States › New Hampshire › Merrimack County

Merrimack County, NH Water Quality

Water quality data for 23 public water systems serving Merrimack County, New Hampshire — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 23 water systems · 26 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

Merrimack County Earns a B

Merrimack County: 26 communities across 23 water systems. 100.0% have no open violations.

  • Median lead where detected: 22.00 ppb
  • 17 communities with a lead detection, 4 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 4 with significant inspection deficiencies
  • 100.0% of communities have no open violations
22 ppb
Median Lead Level
County-wide, 90th percentile
23
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
  • Concord
    1.00 ppb
    No federal limits exceeded on record
    A
  • Hooksett
    1.00 ppb
    No federal limits exceeded on record
    A
  • Bow
    Not reported
    No federal limits exceeded on record
    B
  • Webster
    Not reported
    No federal limits exceeded on record
    B
  • Canterbury
    Not reported
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Hill
    19.00 ppb
    Lead above the 15 ppb action level
    D
  • Hopkinton
    37.00 ppb
    Lead above the 15 ppb action level
    D
  • Andover
    56.00 ppb
    Lead above the 15 ppb action level
    D
  • Dunbarton
    16.00 ppb
    Lead above the 15 ppb action level
    C
  • Sutton
    30.00 ppb
    Lead above the 15 ppb action level
    C
County Lead Level — Median 22 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 22 ppb — 146.7% of the federal action level
Systems by Lead Level
Under 5 ppb
3
10 – 15 ppb
14
No Data
9

All Cities in Merrimack County

Concord 1.00 ppb A
Franklin 3.00 ppb B
Pembroke Not detected A
Suncook Not detected A
Hooksett 1.00 ppb A
Henniker 19.00 ppb C
Boscawen Not detected A
New London 30.00 ppb C
Pittsfield 70.00 ppb C
Allenstown Not detected A
Hopkinton 37.00 ppb D
Northfield 36.00 ppb C
Epsom 23.00 ppb C
Warner 16.00 ppb C
Andover 56.00 ppb D
Loudon Not reported B
Bow Not reported B
Hill 19.00 ppb D
Webster Not reported B
Chichester 16.00 ppb C
Newbury 22.00 ppb C
Canterbury Not reported B
Bradford 381.00 ppb C
Wilmot Not reported B
Sutton 30.00 ppb C
Dunbarton 16.00 ppb C
Showing 26 cities
No active violations Active violations

About Merrimack County Drinking Water

Merrimack County is served by 23 water systems covering 26 communities. No community here has an open violation on record.

Of the communities reporting lead results, 17 recorded a detection, with a median of 22.00 ppb — 147% of the federal action level. 4 reported none detected, which means below the laboratory limit rather than an absence of lead.

No community here has PFAS above the federal limit on record. State inspectors recorded significant deficiencies at 4 of them.

Frequently Asked Questions

Is Merrimack County tap water safe to drink?▼
No community in Merrimack County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Merrimack County?▼
Among communities with a detection the median is 22.00 ppb, 147% of the 15 ppb action level. 4 reported none detected and 5 reported no result.
How many water systems serve Merrimack County?▼
23 community water systems serve 26 communities here.
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