WaterVerge

Is Buffalo, WY Tap Water Safe to Drink?

Graded B-, with 10 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

5K residents served 3 water systems PWSID: WY5600005
Overall Score
73.2 / 100
Violations
10 active
Last Updated
May 2026
Source
Surface water
#35 of 65 in Wyoming Top 65% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
B-GRADE
Water Quality Grade
73.2/100
waterverge.com
B- 73.2/100

Buffalo, WY — Water Quality Report

Buffalo's drinking water received a grade of B- (73.2 out of 100), indicating fair water quality. The city's 3 water systems serve approximately 4,598 residents using surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 65 violations on record, including 19 health-based violations. 10 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Buffalo's water

Buffalo ranks #35 out of 65 cities in Wyoming for water quality, placing it below average in the state.

The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.

The system has seen 8 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
73.2 out of 100 Grade B-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
25.2/45
D
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
16/20
B
No PFAS compounds detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Surface water.
Water Safety

Is Buffalo, WY water safe to drink?

Concerns Identified

Buffalo's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (73.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 4,598 residents using surface water (rivers, lakes, or reservoirs).

10
Active Violations
0.0 ppb
Lead (90th %ile)
None
PFAS Detected
2 events
Disaster History

Recent water quality updates for Buffalo

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Buffalo's water quality assessment. Grade: B- (73.2/100).

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Total Haloacetic Acids (HAA5).

Violation
2 drinking water violations recorded

2 health-based. Contaminants: Total Haloacetic Acids (HAA5).

Violation
2 drinking water violations recorded

2 health-based. Contaminants: Total Haloacetic Acids (HAA5).

Disaster
SEVERE STORMS AND FLOODING

Federal disaster declaration (FEMA DR-4227). Flood event — may have impacted local water infrastructure.

Disaster
SEVERE STORMS, FLOODING & MUDSLIDES

Federal disaster declaration (FEMA DR-557). Flood event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Buffalo's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Buffalo's water system has 65 total violations on record, including 19 health-based violations. 10 remain unresolved. 8 violations were issued in the last 5 years.

MCLMROtherTT
Most recent violations:
Jul 2024 Total Haloacetic Acids (HAA5) Resolved
Apr 2024 Total Haloacetic Acids (HAA5) Resolved
Apr 2024 Total Haloacetic Acids (HAA5) Resolved
Jan 2024 Total Haloacetic Acids (HAA5) Resolved
Jan 2024 Total Haloacetic Acids (HAA5) Resolved

Flood & environmental risk

Johnson County has experienced 2 federally declared disasters since 1978. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Clear Creek.

SEVERE STORMS AND FLOODING
Flood FEMA DR-4227
SEVERE STORMS, FLOODING & MUDSLIDES
Flood FEMA DR-557

Where does Buffalo's water come from?

Buffalo's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 3 water systems serving approximately 4,598 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Clear Creek (river).

What Buffalo residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Buffalo's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
0
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

65
Total violations
19
Health-based
10
Active / unresolved
Jul 2024
Most recent violation
Compliance Record

Violations & advisories

65 Total
10 Active
19 Health-based
55 Resolved
1 SNC
Violations by category
Total Coliform Rule
13
Inorganic Chemicals
12
Stage 2 Disinfectants and Disinfection Byproducts Rule
9
Nitrate Rule
8
Surface Water Treatment Rule
5
Oct 2022 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Dec 2020 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Oct 2015 Active
Consumer Confidence Rule
Other Violation 0
Jul 2014 Active
Consumer Confidence Rule
Other Violation 0
Jul 2013 Active
Consumer Confidence Rule
Other Violation 0
Oct 2008 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Oct 2000 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Active
Compliance Violation
Monitoring 0
Active
Compliance Violation
Monitoring 0
Jul 2024 Resolved
Total Haloacetic Acids (HAA5)
Max Contaminant Level
Health-Based Health Resolved Sep 2024
Apr 2024 Resolved
Total Haloacetic Acids (HAA5)
Max Contaminant Level
Health-Based Health Resolved Jun 2024
Apr 2024 Resolved
Total Haloacetic Acids (HAA5)
Max Contaminant Level
Health-Based Health Resolved Jun 2024
Jan 2024 Resolved
Total Haloacetic Acids (HAA5)
Max Contaminant Level
Health-Based Health Resolved Mar 2024
Jan 2024 Resolved
Total Haloacetic Acids (HAA5)
Max Contaminant Level
Health-Based Health Resolved Mar 2024
Oct 2023 Resolved
Total Haloacetic Acids (HAA5)
Max Contaminant Level
Health-Based Health Resolved Dec 2023
Jul 2021 Resolved
Total Haloacetic Acids (HAA5)
Monitoring & Reporting
SNC Monitoring & Reporting Resolved Sep 2021
Feb 2018 Resolved
TTHM
Monitoring & Reporting
Monitoring & Reporting Resolved Apr 2018
Feb 2018 Resolved
Total Haloacetic Acids (HAA5)
Monitoring & Reporting
Monitoring & Reporting Resolved Apr 2018
Dec 2014 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2014
Showing 20 of 65 violations
Environmental Risk

Drought conditions

D3 — extreme drought

Johnson County is currently in D3 (extreme drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.

12
Weeks at D2+ (current streak)
33.8%
Months in D2+ (last 30y)
12
Weeks at D2+ (last 5y)

Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.

Environmental Risk

Flood & disaster history

2
Declared disasters
Jul 2015
Most recent
Flood
Most common type

Johnson County has experienced 2 federally declared disasters since 1978. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Jul 2015
SEVERE STORMS AND FLOODING
Flood FEMA #4227
May 1978
SEVERE STORMS, FLOODING & MUDSLIDES
Flood FEMA #557

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium ND HI µg/L PFAS Not Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 32.0 ppb from 1992 (32.0 ppb) to 2025 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Surface Water
Operator
Local Government
Population Served
4,598
Water Systems
3
Source breakdown
Groundwater
2
Surface Water
1
Water Source

Where Buffalo's water comes from

Surface Water

Buffalo's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.

Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.

These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.

The system is operated by local government ownership and serves approximately 4,598 people through 3 water systems.

Local Hydrology

Water bodies near Buffalo

Buffalo is located near 1 notable water body. As a surface water system, these water bodies may directly influence the city's drinking water supply.

Clear Creek
river
Infrastructure

Water systems serving Buffalo

System Name PWSID Population Source
BUFFALO, CITY OF WY5600005 4,419 SW
BALD MOUNTAIN TRAILER COURT WY5600258 150 GW
BIGHORN MOUNTAIN CAMPGROUND WY5600229 29 GW
Regional Comparison

How Buffalo compares

Full Wyoming rankings →

Buffalo's score of 73.2/100 is above the average of 55/100 among major Wyoming cities. It outscores 8 of 10 nearby cities.

Buffalo (this city)
73.2
Cheyenne
30.8
Casper
41.8
Gillette
44.5
Laramie
55.2
Jackson
43.2
Wyoming avg
55
City Profile

About Buffalo, WY

Wikipedia →

Buffalo is a city in and the county seat of Johnson County, Wyoming, United States. The population was 4,415 at the 2020 census, down from 4,585 at the 2010 census. The city had experienced an economic boom due to methane production from the Coal Bed Methane Extraction method used in the Powder River Basin and surrounding areas. With the decline of methane production, Buffalo's population has stabilized since the 2010 Census. Even though energy is a vital part of its economy, agriculture, tourism, and recreation are three other major components. Buffalo is located at the foot of the Bighorn Mountains. The city is located almost equidistant between Yellowstone National Park and Mount Rushmore.

Economic Profile
$55,245
Median Income
$266,087
Median Home Value
$919/mo
Median Rent
4%
Unemployment
Community
49
Median Age
381
People / sq mi
35%
College Educated
64.2%
Homeownership
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Frequently asked questions

Is Buffalo, WY tap water safe to drink?

Buffalo's water quality earned a grade of B- (73.2/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #35 out of 65 cities tested in Wyoming.

What contaminants are in Buffalo's water?

Lead was measured at 0.0 ppb (90th percentile). No PFAS compounds were detected. 65 violations are on record.

How is Buffalo's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Buffalo?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Buffalo's water come from?

Buffalo's water is sourced from Surface water. The city has 3 water systems serving approximately 4,598 residents.

What health violations has Buffalo's water system had?

Buffalo has 19 health-based violations on record. The most recent violation was recorded in July 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 10 violations remain unresolved.

How does Buffalo's water compare to other cities?

Buffalo ranks #35 out of 65 cities in Wyoming (better than 46% of state cities) and #10134 out of 15744 cities nationally (36th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.