted with the following wording in 1 inch (25.4 mm) let ters:

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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.

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