Tapcensus

Colorado

Boulder County drinking water quality

80 active public water systems serve 436,911 people in Boulder County. 35 are compliant, 45 had at least one EPA violation in the past three years, 1 is a designated serious violator, and 4 carry a health flag.

Active systems 80 41 community systems
People served 437K by public water systems
Systems with violations 45 56% of active systems, past 3 years
Serious violators 1 4 systems carry a health flag

Needs attention

Sans Souci Cooperative CO0107702 · Community water system · Serves 150 8 rules violated in the past three years. Unresolved: Groundwater Rule (GWR), Interim Enhanced Surface Water Treatment Rule, and Public Notification Rule.
Mile HI Water INC Hauler CO0107510 · Community water system · Serves 1,000 3 rules violated in the past three years. Unresolved: Consumer Confidence Rule (CCR), Groundwater Rule (GWR), and Public Notification Rule.
Camp Dick CG CO0307166 · Transient non-community system · Serves 328 2 rules violated in the past three years. Unresolved: Groundwater Rule (GWR).
Blue Leaf School LLC CO0207192 · Non-Transient non-community system · Serves 65 5 rules violated in the past three years. Unresolved: Groundwater Rule (GWR), Interim Enhanced Surface Water Treatment Rule, and Public Notification Rule.

Community water systems

41 systems, largest first
SystemServesStatusRules violated, 3 yrUnresolved
Boulder City of
 166,080 1 0
Longmont City of
 104,178 0 0
Erie Town of
 47,444 0 0
Lafayette City of
 28,700 4 0
Louisville City of
 20,975 1 0
Left Hand WD
 20,280 0 0
Superior MD NO 1
 17,900 0 0
Longs Peak WD
 3,200 0 0
Lyons Town of
 2,990 0 0
Nederland Town of
 2,406 0 0
Boulder Meadows MHP
 1,657 0 0
Pine Brook Hills WD
 1,100 0 0
Mile HI Water INC Hauler
 1,000 3 2
Arbordale Acres MHP
 901 5 0
Boulder Ridge MHP
 897 0 0
San Lazaro Mfctd Housing Community
 844 5 0
Baseline WD
 820 1 0
Countryside of Longmont
Longmont 		775 2 0
Vista Village MHP
Boulder 		750 1 0
Hoover Hills Wsd
 662 0 0
ST Vrain MHP LLC
Longmont 		544 0 0
Shannon Wsd
 450 0 0
Skylark Mobile Home Community
 342 3 0
Allenspark Wsd
 340 0 0
Eldorado Municipal System
 308 0 0
East Boulder County WD
 300 3 1
Jamestown Town of
 280 7 1
Grand Meadow of Longmont MHP
 255 3 0
Lefthand Wsd Lake Pines
 250 0 0
Olde Stage WD
 250 1 0
Ward Town of
 230 1 0
Mountain View MHP
 211 0 0
Lafayette Gardens
 207 0 0
Sans Souci Cooperative
 150 8 1
Spring Valley Mutual WA
 100 1 0
Meadow Mtn Water Supply
 76 2 0
Lark Meadows WA
 75 0 0
Lmp Coop MHP
 75 1 0
Table Mesa Village MHP
 75 1 0
Grace Mar Wua
 50 0 0
Maple Grove WD
 35 3 2
Non-community systems (39: schools, campgrounds, workplaces, restaurants)

These systems serve places people visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Eldora Mountain Resort
 2,400 1 0
Pawnee CG
 740 0 0
Fairview Conoco
 700 0 0
Eldora Mountain Restaurant
 510 1 0
Kelly Dahl CG
 368 0 0
Camp Dick CG
 328 2 1
Meeker Park Lodge
 270 3 0
Jacobs Corner
 250 1 0
Wild Basin ES
 250 0 0
Glacier View Ranch
 210 0 0
Eldorado Corner Market
 204 0 0
Girl Scouts Meadow Mtn Ranch
 175 0 0
Stone Mountain Lodge and Cabins
 160 4 1
Islamic Center of Boulder
 157 1 0
Rock Creek Farm WS
 151 2 0
CU Mountain Research Station
 140 2 0
Peaceful Valley CG
 136 0 0
Unitarian Universalist Church
 136 0 0
Canyon Tavern the
 128 1 0
Alpine Brook WS
 100 2 0
Gates Camp
 100 0 0
Gold Hill Inn
 100 0 0
Crystal Spring Water
 90 1 1
YMCA Camp Tumbleson Lake
 90 2 0
City on the Hill
 82 1 0
River Church
 82 2 0
Boulder Adventure Lodge
 81 0 0
Wild Basin Lodge
 74 1 1
Cal Wood
 66 2 1
Blue Leaf School LLC
 65 5 1
Highlands Camp and Retreat Center
 63 5 0
Sgry
 61 0 0
Wonder VU Cafe
 50 1 0
Ferncliff Food N Fuel
 47 1 0
Eldorado Canyon State Park
 40 0 0
Friends School
 39 0 0
Rocky Mtn Pathways Ranch
 39 2 0
Balarat Outdoor Laboratory
 38 1 1
Calvary Boulder Valley
 29 3 0
Inactive systems (152, no longer operating or reporting)

Kept for the record and excluded from the county totals above. Browse inactive systems.

About this data

Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.

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.