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

Water treatment

There are many types of contaminants that may compromise water quality, from pathogens and heavy metals to pesticide and herbicide residues. While routine testing helps to keep track of potential pollutants, sampling alone cannot guarantee the elimination of all risk. Disruptions to water supply, droughts, flooding and construction and infrastructure changes can temporarily affect water quality. Therefore, implementing and maintaining appropriate water filters is key in order to continuously deliver high quality water.

This feature prescribes technologies designed to maintain high water quality irrespective of variations to the water supply through the provisioning of various precautionary filtration and sterilization processes. Options include carbon filters, sediment filters and UV sanitization.

Part 1: Organic Chemical Removal

All water being delivered to the project area for human consumption or showers/baths is treated with the following:

a.187 Activated carbon filter.
Part 2: Sediment Filter

All water being delivered to the project area for human consumption or showers/baths is treated with the following:

a. Filter rated to remove suspended solids.
Part 3: Microbial Elimination

All water being delivered to the project area for human consumption or showers/baths is treated with one of the following:

a.188 UVGI water sanitation.
b. NSF filter rated to remove microbial cysts.
Part 4: Water Quality Maintenance

To verify that the selected filtration/sanitation system chosen continues to operate as designed, projects must annually provide the IWBI with:

a. Record-keeping for a minimum of 3 years, including evidence that the filter and/or sanitizer has been properly maintained as per the manufacturer's recommendation.
Part 5: Legionella Control

A point-by-point narrative describes how the building addresses Legionella, and includes the following:

a.177 Formation of a team for legionella management in the building.
b.177 Water system inventory and production of process flow diagrams.
c.177 Hazard analysis of water assets.
d.177 Identification of critical control points.
e.177 Maintenance and control m​easures, monitoring, establishment of performance limits and corrective actions.
f.177 Documentation, verification and validation procedures.

Applicability Matrix

Core & Shell New & Existing Buildings New & Existing Interiors
Part 1: Organic Chemical Removal O O O
Part 2: Sediment Filter O O O
Part 3: Microbial Elimination O O O
Part 4: Water Quality Maintenance O O O
Part 5: Legionella Control O O O
Commercial Kitchen Education Multifamily Residential Restaurant Retail
Part 1: Organic Chemical Removal O O O O O
Part 2: Sediment Filter O O O O O
Part 3: Microbial Elimination O O O O O
Part 4: Water Quality Maintenance O O O O O
Part 5: Legionella Control O O O O O

Verification Methods Matrix

Letters of Assurance Annotated Documents On-Site Checks
Part 1: Organic Chemical Removal MEP Spot Check
Part 2: Sediment Filter MEP Spot Check
Part 3: Microbial Elimination MEP Spot Check
Part 4: Water Quality Maintenance Operations Schedule
Part 5: Legionella Control Professional Narrative
177

ASHRAE. Proposed New Standard 188, Prevention of Legionellosis Associated with Building Water Systems. Atlanta, GA: ASHRAE; Jun, 2011. BSR/ASHRAE Standard 188P.

36.5.b

ASHRAE's proposed Hazard Analysis and Critical Control Point Plan requires teams to develop at least two process flow diagrams mapping the receipt, processing and delivery of water to occupants.

36.5.c

ASHRAE's proposed Hazard Analysis and Critical Control Point plan for preventing building associated legionellosis includes conducting a hazard analysis.

36.5.d

ASHRAE's proposed Hazard Analysis ad Critical Control Point plan includes identifying critical control points.

36.5.e

ASHRAE's Hazard Analysis and Critical Control Point plan for preventing building associated legionellosis includes monitoring identified control points and establishing procedures for corrective measures.

36.5.f

ASHRAE's proposed Hazard Analysis and Critical Control Point plan for preventing building-associated legionellosis includes establishing documentation and verification procedures.

36.5.a

ASHRAE's proposed Hazard Analysis and Critical Control Point Plan requires the development of a team comprised of members who understand the building's water systems and the principles of the plan.

187

Minnesota Department of Health. Water Treatment Using Carbon Filters (GAC). http://www.health.state.mn.us/divs/eh/hazardous/topics/gac1.pdf. Published 2013. Accessed June 10, 2015.

36.1.a

The Minnesota Department of Health notes that "A filter with granular activated carbon (GAC) is a proven option to remove certain chemicals, particularly organic chemicals, from water".

188

United States Environmental Protection Agency Office of Water. Alternative Disinfectants and Oxidants Guidance Manual. http://www.epa.gov/ogwdw/mdbp/alternative_disinfectants_guidance.pdf. Published April 1999. Accessed June 12, 2015.

36.3.a

The US EPA's Alternative Disinfectants and Oxidants Guidance Manual notes that the optimum UV range is between 245 and 285 nm, which corresponds to UV-C radiation (200-280 nm).