Changes clarifying requirements in proposed ASHRAE Standard 188P, Prevention of Legionellosis Associated With Building Water Systems, are open for a third public comment ending March 11.

William McCoy, chair of the Standard 188P committee, said more than 150 comments were received during the previous review, in June 2011. Resulting changes include the:

• Clarification of definitions and the addition of a definition in Section 3, Definition of Terms.

• Reorganization of building characteristics into two subsections—subsections 5.2 and 5.3—for clarity in Section 5, Risk Characterization.

• Reorganization of Table 1, Determining Preventative Measures Required for Buildings, with two subsections of Section 5 (5.2 and 5.3) referenced.

• Creation of a new subsection—7.4, Water System Treatment and Management Program—in Section 7.

• Clarification of wording, references, cited regulations, and informative notes in Section 8.

Standard 188P also covers potable-water systems in buildings.

Standard 188P differs from ASHRAE Guideline 12, Minimizing the Risk of Legionellosis Associated With Building Water Systems, in that it specifies exactly what must be done to treat various building water systems, while the guideline merely gives recommendations.

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