ARCSA International is pleased to announce the United States General Services Administration (GSA) has accepted its proposed change for the Facilities Standards for the Public Buildings Service (P100), requiring major capital projects of more than 5,000 square feet employing rooftop rainwater catchment and harvesting systems to comply with relevant ARCSA/ASPE/ANSI standards.

P100, which is updated every three years, establishes mandatory design standards and performance criteria for GSA-owned buildings. Design and construction professionals must abide by the policy and technical criteria in P100 while programming, designing, and documenting GSA buildings.

ARCSA International submitted the proposal in fall 2023. Proposals were reviewed by a technical committee, the P100 Steering Committee, the GSA Regions and PBS business lines. GSA officially released the 2024 P100 on May 31, and it may be found at www.gsa.gov/p100.

The new language, which is in Section 2.5.3.2 WATER USE, reads as follows:

All major capital projects, with a scope of site work exceeding 5000sf, are required to comply with the equivalent of SITES prerequisite 3.2 to ‘Reduce Water Use for Landscape Irrigation’ and credit 3.4 to significantly ‘Reduce Outdoor Water Use’ for a minimum of 5 points. The goal of this requirement is to protect and conserve water. Where SITES certification is not being pursued, design submissions must follow SITES certification procedures for approach and documentation of this element. 

Rainwater catchment and harvesting systems from architectural rooftops must comply with ARCSA/ASPE/ANSI Standard 63-2020: Rainwater Catchment Systems, while systems harvesting sidewalk, plaza, and/ or parking lot runoff must comply with ARCSA/ASPE/ANSI 78: Stormwater Harvesting System Design for Direct End-Use Applications. In addition to the above, capital projects may use recycled water sourced from a centralized treatment facility to meet these requirements. Testing of the recycled water must be conducted to determine if the chemistry is compatible for sustaining the proposed plant palette. Utilize EPA REUSExplorer Tool for State and local requirements for water reuse. CxP to confirm installed features are functioning as per design and Facility Managers are trained.

“ARCSA International has been working to expand our reach and provide our rainwater and stormwater design standards to the public via the Uniform Plumbing Code (UPC), the EPA WRAP Action, and through the Facilities Standards for the Public Buildings Service (P100),” ARCSA International Executive Director Heather Kinkade said. “We are extremely pleased that we have been successful in all these efforts and will continue to offer our professional design assistance and rainwater catchment personnel training where we can.”

ARCSA International, which joined IAPMO in September 2023, provides resources and information on rainwater and stormwater collection to promote the advancement of rainwater conservation and to work with government at all levels in promoting rainwater and stormwater management. For more information, visit www.arcsa.org.