PFOA
1.8× the limitPerfluorooctanoic acid
7ng/L
Each block = 4.0 ng/L federal MCL (2024)
EPA UCMR 5 · sampled 2023Evidence
Portsmouth Water Works serves 33,000 people from surface water. 31 results are on record. Two PFAS, PFOA and PFOS, each had a sample above a 2024 EPA limit (not a violation: the limits are judged on a yearly average, due 2029); 3 more are detected with no federal limit, and everything else measured is within its reference or not detected.
Each bar is drawn in blocks of the 4.0 ng/L federal MCL (2024), so the length shows how far above it the result sits.
7ng/L
Each block = 4.0 ng/L federal MCL (2024)
5ng/L
Each block = 4.0 ng/L federal MCL (2024)
3,248service lines inventoried
From the utility's inventory reported to EPA (2026Q2); not every required line type is reported yet. Look up your address with the utility.
0health-based violations in the last 10 years
From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit.
No result is not a pass. Your utility's annual water quality report may list them, and a certified lab test covers your own tap.
A federal limit (an MCL or action level) is an enforceable legal cap; a health goal is often stricter. Meeting the limit is a compliance fact, not a health clearance, and PurityMap publishes no overall compliance verdict.
A tap test can confirm levels at your home before you choose treatment.
PFOA 7 ng/L in one EPA sample, above the 4 ng/L limit EPA set in 2024 (+7 more PFAS detected)
Understand water treatment technologies →
Understand:PFAS in Portsmouth
★ Best choice: Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200), certified for PFOA, PFOS and lead.
| Pick | Product | Certification | Price | Link |
|---|---|---|---|---|
| ★ Best choice | Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200) | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | $$ | Check price on Amazon |
| Also good | AquaTru Carafe Countertop Reverse-Osmosis Purifier (AT100) | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | $$$ | Check price on Amazon |
| Also good | AquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000) | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | $$$ | Check price on Amazon |
| Pick | Product | Certification | Price | Link |
|---|---|---|---|---|
| Also good | Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M) | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | $$ | Check price on Amazon |
| Also good | Aquasana Clean Water Machine Countertop Filter (AQ-CWM2) | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | $$ | Check price on Amazon |
| Also good | Patriot Pure Ultimate Water Filtration System | Certified for PFOA and PFOS (NSF/ANSI 53, NSF, IAPMO) | $$ | Check price on Amazon |
| Also good | Waterdrop G3P600 Tankless Reverse-Osmosis System | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | $$$ | Check price on Amazon |
| Also good | Waterdrop G3P800 Tankless Reverse-Osmosis System | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | $$$ | Check price on Amazon |
Also: lead picks →
PurityMap earns a commission from these links. "Best choice" and "Budget pick" go to certified products first; commission never decides them. As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.
Lead service lines
PORTSMOUTH WATER WORKS reported 140 galvanized service lines to replace in EPA’s inventory (2026Q2). Many utilities replace these lines for free or share the cost. Ask PORTSMOUTH WATER WORKS whether your home’s line is on its list before you pay anyone.
PORTSMOUTH WATER WORKS (PWS ID NH1951010) is a public water system serving 33,000 people in Portsmouth, New Hampshire.
PORTSMOUTH WATER WORKS is on record as drawing from surface water. The source shapes which contaminants matter most for this system.
PurityMap's record for PORTSMOUTH WATER WORKS holds 31 findings: 2 above a reference, 4 detected within the reference, 3 detected with no limit and 22 not detected, from 31 evidence records. Every finding links to its source; a substance that was never monitored is shown as pending, not as a pass.
PurityMap does not issue a safety verdict. It publishes PORTSMOUTH WATER WORKS's measured results against each contaminant's benchmark so you can read them in context. Safety depends on the specific finding, your plumbing, and how the water reaches your tap.
The latest published record for PORTSMOUTH WATER WORKS is dated 2026-10-15. Utilities report on regulatory cycles, so results reflect the monitoring period rather than a live reading.
No. It is assessed at the water-system level from PORTSMOUTH WATER WORKS's own monitoring. It does not cover the service line to your building or the plumbing inside it, which can add lead and other metals after the water leaves the system. A tap test is the way to know what reaches your glass.
Perfluorooctanoic acid (PFOA), Perfluorooctanesulfonic acid (PFOS), Lithium, Perfluorohexanesulfonic acid (PFHxS), Perfluorobutanesulfonic acid (PFBS), Perfluorohexanoic acid (PFHxA), Perfluorobutanoic acid (PFBA), Perfluoroheptanoic acid (PFHpA) and Perfluoropentanoic acid (PFPeA) were detected in this record. Each finding shows its measured value, its reference and its source on this page.
Start with what the record shows: the PFAS findings above list each measured value against its reference. This record cannot show your home's plumbing, so a tap test tells you what reaches your glass. If you decide to treat your water, look for a filter whose certification covers the specific PFAS compounds in your record; the section "Certified for a concern found here" lists only products with a current certification record for these concerns.
Follow Portsmouth Water Works
One email when a new sampling round is published, a result moves above or below its reference, or the system's score changes.
Follow this water →As listed for this system in EPA's records. Your water bill names your supplier.
| Substance | Result | Reference | Sampled | Status | Evidence |
|---|---|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | 2023-07-18 to 2024-05-10 | Not detected | — |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluorobutanoic acid (PFBA) | 5 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Detected, no limit | View evidence |
| Perfluorobutanesulfonic acid (PFBS) | 9 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit) | 2023-07-18 to 2024-05-10 | Below limit | View evidence |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluoroheptanoic acid (PFHpA) | 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Detected, no limit | View evidence |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluorohexanoic acid (PFHxA) | 6 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | 2023-07-18 to 2024-05-10 | Below limit | View evidence |
| Perfluorohexanesulfonic acid (PFHxS) | 5 ng/L | 10 ng/L federal MCL (2024) | 2023-07-18 to 2024-05-10 | Below limit | View evidence |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluorooctanoic acid (PFOA) | 7 ng/L | 4.0 ng/L federal MCL (2024) | 2023-07-18 to 2024-05-10 | Above guideline | View evidence |
| Perfluorooctanesulfonic acid (PFOS) | 5 ng/L | 4.0 ng/L federal MCL (2024) | 2023-07-18 to 2024-05-10 | Above guideline | View evidence |
| Perfluoropentanoic acid (PFPeA) | 7 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Detected, no limit | View evidence |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | 2023-07-18 to 2024-05-10 | Not detected | — |
| Lithium | 10 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit) | 2023-07-18 to 2024-05-10 | Below limit | View evidence |
| Lead (90th percentile) | Non-Detect (ND) | 15 µg/L federal action level | 2024–2024 monitoring period | Not detected | View evidence |
UCMR5 Analytical Results
UCMR5 Analytical Results: PORTSMOUTH WATER WORKS (NH1951010)
US EPA
State SDWIS Compliance Record
Lead & Copper Rule 90th-percentile: PORTSMOUTH WATER WORKS (NH1951010)
US EPA SDWIS