States › Massachusetts › Middlesex County

Middlesex County, MA Water Quality

Water quality data for 52 public water systems serving Middlesex County, Massachusetts — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 52 water systems · 54 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

Middlesex County Earns a B

Middlesex County: 54 communities across 52 water systems. 100.0% have no open violations.

  • Median lead where detected: 2.40 ppb
  • 48 communities with a lead detection, 6 reporting none detected
  • 13 communities with PFAS above the federal limit
  • 7 with significant inspection deficiencies
  • 100.0% of communities have no open violations
2.4 ppb
Median Lead Level
County-wide, 90th percentile
52
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
  • Ashby
    1.60 ppb
    No federal limits exceeded on record
    A
  • Framingham
    1.60 ppb
    No federal limits exceeded on record
    A
  • Waltham
    1.92 ppb
    No federal limits exceeded on record
    A
  • Arlington
    2.79 ppb
    No federal limits exceeded on record
    A
  • Marlborough
    3.30 ppb
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Maynard
    2.40 ppb
    PFAS above the limit at 1 of 3 sampling points
    D
  • Holliston
    2.90 ppb
    PFAS above the limit at 2 of 3 sampling points
    D
  • Acton
    3.60 ppb
    PFAS above the limit at 3 of 3 sampling points
    D
  • Hopkinton
    7.40 ppb
    PFAS above the limit at 1 of 3 sampling points
    C
  • Sudbury
    3.50 ppb
    PFAS above the limit at 3 of 5 sampling points
    C
County Lead Level — Median 2.4 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.4 ppb — 16% of the federal action level
Systems by Lead Level
Under 5 ppb
40
5 – 10 ppb
7
10 – 15 ppb
1
No Data
6

All Cities in Middlesex County

Cambridge 8.00 ppb A
Lowell Not detected A
Somerville 3.92 ppb B
Newton 1.28 ppb A
Framingham 1.60 ppb A
Malden 9.74 ppb B
Medford 8.35 ppb B
Waltham 1.92 ppb A
Everett 5.67 ppb A
Arlington 2.79 ppb A
Marlborough 3.30 ppb A
Woburn 1.28 ppb B
Billerica 2.40 ppb B
Natick Not detected C
Lexington 1.79 ppb A
Tewksbury 1.00 ppb A
Melrose 10.20 ppb C
Belmont 1.50 ppb A
Wakefield 1.54 ppb A
Chelmsford 2.40 ppb B
Burlington 2.20 ppb A
Reading 8.39 ppb B
Dracut Not detected B
Wilmington 1.80 ppb A
Stoneham 1.44 ppb B
Winchester 4.20 ppb A
Acton 3.60 ppb D
Westford 2.90 ppb A
Hudson 2.70 ppb A
Ashland 1.60 ppb A
Sudbury 3.50 ppb C
Concord 5.10 ppb C
North Reading 1.70 ppb C
Holliston 2.90 ppb D
Hopkinton 7.40 ppb C
Bedford 4.00 ppb A
Wayland 4.20 ppb C
Weston 2.03 ppb A
Pepperell 1.10 ppb C
Maynard 2.40 ppb D
Littleton Not detected A
Ayer 2.80 ppb A
Townsend 1.60 ppb A
Groton 4.70 ppb A
Lincoln 2.20 ppb C
Shirley 2.10 ppb A
Tyngsborough 1.50 ppb A
Hanscom AFB 1.50 ppb B
Dunstable 1.70 ppb B
Boxborough Not detected B
Stow 2.90 ppb B
Carlisle Not detected B
Sherborn 1.60 ppb A
Ashby 1.60 ppb A
Showing 54 cities
No active violations Active violations

About Middlesex County Drinking Water

Middlesex County is served by 52 water systems covering 54 communities. No community here has an open violation on record.

Of the communities reporting lead results, 48 recorded a detection, with a median of 2.40 ppb — 16% of the federal action level. 6 reported none detected, which means below the laboratory limit rather than an absence of lead.

13 of 54 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded significant deficiencies at 7 of them.

Frequently Asked Questions

Is Middlesex County tap water safe to drink?▼
No community in Middlesex County has an open violation on record. 13 of 54 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Middlesex County?▼
Among communities with a detection the median is 2.40 ppb, 16% of the 15 ppb action level. 6 reported none detected and 0 reported no result.
How many water systems serve Middlesex County?▼
52 community water systems serve 54 communities here.
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