Lead removal mostly held up beyond the rated capacity in the studies we found, but PFAS removal can drop within or after the rated life. We found no US survey that measures how late people change cartridges, so our calculator shows late replacement as a scenario, not as a fact.
| Source | What it found (quoted) and its limits | Evidence |
|---|---|---|
| Purchase JM, Rouillier R, Pieper KJ, Edwards M. Understanding Failure Modes of NSF/ANSI 53 Lead-Certified Point-of-Use Pitcher and Faucet Filters. Environ. Sci. Technol. Lett. 8:155-160 (2021) · new peer-reviewed lab study |
Beyond rated capacity "a relatively high percentage of lead removal (>71%) was almost always maintained"; "50% of influent lead passing through some replicate POUs" (colloidal lead); brand B pitcher "clogged at 81% rated capacity"; soluble lead: all 288 effluent samples <3.7 ug/L Limits: Lab waters, 10 brands; extreme influent (up to ~1000 ug/L); not PFAS |
Evidence: strong Free to read · source · added 2026-10-30 |
| Herkert et al. 2020 (see C03), Table 1 average PFAS removal by device type (2020) · new peer-reviewed field sampling |
PFOA removal: RO ">92%", two-stage ">99%", pitcher "67%", faucet "84%", fridge "71%", whole-house GAC "19%"; whole-house: "saturated media in these larger activated carbon systems may be desorbing PFASs" Limits: In-use filters of unknown remaining life; one region; small n per type (2-22) |
Evidence: strong Access unknown · source · added 2026-10-30 |
| Purchase JM, Villalona C, Katner A, Pieper KJ, Edwards M. Household Point-of-Use Faucet Filters for Lead Removal: Field Performance and User Experiences. ACS ES&T Water 5(6):3045-3053 (2025) · new peer-reviewed field study |
ELA homes: "Most were replaced before 50% of the rated capacity."; "By this standard none of the filters in ELA reached the filter's capacity."; residents judged clogging at "average flow was 62% of its initial value"; NOLA flow reductions "of 16% on average"; "average POU removal efficiencies were 94.8% for Pb" Limits: Two Louisiana communities, faucet filters only, small n; clogging-driven not schedule-driven |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Teymoorian T, Dinh QT, Barbeau B, Sauve S. Performance of pitcher-type POU filters for the removal of 75 PFAS from drinking water. Front. Environ. Chem. 5:1376079 (2024) · new peer-reviewed lab+home study |
Volume-weighted total PFAS removal after 160 L: ZeroWater 99%, ClearlyFiltered 99%, Aquagear 77%, Brita Elite 20%; Brita Elite fell from 36% at 20 L to 8% at 160 L Limits: Canadian waters (Quebec); 4-5 brands; clogging prevented reaching 160 L in home test |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Endres K, ... George CM. Behavioral determinants of arsenic-safe water use among Great Plains Indian Nation private well users (Strong Heart Water Study). Environmental Health 22:42 (2023) · new peer-reviewed cluster RCT |
"51% (35/69) of participants lived in a household that reported changing their arsenic filter cartridge."; exclusive arsenic-safe water for drinking rose "from 12% (10/84) at baseline to 41% (31/75) at follow-up" Limits: Small (n=69), arsenic POU on private wells in tribal communities, trial setting with support; not generalisable to pitcher/fridge users; timing vs schedule not reported |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Choudhary K, Lanzarini-Lopes M, Parzen H, Perez Medina X, Reckhow D, Rogers R, Tobiason J, Wittbold P. PFAS Point-of-Use Treatment System Study: Final Report (UMass Amherst for MassDEP) (2023) · new government-funded field test report |
"Five of the 17 filters showed an effluent PFAS6 concentration below the Massachusetts MCL of 20 ng/L" (at 100% capacity); PUR faucet at 200% "increased above the MCL to 32 ng/L"; 200% tested "in recognition that some consumers may not perform required maintenance" Limits: One well, one water chemistry, two sampling points only; device count inconsistent (17 vs 20) |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Wu C-C, Love NG, Olson TM. Bacterial transmission and colonization in activated carbon block point-of-use filters. Environ. Sci.: Water Res. Technol. (2021) · new peer-reviewed lab study |
Spiked P. aeruginosa effluent plateaued at "two times the influent level"; filters clogged ~day 13 (~100 L) Limits: Lab spiking; ran only ~44% of rated volume |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Herkert NJ, Merrill J, Peters C, Bollinger D, Zhang S, Hoffman K, Ferguson PL, Knappe DRU, Stapleton HM. Assessing the Effectiveness of Point-of-Use Residential Drinking Water Filters for PFASs. Environ. Sci. Technol. Lett. 7:178-184 (2020) · new peer-reviewed field sampling |
"These filters ranged in age from <1 month to >5 years, with an average reported age of 7.5 months." (in-use filters, central NC) Limits: n=76 filters, one region, self-reported age; no statistical correlation of removal with age found |
Evidence: moderate Access unknown · source · added 2026-10-30 |
| City of Newark / Newark Lead Service Line programme: filter study announcement (2019) · new municipal field study summary |
"97.5% of the filters, when properly installed and maintained, reduced lead to 10 parts-per-billion (ppb) or below."; with 5-min flush "99.5%" Limits: Summary only; maintained filters only; full report not read |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Brown KW, Gessesse B, Butler LJ, MacIntosh DL. Potential Effectiveness of Point-of-Use Filtration to Address Risks to Drinking Water in the United States. Environ Health Insights 11 (2017) · new peer-reviewed review |
"faucet-mount or under-sink solid block activated carbon (SBAC) filters removed 80% to 99% of total Pb in 2 studies"; Flint: "no statistically significant difference between used and new filters" (n=161) Limits: Review co-authored by industry-funded consultants (check COI); Flint lead mostly soluble |
Evidence: moderate Free to read · source · added 2026-10-30 |
| NSF: NSF-Certified Drinking Water Filters Are Tested With Water Containing 150 ppb Lead (n.d.) · new standards-body summary |
test water "contains 150 parts per billion (ppb) of lead"; certified "to reduce lead to below 10 parts per billion (ppb)" Limits: Does not state % of capacity tested or pH; undated |
Evidence: moderate Free to read · source · added 2026-10-30 |
| Leaf Home (Pollfish) national tap-water sentiment survey, n=1,200 US adults, fielded 16 Jul 2025 (2025) · new industry-commissioned consumer survey |
"About 63% of respondents said they currently use a water filter at home."; pitcher 31%, refrigerator 27%, faucet-mounted 16%, whole-home 12%, under-sink 9% Limits: Commissioned by a filtration seller; no replacement data; multiple answers allowed; internal inconsistency on 2024 bottled-water figure |
Evidence: weak Free to read · source · added 2026-10-30 |
| Culligan national consumer survey, n=999 US adults, 7-9 Jun 2024 (press release) (2024) · new industry consumer survey |
"1 in 3 Americans rely on refrigerator filters for in-home water treatment" Limits: Manufacturer survey, no replacement data, no independent pollster named |
Evidence: weak Free to read · source · added 2026-10-30 |
| Gilliland A, Peluso V, Leyton-High C, Straif-Bourgeois S, Brisolara K, Pierce G, Pieper K, Katner A. Factors Impacting Adoption of and Experience with Point-of-Use Activated Carbon Faucet Mount Water Filters. J Louisiana Public Health Assoc 3(3) (2023) · new peer-reviewed mixed-methods (abstract only read) |
"There was some incorrect usage of POU filters by almost half the participants."; barrier: "lack of replacement parts in rural areas" Limits: Abstract only; small Louisiana sample; no replacement-timing figure |
Evidence: weak Free to read · source · added 2026-10-30 |
| Alfredo K, Wilson M, Roberson A. Management of point-of-use and point-of-entry for regulatory compliance: Survey of state administrators. AWWA Water Science e1335 (2023) · new peer-reviewed regulator survey |
"43 survey responses"; cartridge replacement frequency "is a great concern" (qualitative) Limits: No household behaviour data; state regulators, not consumers |
Evidence: weak Free to read · source · added 2026-10-30 |
| Water Quality Association. 2023 Consumer Opinion Study (Applied Research-West), n=1,412 US adults, Jan 2023, MoE +/-2.6% (2023) · new trade-association consumer survey |
"almost half (45%) of households have a water filtration system in the home"; "seven in 10 (71%) households purchasing bottled water" Limits: Industry body; public summary has no maintenance/replacement figures (full report may) |
Evidence: weak Free to read · source · added 2026-10-30 |
| City of Flint: Steps for Flint residents to reduce bacteria in filtered water (UM/Wayne State research) (2019) · new municipal guidance from university study |
flushing "can reduce the bacteria levels in water by 10 or 100 times"; replace after "about 100 gallons of water, or when the filter's red light goes on"; flush "15 seconds" Limits: Guidance page, not the paper |
Evidence: weak Free to read · source · added 2026-10-30 |
Evidence grade: strong = trials, large field studies or official datasets; moderate = smaller or lab studies with real water; weak = single small studies, makers' specs or secondary reports. "Free to read" means the source itself is free to read online.