County · Massachusetts
Barnstable County, Massachusetts: drinking water records
This overview covers 47 ZIP codes and 32 community water systems in Barnstable County. It also stands in for 1 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Falmouth Water Dept MA4096000 | 97,551 | 306 | 0 | 1 | 1.1 ppb |
| Yarmouth Water Department MA4351000 | 38,900 | 899 | 5 | 1 | 1.5 ppb |
| Otis Air National Guard Base MA4096001 | 6,000 | 60 | 0 | 2 | 1.5 ppb |
| Dennis Water District MA4075000 | 65,000 | 540 | 2 | 0 | 0 ppb |
| Centerville Osterville Marstons Mills WD MA4020002 | 50,000 | 900 | 5 | 0 | 2.4 ppb |
| Harwich Water Department MA4126000 | 39,144 | 300 | 0 | 0 | 0 ppb |
| Mashpee Water District MA4172039 | 36,922 | 360 | 1 | 0 | 1.4 ppb |
| Brewster Water Department MA4041000 | 35,000 | 300 | 0 | 0 | 3.4 ppb |
| Hyannis Water System, Town of Barnstable MA4020004 | 35,000 | 180 | 3 | 0 | 0 ppb |
| Chatham Water Department MA4055000 | 30,000 | 300 | 0 | 0 | 1.1 ppb |
| Sandwich Water District MA4261000 | 23,000 | 600 | 0 | 0 | 0 ppb |
| Bourne Water District MA4036000 | 22,500 | 390 | 3 | 0 | 4.4 ppb |
| Provincetown Water Department MA4242000 | 22,250 | 120 | 0 | 0 | 2 ppb |
| Orleans Water Department MA4224000 | 17,460 | 120 | 0 | 0 | 0 ppb |
| Buzzards Bay Water District MA4036001 | 7,700 | 300 | 0 | 0 | 1 ppb |
| Town of Eastham MA4086095 | 6,199 | 120 | 0 | 0 | 0 ppb |
| Barnstable Fire District MA4020000 | 5,400 | 180 | 6 | 0 | 1.4 ppb |
| Cotuit Fire District Water Department MA4020003 | 4,938 | 300 | 0 | 0 | 3.1 ppb |
| North Sagamore Water District MA4036002 | 4,668 | 120 | 2 | 0 | 1 ppb |
| Wellfleet Municipal Water System MA4318094 | 750 | 0 | 0 | 1 | 3 ppb |
| Upper Cape Regional Water Cooperative MA4261024 | 56,250 | 180 | 0 | 0 | not reported |
| Barnstable County Jail MA4036015 | 600 | 0 | 0 | 0 | 5 ppb |
| Sea Oaks Condominiums MA4172033 | 222 | 0 | 0 | 0 | 1.4 ppb |
| Pleasant Water MA4318091 | 200 | 0 | 0 | 0 | 1.9 ppb |
| Sandy Bottom Estates MHP ME0095615 | 168 | 0 | 0 | 0 | 2.5 ppb |
ZIP reports in Barnstable County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 02666.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.