Barnstable County, Massachusetts
54 ZIP codes · Avg score 64/100 · Grade C · Updated 2026-06-03
Water safety in Barnstable County is uneven — some of its 54 ZIP codes meet standards cleanly while others carry documented violations.
How Barnstable County Compares
How Barnstable County Compares
Barnstable County scores 2 points below the Massachusetts state average (66/100) and 4 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Barnstable County, Massachusetts
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.9 (asthma 11.5%, diabetes 10.7%)
Estimated additional annual cost per homeowner: $2,642, driven primarily by flood
Infrastructure: 0.421% avg pipe failure probability, 54% of ZIPs at high risk
72.3% of homes built before 1978 (lead paint era)
Violation History (2021–2024)
→ Stable trendEPA violation counts by year across Barnstable County water systems. Health-based shown in red, total in blue.
Peak year: 2021 with 2 violations. Past 5 years: 4 total (4 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $2,642
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
159,259 housing units in Barnstable County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Barnstable County
Remediation costs are relatively manageable for most homeowners in Barnstable County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Barnstable County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Barnstable County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Wellfleet Municipal Water System | 750 | 10 |
| 2 | Massasoit Hills Trailer Park | 120 | 10 |
| 3 | PLEASANT WATER | 200 | 8 |
| 4 | Wellfleet Apartments | 48 | 8 |
| 5 | Harborside Village | 165 | 7 |
28 total water systems serve Barnstable County.
All ZIP Codes in Barnstable County
54 ZIP codes tracked in Barnstable County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 2562 | Sagamore Beach | 83 | B | 0 | $576K |
| 2 | 2541 | Falmouth | 78 | B | 3 (2 health) | — |
| 3 | 2635 | Cotuit | 78 | B | 0 | $650K |
| 4 | 2638 | Dennis | 78 | B | 0 | $714K |
| 5 | 2645 | Harwich | 78 | B | 0 | $581K |
| 6 | 2660 | South Dennis | 78 | B | 0 | $503K |
| 7 | 2652 | North Truro | 76 | B | 1 | $844K |
| 8 | 2653 | Orleans | 76 | B | 1 | $817K |
| 9 | 2655 | Osterville | 76 | B | 1 | $746K |
| 10 | 2666 | Truro | 76 | B | 1 | $671K |
| 11 | 2631 | Brewster | 74 | B | 3 | $622K |
| 12 | 2601 | Hyannis | 73 | B | 0 | $409K |
| 13 | 2633 | Chatham | 73 | B | 0 | $881K |
| 14 | 2664 | South Yarmouth | 73 | B | 1 | $479K |
| 15 | 2563 | Sandwich | 71 | B | 1 | $553K |
| 16 | 2630 | Barnstable | 71 | B | 1 | $686K |
| 17 | 2642 | Eastham | 71 | B | 1 | $668K |
| 18 | 2649 | Mashpee | 70 | B | 3 | $516K |
| 19 | 2667 | Wellfleet | 69 | C | 7 | $760K |
| 20 | 2673 | West Yarmouth | 69 | C | 2 | $445K |
| 21 | 2559 | Pocasset | 68 | C | 0 | $564K |
| 22 | 2657 | Provincetown | 68 | C | 0 | $770K |
| 23 | 2663 | South Wellfleet | 68 | C | 3 | $663K |
| 24 | 2540 | Falmouth | 63 | C | 3 (2 health) | $756K |
| 25 | 2561 | Sagamore | 63 | C | 0 | $462K |
| 26 | 2637 | Cummaquid | 63 | C | 0 | $861K |
| 27 | 2641 | East Dennis | 63 | C | 0 | $1025K |
| 28 | 2644 | Forestdale | 63 | C | 0 | $459K |
| 29 | 2647 | Hyannis Port | 63 | C | 0 | — |
| 30 | 2648 | Marstons Mills | 63 | C | 0 | $581K |
| 31 | 2659 | South Chatham | 63 | C | 0 | $650K |
| 32 | 2661 | South Harwich | 63 | C | 0 | — |
| 33 | 2672 | West Hyannisport | 63 | C | 0 | — |
| 34 | 2534 | Cataumet | 55 | C | 0 | $1011K |
| 35 | 2553 | Monument Beach | 55 | C | 0 | — |
| 36 | 2643 | East Orleans | 55 | C | 0 | — |
| 37 | 2646 | Harwich Port | 55 | C | 0 | $724K |
| 38 | 2650 | North Chatham | 55 | C | 0 | $974K |
| 39 | 2651 | North Eastham | 55 | C | 0 | — |
| 40 | 2662 | South Orleans | 55 | C | 0 | — |
| 41 | 2668 | West Barnstable | 55 | C | 0 | $622K |
| 42 | 2671 | West Harwich | 55 | C | 0 | $594K |
| 43 | 2675 | Yarmouth Port | 55 | C | 0 | $544K |
| 44 | 2542 | Buzzards Bay | 53 | D | 0 | — |
| 45 | 2634 | Centerville | 53 | D | 0 | — |
| 46 | 2669 | West Chatham | 53 | D | 0 | — |
| 47 | 2536 | East Falmouth | 50 | D | 0 | $497K |
| 48 | 2537 | East Sandwich | 50 | D | 0 | $618K |
| 49 | 2543 | Woods Hole | 50 | D | 0 | $909K |
| 50 | 2556 | North Falmouth | 50 | D | 0 | $659K |
| 51 | 2574 | West Falmouth | 50 | D | 0 | — |
| 52 | 2632 | Centerville | 50 | D | 0 | $542K |
| 53 | 2639 | Dennis Port | 50 | D | 0 | $452K |
| 54 | 2670 | West Dennis | 50 | D | 0 | $647K |
Recommended Buyer Guides for Barnstable County
Below: editorial picks, no sponsored placements.
- Best Lead Paint Test Kits — 72.3% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Barnstable County, Massachusetts
Overview
Barnstable County in Massachusetts covers 54 ZIP codes with an average Home Safety Score of C (64/100).
15 of 54 ZIP codes have recorded EPA violations. 4 health-based violations have been documented.
← Back to Massachusetts water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.