Your water quality report, rewritten.
Your utility has to send you a water quality report every year, and most go straight into the recycling. Enter your ZIP code to see what EPA’s own records show is in your tap water, how each result compares with the legal limit and the health goal, and which certified filter handles it.
On a private well? No utility reports on your water, so the first step is a test. How to test well water
Philadelphia Water Department
PWSID PA1510001 · Serves 1.6 million people · Philadelphia, PA · Surface water
PFOA (above the health goal)
Comes from the source
8.1 (above the legal limit in at least one sample)ppt
Highest of 12 samples; found in eight
Above the 4.0 ppt legal limit in at least one sample. Compliance is judged on a running annual average, not one sample.
EPA UCMR 5, samples taken from Jan. 8, 2024 to Oct. 7, 2024. Each blue tick is one sample where it was found.
What handles it
- NSF/ANSI 53 with the claim “PFOA Reduction”
- NSF/ANSI 58 with the claim “Perfluorooctanoic Acid (PFOA)”
NSF’s PFAS claims are tested to below 20 ppt. EPA’s limit is 4.0 ppt, and EPA says no certification yet shows a filter reaching its levels.
Every result, on two yardsticks.
A utility report prints one number per contaminant and a column of acronyms. TapBuff measures each result against both lines EPA sets, and marks the ones worth your attention.
- Health goal
- The level below which EPA expects no risk to health, with a margin of safety. Not enforceable. EPA calls it the MCLG. For PFOA, PFOS and lead it is zero.
- Legal limit
- The most a utility may deliver, set as close to the goal as treatment and cost allow. Enforceable. EPA calls it the MCL. For lead and copper there is an action level instead.
- Highlighted
- Above the health goal in at least one result, or above EPA’s health benchmark where there is no goal. Worth reading about, not a reason to panic.
- Circled
- Above the legal limit in at least one sample, or above the action level for lead and copper. Compliance is judged over time, so this is not by itself a violation.
Where it gets in decides what fixes it.
Water picks things up at three points between the source and your glass. A report row tells you what; this tells you where, which decides the kind of filter that can help.
At the source
Rivers, lakes and aquifers carry these into the treatment plant. Whether they reach you depends on what the plant removes.
- PFOA
- PFOS
- PFHxS
- PFNA
- HFPO-DA (GenX)
- PFBS
- Lithium
- Nitrate
- Arsenic
- Uranium
- Chromium (total)
- Manganese
- Hardness
- Iron
- Hydrogen sulfide
What helps: A filter certified for the specific contaminant, at the tap or for the whole house. Whole-house options.
In treatment
Chlorine or chloramine keeps water safe on its way to you. Byproducts form when the disinfectant meets organic matter.
What helps: Carbon handles taste and odor. Byproducts need a health-effects claim, not just a taste claim. Whole-house options.
In your pipes
Lead and copper usually come from service lines, solder and fixtures. The utility’s plant never sees them.
What helps: Only a filter at the tap catches what your own plumbing adds after a whole-house unit.
What EPA found when it tested 9,949 utilities.
EPA’s fifth Unregulated Contaminant Monitoring Rule, UCMR 5, tested nearly every utility serving more than 3,300 people for 29 PFAS and lithium. PFAS turned up in 3,506 of them, which report serving 153 million people. At 1,667, at least one sample of PFOA or PFOS was above the new 4.0 ppt legal limit.
The national results, contaminant by contaminantThe number on the box, decoded.
A filter certified to a standard is only certified for the specific claims on its listing. Two filters can both say “NSF/ANSI 53” and remove different things.
- 42Taste, odor and appearance
- 53Health-related contaminants
- 58Reverse osmosis systems
- 401Emerging contaminants
- P473Retired PFOA/PFOS protocol
Often misread
Many sites say a filter certified to NSF/ANSI 42 removes lead. It does not. Every 42 claim is aesthetic, and lead reduction is a separate health claim under NSF/ANSI 53 or 58.
Count the whole cost.
The price on the box is the down payment. Cartridges are the rest, and they decide which filter is cheap.
Five-year statement
Household of 3 · 3 gal a day · 5,479 gal total
| Type | Lowest five-year cost | Total | Per gallon |
|---|---|---|---|
| Pitcher | Brita Tahoe Pitcher with Elite Filter (OB60, OB06)$42 up front, $900 in cartridges | $942 | 17¢ |
| Faucet mount | Brita Elite Water Filter Faucet System (SAFF-100/FF-100)$32 up front, $971 in cartridges | $1,004 | 18¢ |
| Under-sink carbon | Aquasana Claryum Direct Connect (AQ-MF-1)$250 up front, $828 in cartridges | $1,078 | 20¢ |
| Under-sink reverse osmosis | APEC Essence ROES-50$231 up front, $335 in cartridges | $566 | 10¢ |
| Countertop reverse osmosis | AquaTru Classic (AT2000)$475 up front, $869 in cartridges | $1,344 | 25¢ |
The costliest of these in the catalog is the ZeroWater 10 Cup Pitcher (ZP-010), at $7,334: 365 filters, 15 gallons each, replaced every 5 days.
Makers’ own list prices, checked Oct. 4, 2026. Cartridges replaced at the maker’s gallon or month rating, whichever comes first, at 1 gallon of drinking and cooking water per person per day.
Open your own report.
35,489 ZIP codes, matched to the utilities that serve them.