Water treatment

Water treatment


To improve water quality by requiring the use of water treatment systems.

Yes, water used for fire protection falls under the scope of the Legionella management plan and must be considered as part of the hazard analysis. Systems with cross-connection between the fire protection system and the main potable water supply do increase Legionella growth risk, whereas systems that include backflow prevention into the main drinking water supply likely carry lower risk. Projects must assess all applicable systems and determine the appropriate level of risk.

No, Feature 36, Part 5 requires all project teams to have a legionella control plan in place, even if no cooling towers are present. It is possible for a low-risk project to implement a streamlined plan representative of the risk level at the project building. Besides cooling towers, other assets to consider may include evaporative condensers, domestic hot and cold water systems, decorative fountains, shower heads and anywhere else that could generate water aerosols.

The WELL feature does not require a specific NSF-rating, as long as it is a filter rated by the NSF to remove or reduce microbial cysts. The words "cyst reduction" or "cyst removal" should be present on the product label information. Filters that have an absolute pore size of 1 micron or smaller would also be accepted. The manufacturer should be able to provide this information. Note that NSF Standards 42, 53, and 58 can be applied to many contaminants, and thus simply a product's certification under one of these standards does not automatically indicate cyst removal/reduction or relevance to this feature.