Ontario, Calif. (July 15, 2024) — The International Association of Plumbing and Mechanical Officials (IAPMO®) has published the 2023 edition of the Water Efficiency and Sanitation Standard (WE•Stand) in both hardcopy and electronic versions, completing a three-year consensus development cycle accredited by the American National Standards Institute (ANSI). This publication can be purchased through the IAPMO web store at the following URL: https://iapmostore.org/.

The WE•Stand is developed by IAPMO to provide comprehensive requirements for optimizing water use practices attributed to the built environment while maintaining protection of the public health, safety and welfare. The 2023 WE•Stand embodies the latest advancements in water conservation practices within the built environment. 

Key provisions of the 2023 WE•Stand and changes from the 2020 edition include:

• New permitting requirements addressing applications; construction documents; exempt work; inspections and testing; violations and penalties; and appeals
• New requirements for alternative engineered designs
• New requirements for identification of potable and nonpotable water systems
• Updated maximum flow rates for fixture fittings
• New listing requirements for water treatment systems
• New water meter performance specifications
• Updated requirements for landscape design and installation including documentation; plant and irrigation system limitations; irrigation control systems; zone performance criteria; audits; and sprinklers
• Updated requirements and examples for the Water Demand Calculator
• Updated ecological-sanitation system provisions addressing operation and maintenance manuals; sizing of urine storage tanks; and treatment and application of stored urine
• New Chapter 9 for the design, installation, construction, and maintenance of onsite gray water treatment systems for non-potable reuse
• New requirements for determining the maximum hot water system ratio in dwelling units
• Updated requirements for potable rainwater catchment systems addressing minimum water quality; maintenance and testing; collection surfaces; and drainage materials
• New Appendix E for the design and installation of onsite wastewater treatment systems for direct potable water use in dwelling units
• New Appendix F for the design and installation of gray water drainage systems in new construction, additions, and retrofits to allow for future connections to gray water irrigation or reuse systems
• New Appendix G for water efficiency ratings applicable to residential properties containing single-family dwellings

In 2020, IAPMO’s WE•Stand was published as an American National Standard, replacing the Green Plumbing and Mechanical Code Supplement. The 2023 WE•Stand represents the second edition to be developed via the ANSI-accredited consensus process.

For questions about the WE•Stand, please contact Taylor Duran at (909) 218-8126 or taylor.duran@iapmo.org.