A fourth version of ASHRAE’s proposed legionellosis standard is open for public comment until November 10, 2014.

Standard 188P, Legionellosis: Risk Management for Building Water Systems, currently under development, will establish minimum legionellosis risk management requirements for building water systems. The standard is intended for use by building owners and managers and those involved in the design, construction, installation, commissioning, operation, maintenance and service of centralized building water systems and components.

The draft of the document and instructions on submitting comments can be found at  www.ashrae.org/publicreviews. The proposed standard will be available for access until Nov. 10, 2014.

Changes to the proposed standard since its last public review in January 2013 include:
• Alignment of the document with the revised title, purpose and scope.
• Removal of hazard analysis and critical control points (HACCP) terminology; some of the principles of the HACCP process are consistent with the process utilized in the document.
• Inclusion of a normative appendix for health care facilities meeting specific requirements that provides an alternate compliance path that is more stringent than for other facilities.
• More emphasis on requirements for design, construction, installation, commissioning, operation, maintenance and service.

Tom Watson, chair of the Standard 188P committee, notes that the standard contains both normative sections and appendices that specify what is required to comply. It also contains informative appendices and references as guidance about how to do things that may be necessary for a given building water system.

“Building water systems vary substantially in their design and their capability for transmission of Legionella,” Watson said. “Scientific evidence is either lacking or inconclusive in certain aspects of Legionella control. The informative guidance is included to provide suggestions, recommendations and references.”