States › Massachusetts › Barnstable County

Barnstable County, MA Water Quality

Water quality data for 14 public water systems serving Barnstable County, Massachusetts — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 14 water systems · 15 cities
✅
Excellent — All Systems Performing Well

Water quality across the county is outstanding with minimal violations and very low lead levels.

A

Barnstable County Earns a A

Barnstable County: 15 communities across 14 water systems. 100.0% have no open violations.

  • Median lead where detected: 2.00 ppb
  • 10 communities with a lead detection, 5 reporting none detected
  • 1 communities with PFAS above the federal limit
  • 0 with significant inspection deficiencies
  • 100.0% of communities have no open violations
2 ppb
Median Lead Level
County-wide, 90th percentile
14
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
  • Sandwich
    Not detected
    No federal limits exceeded on record
    A
  • Dennis
    Not detected
    No federal limits exceeded on record
    A
  • Mashpee
    1.40 ppb
    No federal limits exceeded on record
    A
  • Harwich
    Not detected
    No federal limits exceeded on record
    A
  • Brewster
    3.40 ppb
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Barnstable Town
    2.40 ppb
    PFAS above the limit at 1 of 15 sampling points
    B
  • Wellfleet
    3.00 ppb
    Copper above the 1,300 ppb action level
    B
  • Falmouth
    1.10 ppb
    5 health-based violations since 2015
    B
  • Chatham
    1.10 ppb
    3 health-based violations since 2015
    B
  • Bourne
    4.40 ppb
    Copper above the 1,300 ppb action level
    A
County Lead Level — Median 2 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2 ppb — 13.3% of the federal action level
Systems by Lead Level
Under 5 ppb
10
No Data
5

All Cities in Barnstable County

Falmouth 1.10 ppb B
Yarmouth 1.50 ppb A
Barnstable Town 2.40 ppb B
Sandwich Not detected A
Dennis Not detected A
Mashpee 1.40 ppb A
Harwich Not detected A
Brewster 3.40 ppb A
Bourne 4.40 ppb A
Chatham 1.10 ppb B
Orleans Not detected A
Eastham Not detected A
Provincetown 2.00 ppb A
Wellfleet 3.00 ppb B
Truro 2.00 ppb A
Showing 15 cities
No active violations Active violations

About Barnstable County Drinking Water

Barnstable County is served by 14 water systems covering 15 communities. No community here has an open violation on record.

Of the communities reporting lead results, 10 recorded a detection, with a median of 2.00 ppb — 13% of the federal action level. 5 reported none detected, which means below the laboratory limit rather than an absence of lead.

1 of 15 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 Barnstable County tap water safe to drink?▼
No community in Barnstable County has an open violation on record. 1 of 15 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Barnstable County?▼
Among communities with a detection the median is 2.00 ppb, 13% of the 15 ppb action level. 5 reported none detected and 0 reported no result.
How many water systems serve Barnstable County?▼
14 community water systems serve 15 communities here.
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