States › New Hampshire › Sullivan County

Sullivan County, NH Water Quality

Water quality data for 9 public water systems serving Sullivan County, New Hampshire — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 9 water systems · 9 cities
✅
Generally Safe — Most Systems Performing Well

The majority of water systems have no active violations and lead levels well below the federal action level.

B

Sullivan County Earns a B

Sullivan County: 9 communities across 9 water systems. 100.0% have no open violations.

  • Median lead where detected: 16.00 ppb
  • 7 communities with a lead detection, 1 reporting none detected
  • 1 communities with PFAS above the federal limit
  • 0 with significant inspection deficiencies
  • 100.0% of communities have no open violations
16 ppb
Median Lead Level
County-wide, 90th percentile
9
Water Systems
Active CWS & NTNCWS
100%
Violation-Free
No active violations on record
How we grade counties: MyWaterIQ uses EPA SDWIS enforcement data — actual MCL violations and lead test results — not the aspirational MCLG targets used by some sites. A grade reflects real compliance history, not theoretical risk. Learn more →

Cities by Water Quality

⭐ Best Performing
  • Unity
    Not reported
    No federal limits exceeded on record
    B
  • Claremont
    2.00 ppb
    1 health-based violation since 2015
    A
  • Newport
    14.00 ppb
    Lead at 14.00 ppb, above a third of the action level
    A
  • Grantham
    7.00 ppb
    Lead at 7.00 ppb, above a third of the action level
    A
  • Charlestown
    19.00 ppb
    Lead above the 15 ppb action level
    C
⚠ Needs Attention
  • Sunapee
    16.00 ppb
    Lead above the 15 ppb action level
    D
  • Plainfield
    28.00 ppb
    Lead above the 15 ppb action level
    C
  • Springfield
    30.00 ppb
    Lead above the 15 ppb action level
    C
  • Langdon
    Not detected
    PFAS above the limit at 1 of 8 sampling points
    C
  • Charlestown
    19.00 ppb
    Lead above the 15 ppb action level
    C
County Lead Level — Median 16 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 16 ppb — 106.7% of the federal action level
Systems by Lead Level
Under 5 ppb
1
5 – 10 ppb
1
10 – 15 ppb
5
No Data
2

All Cities in Sullivan County

Claremont 2.00 ppb A
Newport 14.00 ppb A
Charlestown 19.00 ppb C
Grantham 7.00 ppb A
Sunapee 16.00 ppb D
Plainfield 28.00 ppb C
Unity Not reported B
Springfield 30.00 ppb C
Langdon Not detected C
Showing 9 cities
No active violations Active violations

About Sullivan County Drinking Water

Sullivan County is served by 9 water systems covering 9 communities. No community here has an open violation on record.

Of the communities reporting lead results, 7 recorded a detection, with a median of 16.00 ppb — 107% of the federal action level. 1 reported none detected, which means below the laboratory limit rather than an absence of lead.

1 of 9 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded no significant deficiencies.

Frequently Asked Questions

Is Sullivan County tap water safe to drink?▼
No community in Sullivan County has an open violation on record. 1 of 9 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Sullivan County?▼
Among communities with a detection the median is 16.00 ppb, 107% of the 15 ppb action level. 1 reported none detected and 1 reported no result.
How many water systems serve Sullivan County?▼
9 community water systems serve 9 communities here.
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