CSA B805:22/ICC 805:2022 Rainwater harvesting systems

The second edition of the CSA B805/ICC 805-2022 rainwater harvesting systems standard, is now available. 

Changes included in the 2022 edition include:

• updated referenced standards;
• definitions for “bypass system” and “make-up system”;
• changed filtration requirements for UV disinfection systems; 
• and more.

This Standard addresses roof surface rainwater and stormwater (i.e., rainwater that has come in contact with the ground or a green roof) being used as source water. This Standard addresses rainwater intended for use in non-potable applications (e.g., irrigation, fire protection, toilet and urinal flushing, clothes washing, hose bibbs, decorative fountains, and vehicle washing) as well potable applications (e.g., human consumption, oral care, food preparation, dishwashing, and bathing). The term “rainwater harvesting” is used generically in this Standard and can refer to harvesting of either roof runoff or stormwater runoff.

1.1.1 Applicability The provisions of this Standard apply to the design, materials, installation, and operation of rainwater harvesting systems for potable and non-potable applications

1.1.2 Source waters This Standard covers the use of rainwater and stormwater as the source water.

Note: Rainwater includes all forms of water from natural precipitation including but not limited to rain, snowmelt, etc. The term “rainwater harvesting” is used generically in this Standard and can refer to harvesting of either roof runoff or stormwater.

1.1.3 Applications This Standard covers rainwater harvesting systems that provide water for single-family residential applications; multi-residential applications; and non-residential applications.

1.2 Exclusions This Standard does not cover rainwater harvesting systems that provide water for process water systems for industrial or manufacturing purposes; and water distribution systems for commercial agricultural processes; and collection of surface water.