Water quality in Dennis, Massachusetts
Dennis is in Barnstable County. 124 active public water systems serve the county; 30 had an EPA violation in the past three years.
Most likely your provider
Your location is within the outer bounds of this system's EPA service area.
Other community water systems in Barnstable County
29 systems, nearest first| System | Serves | Status | Rules violated, 3 yr | Distance |
|---|---|---|---|---|
| Dennis Water District Dennis |
65,000 | 0 | under 0.1 mi | |
| Harwich Water Department Harwich |
39,144 | 0 | 5.2 mi | |
| Brewster Water Department Brewster |
35,000 | 2 | 5.7 mi | |
| Barnstable Fire District Barnstable |
5,400 | 0 | 7.0 mi | |
| Hyannis Water System, Town of Barnstable Barnstable |
35,000 | 1 | 7.9 mi | |
| Chatham Water Department Chatham |
30,000 | 0 | 9.3 mi | |
| Orleans Water Department Orleans |
17,460 | 1 | 10.6 mi | |
| Centerville Osterville Marstons Mills WD Barnstable |
50,000 | 2 | 12.0 mi | |
| Town of Eastham Eastham |
6,199 | 0 | 12.9 mi | |
| Massasoit Hills Trailer Park Wellfleet |
120 | 1 | 14.7 mi | |
| Cotuit Fire District Water Department Barnstable |
4,938 | 0 | 15.3 mi | |
| Beechwood Point Condos Mashpee |
112 | 1 | 15.6 mi | |
| Sandwich Water District Sandwich |
23,000 | 1 | 16.2 mi | |
| Pleasant Water Wellfleet |
200 | 1 | 16.3 mi | |
| Sea Oaks Condominiums Mashpee |
222 | 0 | 16.6 mi | |
| Harborside Village Wellfleet |
165 | 0 | 16.8 mi | |
| Wellfleet Apartments Wellfleet |
48 | 1 | 17.1 mi | |
| Wellfleet Municipal Water System Wellfleet |
750 | 1 | 17.5 mi | |
| Upper Cape Regional Water Cooperative Sandwich |
56,250 | 0 | 17.5 mi | |
| Mashpee Water District Mashpee |
36,922 | 0 | 17.9 mi | |
| Otis Air National Guard Base Falmouth |
6,000 | 2 | 18.7 mi | |
| North Sagamore Water District Bourne |
4,668 | 0 | 20.0 mi | |
| Barnstable County Jail Bourne |
600 | 1 | 21.1 mi | |
| Schooner Pass Trustees Condominiums Bourne |
136 | 0 | 21.4 mi | |
| Stones Throw Condos Truro |
80 | 0 | 21.7 mi |
Non-community systems in Barnstable County (94: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
About this data
Water systems are matched to Barnstable County, nearest to Dennis first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system or, for systems without one, to the centre of the first town EPA lists the system as serving, from Census Bureau county subdivision files or the centre of the first town EPA lists the system as serving, from Census Bureau place files.
Town locations and ZIP code areas come from U.S. Census Bureau 2020 files.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Massachusetts records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.