Tap Water Filtration
Install tap-water filtration appropriate to local water-quality conditions.
Spec
Applies uniformly from Gold upward.
Scope
The primary drinking-water tap (typically the kitchen sink cold tap). Whole-house filtration is acceptable but not required.
Requirements
- 01.
Obtain or request the local Consumer Confidence Report (CCR) from the water utility, or — for well water — perform a current water-quality test.
- 02.
Install a point-of-use or whole-house filtration system rated to remove the specific contaminants flagged in the CCR or well test.
- 03.
At minimum, the filter must hold an NSF/ANSI 42 certification (aesthetic — chlorine, taste, odor) for treated municipal water. NSF/ANSI 53 (health-related: lead, cysts, VOCs) or 401 (emerging contaminants) is required where those contaminants are present.
Documentation
Evidence the inspector / Institute will need.
- 01.
Copy of the CCR or well water-quality test results highlighting contaminants of concern.
- 02.
Filter specification sheet showing matching NSF/ANSI certifications.
- 03.
Photo of installed filter with model number visible.
Guidance
Reading a CCR
Every U.S. public water utility publishes an annual Consumer Confidence Report listing detected contaminants and their levels relative to the MCL (maximum contaminant level). Items at or near MCL — especially lead, chromium-6, nitrates, disinfection byproducts (TTHMs), PFAS — should drive the filter selection.
Filter types
Pitcher / faucet-mount filters meet the spirit of the requirement only if certified for the specific contaminants. Under-sink activated-carbon block units (e.g. Multipure, AquaTru, Berkey countertop) are typically the highest-performing point-of-use option. Whole-house systems are appropriate only for chlorine and sediment — they do not effectively remove dissolved metals or PFAS.
Resources
- NSF / ANSI Standard 53 — Health Effects →
Lookup of which filters are certified for which contaminants.
- EWG Tap Water Database →
Independent database of utility CCRs with plain-language contaminant explanations.
Note
Filter cartridges have a finite life — typically 6-12 months for carbon, 5-10 years for reverse osmosis membranes. Document the replacement cadence in the building maintenance instructions.