Water Quality Report · Updated May 12, 2026

CASPER, CITY OF

Serving 59,000 residents in CASPER, Wyoming .

National rank 53th percentile
Wyoming rank 100th percentile
Data confidence Medium
D
64/100
Below Average
ⓘ How did we get this rating?
Quick answer

CASPER, CITY OF delivers tap water graded D (64/100) by TapWaterSafety.org. The utility serves approximately 59,000 residents in CASPER, Wyoming using surface water (purchased). The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Bromochloroacetic acid* significantly above health guideline; Total trihalomethanes (TTHMs)* significantly above health guideline. For questions, the utility can be reached at 307-235-8360.

Data sources for this grade: utilities.csv EWG Tap Water Database ⓘ How did we get this rating?
59,000
People served
1
City served
27
Contaminants detected
18
Above health guidelines
0
EPA violations (5 yr)

Is CASPER tap water safe to drink?

CASPER, CITY OF delivers tap water that earns a grade of D (64/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including haloacetic acids (haa9) significantly above health guideline.

The utility serves 59,000 residents in CASPER, drawing from surface water (purchased).

Public testing data identifies 18 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Bromochloroacetic acid*, Total trihalomethanes (TTHMs)*, Bromodichloromethane*, Haloacetic acids (HAA5)*, Bromate*, Dibromoacetic acid*, Dibromochloromethane*, Dichloroacetic acid*, Radium, combined (-226 and -228)*, Trichloroacetic acid*, Uranium*, Chloroform*, Nitrate and nitrite*, Chromium (hexavalent), Thallium*, Chlorate, 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 CASPER, CITY OF.

Haloacetic acids (HAA9) significantly above health guideline

Moderate concern

Haloacetic acids (HAA9) detected at 13.0 ppb, 217x above the EWG health guideline of 0.06 ppb.

Bromochloroacetic acid* significantly above health guideline

Moderate concern

Bromochloroacetic acid* detected at 2.58 ppb, 129x above the EWG health guideline of 0.02 ppb.

Total trihalomethanes (TTHMs)* significantly above health guideline

Moderate concern

Total trihalomethanes (TTHMs)* detected at 10.6 ppb, 71x above the EWG health guideline of 0.15 ppb.

Contact CASPER, CITY OF

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

Recommended water filters for CASPER

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 64/100 breaks down across five weighted components. Read the full methodology →

Health Guideline Performance
10 / 40
Legal Compliance
20 / 20
High-Risk Contaminants
17 / 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
13.0 ppb 0.06 217× over
Bromochloroacetic acid*
Disinfection byproduct
2.58 ppb 0.02 129× over
Total trihalomethanes (TTHMs)*
Disinfection byproduct
10.6 ppb 0.15 80.0 100 71× over
Bromodichloromethane*
Disinfection byproduct
3.69 ppb 0.06 61× over
Haloacetic acids (HAA5)*
Disinfection byproduct
5.54 ppb 0.1 60.0 60 55× over
Bromate*
Disinfection byproduct
5.38 ppb 0.1 10.0 10 10 0.1 54× over
Dibromoacetic acid*
Disinfection byproduct
1.39 ppb 0.03 46× over
Dibromochloromethane*
Disinfection byproduct
3.41 ppb 0.1 34× over
Dichloroacetic acid*
Disinfection byproduct
3.09 ppb 0.2 15× over
Radium, combined (-226 and -228)*
Radiological
0.75 pCi/L 0.05 5.0 15× over
Trichloroacetic acid*
Disinfection byproduct
0.814 ppb 0.1 8.1× over
Uranium*
Radiological
2.95 pCi/L 0.43 20.0 30 30 0.43 6.9× over
Chloroform*
Disinfection byproduct
2.73 ppb 0.4 6.8× over
Nitrate and nitrite*
Inorganic
0.266 ppm 0.14 10.0 11.3 11.3 10 1.9× over
Chromium (hexavalent)
Heavy metal
0.037 ppb 0.02 1.8× over
Thallium*
Heavy metal
0.16 ppb 0.1 2.0 1.6× over
Chlorate
Disinfection byproduct
307.0 ppb 210.0 1.5× over
Bromoform*
Disinfection byproduct
0.726 ppb 0.5 1.5× over
Manganese
Heavy metal
16.1 ppb 100.0 50 80 Below guideline
Selenium*
Heavy metal
1.2 ppb 30.0 50.0 20 40 30 Below guideline
Molybdenum
Other
1.53 ppb 40.0 Below guideline
Vanadium
Other
0.362 ppb 21.0 Below guideline
Monobromoacetic acid*
Disinfection byproduct
0.2 ppb 25.0 Below guideline
Monochloroacetic acid*
Disinfection byproduct
0.0411 ppb 53.0 Below guideline
Strontium
Radiological
0.55 ppb 1500.0 Below guideline
Fluoride*
Inorganic
0.32 ppm 4.0 1.5 1.5 Below guideline
Lithium
Other
38.6 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.

CASPER, CITY OF service area

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

About this water system

Public Water System ID
WY5601415
Owner type
Local government
Source water
Surface water (purchased)
Service connections
22,754
Service area
CASPER, Natrona County, Wyoming