The approved Standard 188, as with previous 188P public review drafts, outlines a strategy for reducing the risk of legionellosis associated with building water systems by implementing a plan for managing the building water systems. Drafts 1-3 called it a HACCP (Hazard Analysis and Critical Control Point) plan. In Draft 4, HACCP components were entirely retained but given generic terms and the plan was renamed simply a “Water Management Program” (Program​).

The approved Standard requires at a minimum building owners to have and practice a Program for facilities with:

  • Cooling towers or evaporative condensers,
  • Whirlpool spas,
  • Ornamental fountains,
  • Misters, atomizers, air washers, humidifiers, or
  • Cooling towers or evaporative condensers,

... And, for potable (domestic) plumbing systems if a building has:

  • Multiple housing units with a centralized hot water system,
  • More than ten stories,
  • Housing for occupants over the age of 65,
  • Patients staying longer than 24 hours, or
  • An area housing or treating people with certain health factors.

The written document for the Water Management Program must include the following:

1. A list of the water management program team members. The team should consist of the key individuals who will oversee the Program and make decisions about it. Others may be needed to implement the Program.

2. A brief description of the building water systems, with flow diagrams, listing salient information about all the building water systems and show, in simple line diagrams, where water is received, processed, and used. For most facilities, at least two diagrams should be included, one for domestic (potable) water systems and another for utility (non-potable) systems. Flow diagrams should be simple. Cluttering them with unnecessary details will only hinder their primary purpose.

3. A (Legionella) Hazard Analysis of Building Water Systems. In the analysis, a brief explanation is given as to why each water system does or does not present a significant potential for Legionella growth and transmission and, for those that do, whether it is a location at which Legionella control measures can be applied.

4. (Legionella) Hazard Control Measures. This is the most important part of any Legionella water management plan because control measures are what actually reduce the risk of Legionnaires’ disease. If effective control measures are not selected, the Program will fail to sufficiently reduce Legionella risk.