Source and time boundary
We analyze an EPA WaterSense bulk-directory snapshot saved on 30 October 2026. The site's source version is fixed: refreshing a page does not refresh certification status. The official product search is the place to check a current listing.
Rows, identities and names are different denominators
The saved raw category files contain 18,544 showerhead rows, 22,471 lavatory faucet rows and 6,793 tank-type toilet rows. The normalized accepted populations used here are 17,993, 21,063 and 6,591 identities. Duplicate and conflicting source rows are handled by the versioned import rules; rejected rows are not silently counted as products. We retain literal model strings, including wildcard text, without expanding possible models.
A repeated model name does not merge two product identities. Counts are always category-specific. The same brand appearing in multiple categories does not establish an installation relationship.
Units and composite values
GPM means US gallons per minute. GPF means US gallons per flush. A numeric rating is usable only with its field and unit. Dual-flush values retain full and reduced modes; a missing component is not zero. Program test requirements provide context but do not replace model-specific reports.
What is calculated
Distribution counts are grouped from accepted identities in the fixed snapshot. Percentages use the stated category denominator and are rounded to two decimals. They are not sales shares. Household estimates multiply explicit ratings by time or use counts. UNKNOWN values are excluded from numeric calculations, with their count stated.
Evidence and rights boundary
Each normalized field retains its source identity and raw-file locator in our research records. Our research contains factual values, our derived counts and original explanations, with EPA attribution. They do not reuse manufacturer images, manuals or promotional text, EPA seals, the WaterSense logo or certification labels.
EPA's WaterSense FAQ permits public use of its published content. Its mark rules are separate. We make no claim of partnership, EPA approval, current product certification, price, availability or installation compatibility.
Source: EPA WaterSense product directory, saved 30 October 2026; this analysis uses the fixed catalog release described in Sources and research methods. These historical observations do not establish current certification or product availability. Fixture Flow Atlas is independent of EPA; no affiliation or endorsement is claimed.