Tap Water Lookup

County · Colorado

Boulder County, Colorado: drinking water records

Explore EPA records for 41 community water systems across 18 ZIP codes in Boulder County, then find water-testing resources and available recent monitoring-station readings.

In focus41Community water systems
Public records. Clearer context.

Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages

Drinking-water records

EPA survey and compliance records are historical reports. UCMR 5 results are available for 7 of the 41 listed systems in this snapshot. A system with no reported PFAS detection is not a test of every tap or every contaminant.

7
systems in EPA's PFAS survey
0
systems where PFAS was found
0
systems at or above the PFOA or PFOS limit, on the yearly-average basis EPA uses
10
systems that have reached the lead action level
12
systems with a health-based violation since 2016

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 in this county

All 41 active community systems in the available county records, sorted by record completeness. Scroll the table to explore more systems.

Water systemPeople servedPFAS survey resultsPFAS foundHealth-based violationsLead, 9 in 10 homes at or below
Boulder City of CO0107152166,080240022 ppb
Louisville City of CO010748720,975240020 ppb
Superior Md No 1 CO010772517,900120020 ppb
Longmont City of CO0107485104,178120001.6 ppb
Erie Town of CO016225547,444120002.6 ppb
Lafayette City of CO010747328,700240002 ppb
Left Hand WD CO010747120,280240001 ppb
Arbordale Acres MHP CO01071189010010 ppb
San Lazaro Mfctd Housing Community CO01077018440020 ppb
Vista Village MHP CO01078107500014 ppb
Allenspark WSD CO01071153400034 ppb
Jamestown Town of CO01074012800042 ppb
Sans Souci Cooperative CO010770215000152.5 ppb
Spring Valley Mutual Wa CO01077191000021 ppb
Table Mesa Village MHP CO01077337500110 ppb
Longs Peak WD CO01074863,2000002 ppb
Lyons Town of CO01074962,9900000 ppb
Nederland Town of CO01075382,4060001 ppb
Boulder Meadows MHP CO01071791,6570000 ppb
Pine Brook Hills WD CO01076101,1000000 ppb
Mile Hi Water INC Hauler CO01075101,000003not reported
Boulder Ridge MHP CO01071538970000 ppb
Baseline WD CO01071358200000 ppb
Countryside of Longmont CO01071847750000 ppb
Hoover Hills WSD CO01073526620000 ppb
St Vrain MHP LLC CO01077245440000 ppb
Shannon WSD CO01077104500002 ppb
Skylark Mobile Home Community CO01077123420000 ppb
Eldorado Municipal System CO01072463080002 ppb
East Boulder County WD CO01072363000000 ppb
Grand Meadow of Longmont MHP CO01073222550000 ppb
Lefthand WSD Lake Pines CO01074722500004 ppb
Olde Stage WD CO01075822500002 ppb
Ward Town of CO01078342300002 ppb
Mountain View MHP CO01075172110003 ppb
Lafayette Gardens CO01074662070000 ppb
Meadow Mtn Water Supply CO0207504760001.5 ppb
Lark Meadows Wa CO01074897500010 ppb
Lmp Coop MHP CO0107483750000 ppb
Grace Mar Wua CO0107321500000 ppb
Maple Grove WD CO0107502350001 ppb

USGS · Monitoring stations

The water, more recently.

Available station readings in Boulder County, Colorado. Each measurement keeps its time, unit and original source.

These readings describe water at a monitoring station. They do not test your tap, measure PFAS or lead, or determine whether water is safe to drink or swim in.

Recent observations load when this section comes into view.

Station coverage and available measurements vary by county.

Explore USGS Water Data
How these readings update

We check for updates every 10 minutes while this section is visible and show supported observations from the last 48 hours. The time beside a reading is when USGS measured it; the checked time is when our service retrieved the response. We mark a reading more than 6 hours old as older. Provisional observations can change after USGS review. A missing reading does not mean zero or clean water.

Temperature, pH, dissolved oxygen, turbidity, conductivity, streamflow and water level are shown only where a station reports them. Different measurements have different units and sampling intervals. USGS data and documentation.

Your next step

Water testing, reports & local help.

Use these official directories to find your drinking-water agency, a certified laboratory and public water records. We have not yet added an individually reviewed local resource list for this county.

Official national directories

Water testing

Find your state’s private-well program

EPA’s state directory points well owners to local program information. Services and eligibility vary by state and county.

U.S. Environmental Protection Agency
Source reviewed · Source updated

Water testing

Find a certified drinking-water laboratory

Use EPA’s directory to reach your state’s laboratory certification program. EPA does not provide on-request testing of residential drinking water.

U.S. Environmental Protection Agency
Source reviewed · Source updated

Public records

Find your utility’s Consumer Confidence Report

EPA links to community water-system reports and explains how to read them. Look for your actual supplier rather than assuming every address in a county shares one system.

U.S. Environmental Protection Agency
Source reviewed · Source updated

Public records

Explore USGS water observations

Find current and historical observations from USGS monitoring locations, including available stream, lake, and groundwater data. Measurements vary by station and do not replace a test of your household water.

U.S. Geological Survey
Source reviewed

A county overview cannot identify every property’s water provider. If you use a public water system, confirm its name on your bill and request its annual Consumer Confidence Report. Private wells need their own testing; public-system records do not describe a private well.

Understand water testing and laboratory reports

Resource descriptions are compiled by Tap Water Lookup. Review dates describe our source check, not a new water sample. How we review sources · Suggest a correction

Explore your area

Local coverage in Boulder County

18ZIP areas in this overview

Explore the water-system records, recent station readings and testing resources on this county page. They describe the systems and stations identified in each section; they are not a separate water test for every community.

Towns and communities

  • Allenspark
  • Bark Ranch
  • Boulder
  • Eldora
  • Eldorado Springs
  • Glendale
  • Lafayette
  • Lazy Acres
  • Longmont
  • Louisville
  • Niwot
Explore water-system recordsFind water-testing resources
View ZIP areas and understand coverage
  • 80025Eldorado Springs
  • 80026Lafayette
  • 80027Louisville
  • 80301Boulder
  • 80302Lazy Acres
  • 80303Boulder
  • 80304Boulder
  • 80305Boulder
  • 80310Boulder
  • 80455Glendale
  • 80466Eldora
  • 80471
  • 80481Bark Ranch
  • 80501Longmont
  • 80503Longmont
  • 80510Allenspark
  • 80540Allenspark
  • 80544Niwot

These Census ZIP Code Tabulation Areas are grouped here by their largest county overlap. A ZIP area can cross county lines and contain several water suppliers or private wells. Place labels reflect Census geography, not verified postal city names or utility service boundaries.

Records for these areas are currently presented in this county overview rather than individual ZIP reports. An unpublished report does not mean there are no water records. Confirm your supplier on your water bill; if you use a private well, testing your own well is the relevant next step.

Beyond this county page

Keep reading. Compare nearby.

PFASReading PFAS survey resultsWhat a detection, a reporting level and a yearly average mean in EPA’s PFAS survey records.LeadChoosing a lead filter10 systems here have reached the lead action level. See how to check a filter’s lead-reduction certification.Your utilityFind your annual water reportConfirm the supplier on your bill, then read its Consumer Confidence Report for local results.

Counties near Boulder County

All Colorado counties

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. Database prepared 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.

Compiled by Tap Water Lookup from the sources identified on this page. Read the methodology and review process.

Keep exploring

Every record tells
part of the story.

Find a place. Read the measurements.
Understand the context.

Explore water records