By Richard Grace

In early 2018, the Canadian Standards Association (CSA) in conjunction with the International Code Council (ICC) produced a national standard, CSA B805-18/ICC 805-2018, that could be used to assist in the design for rainwater harvesting systems. This standard has been accepted by reference in the 2021 International Plumbing Code for non-potable water system use. It provides prescriptive and performance requirements and includes provisions for multiple collection surfaces and various end uses.

For larger commercial and multifamily buildings that may have problems complying with minimum rainwater provisions in the Virginia Plumbing Code, designers may submit a request to utilize this alternative method with their proposed rainwater harvesting system. If designing to the CSA B805-18/ICC 805-2018 standard, the designer must clearly show how the proposed system complies with the requirements of the chosen compliance path defined in the standard.