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Updated 2026-09-16
State water report

New Hampshire Water Quality: 16 Cities Ranked by the Records

Water quality across 16 cities in New Hampshire, drawn from EPA drinking-water records. Each city page shows the measured contaminants and a reproducible Purity Score.

Finding by finding

What New Hampshire's records show

Counts of cities whose serving system reported each result. There is no statewide score: PurityMap does not average local records into a statewide safety verdict.

City rankings

New Hampshire cities ranked by the records

Highest first. A summary of each serving system’s record, not a safety verdict.

  1. 1
    NashuaPENNICHUCK WATER WORKS · NH1621010
    Report →
  2. 2
    Merrimack Village DistMERRIMACK VILLAGE DIST · NH1531010
    Report →
  3. 3
    SomersworthSOMERSWORTH WATER WORKS · NH2151010
    Report →
  4. 4
    ConcordCONCORD WATER DEPT · NH0501010
    Report →
  5. 5
    DoverDOVER WATER DEPT · NH0651010
    Report →
  6. 6
    LebanonLEBANON WATER DEPT · NH1321010
    Report →
  7. 7
    RochesterROCHESTER WATER DEPT · NH2001010
    Report →
  8. 8
    LaconiaLACONIA WATER WORKS · NH1281010
    Report →
  9. 9
    DerryDERRY WATER DEPT · NH0611010
    Report →
  10. 10
    KeeneKEENE WATER DEPT · NH1241010
    Report →

Showing the top 10 of 16 scored cities.

See all 16 in the table

16 cities, highest Purity Score first

  1. 1Nashua
    PENNICHUCK WATER WORKS · PWSID NH1621010 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  2. 2Merrimack Village Dist
    MERRIMACK VILLAGE DIST · PWSID NH1531010 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  3. 3Somersworth
    SOMERSWORTH WATER WORKS · PWSID NH2151010 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  4. 4Concord
    CONCORD WATER DEPT · PWSID NH0501010 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1 µg/LDetected
  5. 5Dover
    DOVER WATER DEPT · PWSID NH0651010 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1 µg/LDetected
  6. 6Lebanon
    LEBANON WATER DEPT · PWSID NH1321010 · Purity Score 97/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  7. 7Rochester
    ROCHESTER WATER DEPT · PWSID NH2001010 · Purity Score 96/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 2 µg/LDetected
  8. 8Laconia
    LACONIA WATER WORKS · PWSID NH1281010 · Purity Score 95/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 4 µg/LDetected
  9. 9Derry
    DERRY WATER DEPT · PWSID NH0611010 · Purity Score 76/100 (Good) · Confidence: moderate · Assessed at the water-system level
    PFOA 4.6 ng/L, 1.1× the EPA limitAbove reference
  10. 10Keene
    KEENE WATER DEPT · PWSID NH1241010 · Purity Score 75/100 (Good) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  11. 11Manchester
    MANCHESTER WATER WORKS · PWSID NH1471010 · Purity Score 73/100 (Fair) · Confidence: moderate · Assessed at the water-system level
    PFOA 5 ng/L, 1.3× the EPA limitAbove reference
  12. 12Portsmouth
    PORTSMOUTH WATER WORKS · PWSID NH1951010 · Purity Score 63/100 (Fair) · Confidence: moderate · Assessed at the water-system level
    PFOA 7 ng/L, 1.8× the EPA limit (+1 more PFAS above)Above reference
Showing 12 of 16.

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no state score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works. See how New Hampshire compares with other states.

By contaminant

PFAS and lead in New Hampshire

Counties

New Hampshire counties

7 counties with city reports
Suppliers

Largest water systems

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Full indexAll 16 New Hampshire city reports, A–Z
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Questions

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How does New Hampshire tap water compare across cities?

PurityMap ranks 16 cities in New Hampshire by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Nashua's main water system: PENNICHUCK WATER WORKS · PWSID NH1621010 · Purity Score 100 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many New Hampshire cities have PFAS above the federal limit?

7 cities of 16 had at least one regulated PFAS (PFOA, PFOS or PFHxS) measured above the 2024 federal limit in EPA's UCMR 5 testing, including Hudson (PFOA 9 ng/L), Salem (PFOA 8.5 ng/L), Seabrook (PFOA 8 ng/L). PFAS were detected at any level in 7.

Is there lead in New Hampshire tap water?

Utilities report lead as a 90th-percentile result from home taps. 6 of 16 New Hampshire cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Limits, sources and corrections

A statewide page cannot tell you what reaches a specific address. Water quality varies by supplier, sampling period and household plumbing; open a city report for the evidence behind a local result.

Sources: EPA UCMR 5 (PFAS, 2024), SDWIS Lead and Copper Rule 90th-percentile results and health-based violations, and utility Consumer Confidence Reports where on file. Every city report links its dated source records.

Updated 2026-09-16. How PurityMap analyzes water data · Report an error