City water report · 2026

Is Portsmouth, NH Tap Water Safe to Drink?

Short answer: In the 2023–2024 records we hold for Portsmouth, 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. 9 substances were detected and 22 were tested and not detected. The water is from Portsmouth Water Works, serving 33,000 residents.

  • Year 2026
  • Utility Portsmouth Water Works
  • Coverage 31 records
  • Updated 2026-10-15
Water utility

Where Portsmouth’s water comes from

Utility
Portsmouth Water Works
Water system
PORTSMOUTH WATER WORKS · NH1951010
Source water
Surface water
Disinfectant
not on record
Population served
33,000
Reporting period
Sampled 2023–2024
Monitoring coverage
31 records · 3 of 4 groups measured
Service lines
0 lead, 140 galvanized, 3,108 unknown material (EPA inventory, 2026Q2)
Likely match, check your bill

2 water systems report serving Portsmouth. This report uses the largest, PORTSMOUTH WATER WORKS. Your water bill names your actual supplier. Source: EPA SDWIS 2026Q2.

Why this matters
  1. 1
    Source

    Surface water

  2. 2
    Treatment

    The treatment details are not on record.

  3. 3
    Distribution

    Mains, then your building’s service line.

  4. 4
    Your tap

    Plumbing inside the building is outside this record.

At a glance

Portsmouth water in four numbers

Purity ScorePORTSMOUTH WATER WORKS · PWSID NH1951010
9Detected2 with a sample above a 2024 EPA limit
2With a sample above a 2024 EPA limitof 31 records
0Health-based violationslast 10 years · EPA SDWIS

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.

What we found

9 detected results, by distance from their limit

Perfluorooctanoic acid (PFOA)Above EPA's 2024 limit (one sample) · Federal MCL4.0 ng/L federal MCL (2024)7ng/L
① · Measured

7 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

4.0 ng/L federal MCL (2024): a legal limit. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. EPA health goal (MCLG): 0.

③ · Meaning

One EPA sample measured 7 ng/L, above the 4 ng/L limit EPA set in 2024. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation.

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58 (PFOA/PFOS)).

See the evidence record →
Perfluorooctanesulfonic acid (PFOS)Above EPA's 2024 limit (one sample) · Federal MCL4.0 ng/L federal MCL (2024)5ng/L
① · Measured

5 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

4.0 ng/L federal MCL (2024): a legal limit. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. EPA health goal (MCLG): 0.

③ · Meaning

One EPA sample measured 5 ng/L, above the 4 ng/L limit EPA set in 2024. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation.

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58 (PFOA/PFOS)).

See the evidence record →
LithiumWithin reference · Screening level10 µg/L EPA health reference level (screening, not a legal limit)10µg/L
① · Measured

10 µg/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

10 µg/L EPA health reference level (screening, not a legal limit).

③ · Meaning

Detected at up to 10 µg/L (below the 10 µg/L EPA health reference level; a screening level, not a legal limit).

④ · Where it matters

Where it enters is not in this record.

⑤ · What to do

Test your own tap first: a certified lab result shows what reaches your glass.

See the evidence record →
Perfluorohexanesulfonic acid (PFHxS)Within reference · Federal MCL10 ng/L federal MCL (2024)5ng/L
① · Measured

5 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

10 ng/L federal MCL (2024): a legal limit. That limit is judged on a yearly average, and water systems have until 2029 to meet it.

③ · Meaning

Detected at up to 5 ng/L (below the 10 ng/L limit EPA set in 2024). That limit is judged on a yearly average, and water systems have until 2029 to meet it.

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFHxS named on the listing).

See the evidence record →
Perfluorobutanesulfonic acid (PFBS)Within reference · Screening level2,000 ng/L EPA health advisory (screening, not a legal limit)9ng/L
① · Measured

9 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

2,000 ng/L EPA health advisory (screening, not a legal limit).

③ · Meaning

Detected at up to 9.0 ng/L (below the 2,000 ng/L EPA health advisory; a screening level, not a legal limit).

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFBS named on the listing).

See the evidence record →
Perfluorohexanoic acid (PFHxA)Within reference · State limit400,000 ng/L Michigan EGLE state MCL (strictest US state)6ng/L
① · Measured

6 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

400,000 ng/L Michigan EGLE state MCL (strictest US state): a state limit.

③ · Meaning

Detected at up to 6.0 ng/L (below the 400,000 ng/L historical comparison reference).

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFHxA named on the listing).

See the evidence record →
Perfluorobutanoic acid (PFBA)Detected · no limit · No federal limitNo federal or state limit; shown for transparency5ng/L
① · Measured

5 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

No federal limit is on record for it.

③ · Meaning

Detected at up to 5.0 ng/L. No federal or state limit exists for this substance; shown for transparency, not graded.

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFBA named on the listing).

See the evidence record →
Perfluoroheptanoic acid (PFHpA)Detected · no limit · No federal limitNo federal or state limit; shown for transparency3ng/L
① · Measured

3 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

No federal limit is on record for it.

③ · Meaning

Detected at up to 3.0 ng/L. No federal or state limit exists for this substance; shown for transparency, not graded.

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFHpA named on the listing).

See the evidence record →
Perfluoropentanoic acid (PFPeA)Detected · no limit · No federal limitNo federal or state limit; shown for transparency7ng/L
① · Measured

7 ng/L, sampled 2023-07-18 to 2024-05-10. EPA UCMR 5.

② · Compared

No federal limit is on record for it.

③ · Meaning

Detected at up to 7.0 ng/L. No federal or state limit exists for this substance; shown for transparency, not graded.

④ · Where it matters

Comes with the source water; home plumbing does not add it.

⑤ · What to do

Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFPeA named on the listing).

See the evidence record →
22 others tested, none detectedshow
  • 11Cl-PF3OUdS
  • 8:2 FTS
  • 4:2 FTS
  • 6:2 FTS
  • ADONA
  • 9Cl-PF3ONS
  • HFPO-DA (GenX)
  • Lead (90th percentile)
  • NEtFOSAA
  • NMeFOSAA
  • NFDHA
  • PFEESA
  • PFMPA
  • PFMBA
  • PFDA
  • PFDoA
  • PFHpS
  • PFNA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

PORTSMOUTH WATER WORKS (EPA PWSID NH1951010) delivers surface water to 33,000 residents. This report reflects 29 individual PFAS result(s) from the source UCMR5 observations and the latest Lead & Copper Rule 90th-percentile result. Water hardness and disinfectant type are pending the utility's own annual report.

Track record

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.

Not in this recordDisinfection by-products weren't monitored in this dataset

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.

Your household

Your tap can differ from the city record

The record describes water leaving treatment and samples across the system. Pipes, solder and fixtures inside a building can add lead the record can’t see, especially in older buildings with lead service lines.

Test your water
  1. City
    Treated water

    Measured in this report

  2. Mains
    Distribution network

    Sampled across the system

  3. Building
    Service line and plumbing

    Not in this record

  4. Tap
    Your glass

    Only a tap test measures it

Test first, then treat

Water testing in Portsmouth, NH

  1. 01Test

    Know what comes from your tap, starting with a first-draw lead sample.

  2. 02Match

    Compare each result with its named reference in our test reader.

  3. 03Treat

    Choose a technology certified for what your test found.

Commercial

Test kits

Affiliate links

Screening tells you if something is worth a closer look; a lab result is the number you can act on.

As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.

  • Lab-certified results

    ETR Labs Basic Water Quality Test Kit

    ETR Laboratories

    50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria

    What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.

  • Screening: quick check, not lab-grade

    Safe Home DIY Lead in Drinking Water Combo Test Kit

    Safe Home (EnviroTestKits)

    Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb

    • Turnaround: 5 minutes

    What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.

When your results arrive, read them here → · Compare every kit we list

New Hampshire Department of Environmental Services certifies the labs that test drinking water in New Hampshire. Find a certified lab in New Hampshire ↗ · What lab tests cost →

Treatment matching

What can reduce what was found here

FindingReference typeTechnologyCertification to check
Perfluorooctanoic acid (PFOA)7 ng/LFederal MCLReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58 (PFOA/PFOS)
Perfluorooctanesulfonic acid (PFOS)5 ng/LFederal MCLReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58 (PFOA/PFOS)
Perfluorohexanesulfonic acid (PFHxS)5 ng/LFederal MCLReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58, with PFHxS named on the listing
Perfluorobutanesulfonic acid (PFBS)9 ng/LScreening levelReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58, with PFBS named on the listing
Perfluorohexanoic acid (PFHxA)6 ng/LState limitReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58, with PFHxA named on the listing
Perfluorobutanoic acid (PFBA)5 ng/LNo federal limitReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58, with PFBA named on the listing
Perfluoroheptanoic acid (PFHpA)3 ng/LNo federal limitReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58, with PFHpA named on the listing
Perfluoropentanoic acid (PFPeA)7 ng/LNo federal limitReverse osmosis, or carbon certified for PFASNSF/ANSI 53 or 58, with PFPeA named on the listing
Galvanized service lines140 galvanized on record (EPA inventory, 2026Q2)Not a tap measurementLead-certified carbon filter, or reverse osmosisNSF/ANSI 53 (lead)

Understand water treatment technologies →

Commercial

Filters for the PFAS found in Portsmouth water

Affiliate links

★ Best choice: Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200), certified for PFOA, PFOS and lead.

Filters for the PFAS found in Portsmouth water
PickProductDetails and priceCertificationWhy it’s listedLink
★ Best choiceUnder-sinkAquasana Claryum 2-Stage Under-Sink Filter (AQ-5200)AquasanaTreatsPFOA, PFOS and leadPrice$$Certified for PFOA and PFOS (NSF/ANSI 53, WQA)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck price on Amazon
Also goodCountertopAquaTru Carafe Countertop Reverse-Osmosis Purifier (AT100)AquaTruTreatsPFOA, PFOS and leadPrice$$$Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck price on Amazon
Also goodCountertopAquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000)AquaTruTreatsPFOA, PFOS and leadPrice$$$Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck price on Amazon
See all 8 drinking-water options for PFAS
More drinking-water options for PFAS
PickProductDetails and priceCertificationWhy it’s listedLink
Also goodUnder-sinkAquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M)AquasanaTreatsPFOA, PFOS and leadPrice$$Certified for PFOA and PFOS (NSF/ANSI 53, WQA)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck price on Amazon
Also goodCountertopAquasana Clean Water Machine Countertop Filter (AQ-CWM2)AquasanaTreatsPFOA, PFOS and leadPrice$$Certified for PFOA and PFOS (NSF/ANSI 53, WQA)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck price on Amazon
Also goodCountertopPatriot Pure Ultimate Water Filtration SystemPatriot Pure (4Patriots)TreatsPFOA, PFOS and leadPrice$$Certified for PFOA and PFOS (NSF/ANSI 53, NSF, IAPMO)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck price on Amazon
Also goodUnder-sinkWaterdrop G3P600 Tankless Reverse-Osmosis SystemWaterdropTreatsPFOA, PFOS and leadPrice$$$Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck price on Amazon
Also goodUnder-sinkWaterdrop G3P800 Tankless Reverse-Osmosis SystemWaterdropTreatsPFOA, PFOS and leadPrice$$$Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO)Why it’s listed: its current certification names PFOA and PFOS, found in Portsmouth’s record.See the evidenceCheck 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

Ask your utility first

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.

Is this right for my home?

Choose your situation

Your situation
Your path: I live in an older buildingLead from plumbing is the main question

Older buildings may have lead service lines, solder or fixtures. Portsmouth’s utility reported 140 galvanized service lines in EPA’s inventory. Test first-draw water, then filter if needed.

Look forLead reduction: NSF/ANSI 53 (lead)
How to test your tap →
Your path: I care about PFASCheck what was tested

8 of 29 PFAS tested were detected in Portsmouth’s record (PFOA 7 ng/L, PFOS 5 ng/L and PFHxS 5 ng/L, and more); 2 above their limit. If PFAS matters to you, a filter certification names each compound it covers.

Look forNSF/ANSI 53 or 58, with each compound you care about named on the listing
PFAS in Portsmouth →
Your path: My water tastes of chlorineThe disinfectant is not in this record

Most utilities keep chlorine or chloramine in the pipes. A carbon filter certified for taste and odor reduces either; your utility can tell you which it uses.

Look forNSF/ANSI 42 (chlorine taste and odor)
Water treatment technologies →
Your path: I have scale or hard waterHardness is not in this record

Your utility’s annual water quality report usually lists hardness; a test strip also measures it.

Look forSoftener: NSF/ANSI 44 (softeners)
Hard water explained →
Your path: I want the broadest reductionReverse osmosis at one tap

Reverse osmosis reduces many dissolved contaminants, including lead and minerals, at a single faucet, with some water sent to drain.

Look forNSF/ANSI 58
Compare treatments →
Questions

Portsmouth tap water FAQ

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Is Portsmouth tap water safe to drink?

PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For Portsmouth, PFOA 7 ng/L and PFOS 5 ng/L were measured in one EPA sample each, above the 4 ng/L limit EPA set in 2024 (not a violation: the limits are judged on a yearly average, due 2029). PORTSMOUTH WATER WORKS (PWSID NH1951010) has a Purity Score of 63/100 (confidence: moderate), assessed at the water-system level and computed only from contaminants that were measured. Water can change in your own pipes, so a certified test is the only way to know what comes out of your tap. What we found →

Who provides tap water in Portsmouth?

PORTSMOUTH WATER WORKS (PWS ID NH1951010) is the public water system on record for Portsmouth, New Hampshire, serving about 33,000 people. Confirm the utility on your water bill before acting on a specific finding. Water utility →

Where does Portsmouth get its drinking water?

Surface water (primary source of record in EPA SDWIS). Water utility →

Are PFAS "forever chemicals" in Portsmouth's water?

Yes. In EPA's UCMR 5 testing (2023-07-18 to 2024-05-10), PFOA was measured at 7 ng/L in one EPA sample, above the 4 ng/L limit EPA set in 2024 and PFOS was measured at 5 ng/L in one EPA sample, above the 4 ng/L limit EPA set in 2024. EPA's 2024 limits are judged on a yearly average, and water systems have until 2029 to meet them, so a single sample is not a violation. PFBS (9 ng/L, below the 2,000 ng/L EPA health advisory), PFHxA (6 ng/L, below the 400,000 ng/L state limit) and PFHxS (5 ng/L, below the 10 ng/L federal limit) were also detected. PFBA (5 ng/L), PFHpA (3 ng/L) and PFPeA (7 ng/L) were also detected; they have no federal or state limit. Reverse osmosis and filters certified to NSF/ANSI 53 for PFOA/PFOS reduce them at the tap. What we found →

Is there lead in Portsmouth's tap water?

Lead is not in Portsmouth's current published record. Lead usually enters from a building's own pipes and fixtures, so a certified home test is the way to know yours. Your household →

What does the latest Portsmouth water report show?

PurityMap's current record for Portsmouth holds 31 findings: 2 above a reference, 4 detected within the reference, 3 detected with no limit and 22 not detected. Each finding links to its dated public record; a parameter that was never monitored is shown as pending, not as a pass. Records →

Data and sources

31 records, each traceable

  • EPA UCMR 5
  • EPA SDWIS (Lead & Copper Rule)
ContaminantMeasuredReferenceSampledSource
Perfluorooctanoic acid (PFOA)7 ng/L4.0 ng/L federal MCL (2024)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorooctanesulfonic acid (PFOS)5 ng/L4.0 ng/L federal MCL (2024)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Lithium10 µg/L10 µg/L EPA health reference level (screening, not a legal limit)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorohexanesulfonic acid (PFHxS)5 ng/L10 ng/L federal MCL (2024)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorobutanesulfonic acid (PFBS)9 ng/L2,000 ng/L EPA health advisory (screening, not a legal limit)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorohexanoic acid (PFHxA)6 ng/L400,000 ng/L Michigan EGLE state MCL (strictest US state)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorobutanoic acid (PFBA)5 ng/LNo federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoroheptanoic acid (PFHpA)3 ng/LNo federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoropentanoic acid (PFPeA)7 ng/LNo federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)< 5 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)< 5 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)< 3 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)< 5 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)< 3 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)< 2 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)< 5 ng/L (not detected)10 ng/L federal MCL (2024)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Lead (90th percentile)Not detected15 µg/L federal action level2024EPA SDWIS (Lead & Copper Rule) ↗ (opens in a new tab)
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)< 5 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)< 6 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)< 20 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)< 3 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoro-3-methoxypropanoic acid (PFMPA)< 4 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoro-4-methoxybutanoic acid (PFMBA)< 3 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorodecanoic acid (PFDA)< 3 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorododecanoic acid (PFDoA)< 3 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoroheptanesulfonic acid (PFHpS)< 3 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorononanoic acid (PFNA)< 4 ng/L (not detected)10 ng/L federal MCL (2024)2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoropentanesulfonic acid (PFPeS)< 4 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorotetradecanoic acid (PFTA)< 8 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluorotridecanoic acid (PFTrDA)< 7 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
Perfluoroundecanoic acid (PFUnA)< 2 ng/L (not detected)No federal or state limit; shown for transparency2023–2024EPA UCMR 5 ↗ (opens in a new tab)
  • UCMR5 Analytical Results

    UCMR5 Analytical Results: PORTSMOUTH WATER WORKS (NH1951010)

    US EPA

    Published
    2026-10-15
    Newest sample
    2024-05-10
    Findings here
    30
  • State SDWIS Compliance Record

    Lead & Copper Rule 90th-percentile: PORTSMOUTH WATER WORKS (NH1951010)

    US EPA SDWIS

    Published
    2026-10-13
    Newest sample
    2024
    Findings here
    1

Methodology: how we analyze water. Prepared with AI assistance and reviewed by the PurityMap Editorial Team before publication.

Methodology

How PurityMap reads Portsmouth’s water

  1. 01Source data

    EPA SDWIS, EPA UCMR 5 and utility reports, each dated and linked.

  2. 02Normalize

    Units converted to one basis; a non-detect kept distinct from zero.

  3. 03Classify

    Each result tagged by reference type: MCL, action level, screening level or aesthetic.

  4. 04Compare to the named reference

    Every value sits against its own reference, never a blended one.

  5. 05Score

    Measured subjects summarised at the water-system level; an open health-based violation caps the score.

  6. 06Match treatment

    Treatment is matched to what was found; a product is called certified only when its current certification names it.

What the Purity Score means: a summary of this water system’s published record, capped while a health-based violation is open. It is not a test of any tap. PORTSMOUTH WATER WORKS · PWSID NH1951010 · Purity Score 63/100 (Fair) · Confidence: moderate · Assessed at the water-system level

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