This is a legacy version of the WELL Building Standard. Please check the latest version here.

Water treatment

Water treatment


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

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.