Water quality in Longmont, Colorado
Longmont is in Boulder County. 80 active public water systems serve the county; 45 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 Boulder County
40 systems, nearest first| System | Serves | Status | Rules violated, 3 yr | Distance |
|---|---|---|---|---|
| Countryside of Longmont Longmont |
775 | 2 | under 0.1 mi | |
| ST Vrain MHP LLC Longmont |
544 | 0 | under 0.1 mi | |
| Longs Peak WD |
3,200 | 0 | 3.6 mi | |
| Left Hand WD |
20,280 | 0 | 4.4 mi | |
| Erie Town of |
47,444 | 0 | 9.8 mi | |
| Lyons Town of |
2,990 | 0 | 10.0 mi | |
| Lefthand Wsd Lake Pines |
250 | 0 | 10.1 mi | |
| Mile HI Water INC Hauler |
1,000 | 3 | 10.1 mi | |
| San Lazaro Mfctd Housing Community |
844 | 5 | 10.9 mi | |
| Boulder Meadows MHP |
1,657 | 0 | 10.9 mi | |
| Shannon Wsd |
450 | 0 | 11.0 mi | |
| Lark Meadows WA |
75 | 0 | 11.5 mi | |
| Olde Stage WD |
250 | 1 | 12.0 mi | |
| Baseline WD |
820 | 1 | 12.0 mi | |
| Lafayette City of |
28,700 | 4 | 12.1 mi | |
| Hoover Hills Wsd |
662 | 0 | 12.3 mi | |
| Boulder City of |
166,080 | 1 | 12.6 mi | |
| Vista Village MHP Boulder |
750 | 1 | 12.8 mi | |
| Spring Valley Mutual WA |
100 | 1 | 13.4 mi | |
| East Boulder County WD |
300 | 3 | 13.8 mi | |
| Pine Brook Hills WD |
1,100 | 0 | 13.9 mi | |
| Louisville City of |
20,975 | 1 | 13.9 mi | |
| Maple Grove WD |
35 | 3 | 14.2 mi | |
| Table Mesa Village MHP |
75 | 1 | 15.5 mi | |
| Jamestown Town of |
280 | 7 | 15.8 mi |
Non-community systems in Boulder County (39: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
About this data
Water systems are matched to Boulder County, nearest to Longmont 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 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 Colorado 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.