PRESS RELEASE

    2023 IAPMO Water Efficiency and Sanitation Standard Now Available

    2023 IAPMO Water Efficiency and Sanitation Standard Now Available

    Ontario, Calif. — 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

    ARCSA International Announces Technical Symposium Event for May 2026

    12 November 2025

    ARCSA International will host a new Technical Symposium May 20–21, 2026, at Grundfos Headquarters in Brookshire, Texas. This two-day event will feature advanced training, industry updates, technology displays, and networking opportunities, with full program details coming later this year.

    Pacific Institute Report Recommends IAPMO’s Water Demand Calculator as a Key Strategy for National Water Efficiency

    04 November 2025

    Ontario, California — IAPMO®, a global team of experts engaging industry and government for a safer built environment, is proud to announce that its Water Demand Calculator® has been featured as a key recommendation in the Pacific Institute’s new landmark report, “Untapped Potential: An Assessment of Municipal and Industrial Water Efficiency Potential in the United States.”

    Blueprint for Progress: IAPMO at the ANSI Innovation Summit Demonstrates How Codes and Standards Advance U.S. Competitiveness and Public Health

    21 October 2025

    IAPMO® is proud to be a diamond sponsor and administrating organization at the 2025 ANSI Innovation Summit this week. Formerly World Standards Week, the ANSI Innovation Summit is an annual event that convenes the Institute's members and private- and public-sector stakeholders from across the standards and conformity assessment communities to come together, learn from each other, and showcase their important work. 

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