Water Quality Report · Updated May 12, 2026

WESTMINSTER CITY OF

Serving 202,078 residents in WESTMINSTER, Colorado .

National rank 66th percentile
Colorado rank 48th percentile
Data confidence Medium
Quick answer

WESTMINSTER CITY OF delivers tap water graded C (67/100) by TapWaterSafety.org. The utility serves approximately 202,078 residents in WESTMINSTER, Colorado using surface water. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Bromodichloromethane significantly above health guideline. For questions, the utility can be reached at 303-658-2374.

Data sources for this grade: utilities.csv EWG Tap Water Database ⓘ How did we get this rating?
202,078
People served
1
City served
23
Contaminants detected
12
Above health guidelines
0
EPA violations (5 yr)

Is WESTMINSTER tap water safe to drink?

WESTMINSTER CITY OF delivers tap water that earns a grade of C (67/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.

The utility serves 202,078 residents in WESTMINSTER, drawing from surface water.

Public testing data identifies 12 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Bromodichloromethane, Haloacetic acids (HAA5), Dibromochloromethane, Dibromoacetic acid, Chloroform, Trichloroacetic acid, Dichloroacetic acid, Chromium (hexavalent), Radium, combined (-226 and -228), Bromoform. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.

Top concerns in this water

Based on the most recent EPA and EWG data, these are the most significant water quality issues for WESTMINSTER CITY OF.

Haloacetic acids (HAA9) significantly above health guideline

Moderate concern

Haloacetic acids (HAA9) detected at 19.6 ppb, 327x above the EWG health guideline of 0.06 ppb.

Total trihalomethanes (TTHMs) significantly above health guideline

Moderate concern

Total trihalomethanes (TTHMs) detected at 32.8 ppb, 219x above the EWG health guideline of 0.15 ppb.

Bromodichloromethane significantly above health guideline

Moderate concern

Bromodichloromethane detected at 11.9 ppb, 198x above the EWG health guideline of 0.06 ppb.

Contact WESTMINSTER CITY OF

Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.

Recommended water filters for WESTMINSTER

Filters matched to the specific contaminants in this water supply.

Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.

Score breakdown

This utility's overall score of 67/100 breaks down across five weighted components. Read the full methodology →

Health Guideline Performance
10 / 40
Legal Compliance
20 / 20
High-Risk Contaminants
20 / 20
Compliance History
10 / 10
Source Water Vulnerability
7 / 10

Contaminants detected — international standards comparison

Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →

Contaminant Detected EWG
US health-based
EPA
US legal
EU DWD
Europe
WHO
global
CA PHG
strictest US
Tested
sample year
Status
Haloacetic acids (HAA9)
Disinfection byproduct
19.6 ppb 0.06 327× over
Total trihalomethanes (TTHMs)
Disinfection byproduct
32.8 ppb 0.15 80.0 100 219× over
Bromodichloromethane
Disinfection byproduct
11.9 ppb 0.06 198× over
Haloacetic acids (HAA5)
Disinfection byproduct
9.73 ppb 0.1 60.0 60 97× over
Dibromochloromethane
Disinfection byproduct
8.76 ppb 0.1 88× over
Dibromoacetic acid
Disinfection byproduct
1.48 ppb 0.03 49× over
Chloroform
Disinfection byproduct
11.0 ppb 0.4 28× over
Trichloroacetic acid
Disinfection byproduct
2.79 ppb 0.1 28× over
Dichloroacetic acid
Disinfection byproduct
5.44 ppb 0.2 27× over
Chromium (hexavalent)
Heavy metal
0.178 ppb 0.02 8.9× over
Radium, combined (-226 and -228)
Radiological
0.29 pCi/L 0.05 5.0 5.8× over
Bromoform
Disinfection byproduct
1.16 ppb 0.5 2.3× over
Uranium
Radiological
0.39 pCi/L 0.43 20.0 30 30 0.43 Below guideline
Chlorate
Disinfection byproduct
176.7 ppb 210.0 Below guideline
Molybdenum
Other
3.06 ppb 40.0 Below guideline
Barium
Heavy metal
46.3 ppb 700.0 2000.0 1300 2000 Below guideline
Manganese
Heavy metal
0.499 ppb 100.0 50 80 Below guideline
Vanadium
Other
0.015 ppb 21.0 Below guideline
Monochloroacetic acid
Disinfection byproduct
0.0219 ppb 53.0 Below guideline
Strontium
Radiological
0.191 ppb 1500.0 Below guideline
Chromium (total)
Heavy metal
0.347 ppb 100.0 Below guideline
Fluoride
Inorganic
0.577 ppm 4.0 1.5 1.5 Below guideline
Lithium
Other
20.4 ppb Below guideline

All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.

Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.

WESTMINSTER CITY OF service area

This water system serves 1 community in Adams County, Colorado. Click any city for its dedicated tap water quality page.

About this water system

Public Water System ID
CO0101170
Owner type
Local government
Source water
Surface water
Service connections
33,619
Service area
WESTMINSTER, Adams County, Colorado