Changes being proposed in this third review, based on previous input, include:

• Clarifications made to definitions in Section 3, Definition of Terms, plus a new term was defined.

• Clarifications made to Section 5, Risk Characterization. Those changes were substantive because building characteristics were reorganized into two subsections for clarity, subsections 5.2 and 5.3.

• Reorganization of Table 1, Determining Preventative Measures Required for Buildings. The improvements reference two subsections of Section 5 (Sec 5.2 and 5.3).

• Creation of a new subsection, 7.4, Water System Treatment and Management Program, in Section 7. Commenters indicated there should be specifications for a “water system treatment and management program” for buildings with none of the risk characteristics (now listed in Sec 5.2) but with any of the equipment specified (now listed in Sec 5.3).

• Clarifications to Section 8 regarding wording, references, cited regulations, and informative notes.

Compliance with the standard requires facility managers/owners to formally take responsibility for controlling Legionella in their building water systems, while at the same time acts as a defense against accusations of negligence in those cases which are caused by a hazard from unknown sources.

Standard 188P also covers the potable water system in buildings, which are not treated as often as cooling towers, and will hold facility managers/owners accountable for properly managing the entire building water system both potable and utility water.

The standard differs from ASHRAE Guideline 12, Minimizing the Risk of Legionellosis Associated with Building Water Systems, in that while the guideline gives recommendations about how to treat various building water systems, the standard specifies the practice of exactly what must be done with all those recommendations.

For more information and to comment, visit www.ashrae.org/publicreviews.

Publication date: 2/11/2013