WaterVerge

Is Sundance, WY Tap Water Safe to Drink?

Graded A-, with 8 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

1K residents served 2 water systems PWSID: WY5600055
Overall Score
87.7 / 100
Violations
8 active
Last Updated
May 2026
Source
Groundwater
#16 of 65 in Wyoming Top 25% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
A-GRADE
Water Quality Grade
87.7/100
waterverge.com
A- 87.7/100

Sundance, WY — Water Quality Report

Sundance's drinking water received a grade of A- (87.7 out of 100), indicating good water quality. The city's 2 water systems serve approximately 1,399 residents using groundwater.

Lead levels were measured at 2.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.

The system has 36 violations on record, including 10 health-based violations. 8 remain unresolved.

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

What to know about Sundance's water

Sundance ranks #16 out of 65 cities in Wyoming for water quality, placing it above average in the state.

Sundance relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.

As a small community water system, Sundance may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.

Quality Breakdown

Water quality score

See methodology →
87.7 out of 100 Grade A-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
40.7/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 2.0 ppb (90th percentile).
Contaminants
17/20
B
PFAS + legacy contaminant analysis.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Sundance, WY water safe to drink?

Concerns Identified

Sundance's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (87.7/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,399 residents using groundwater (wells).

8
Active Violations
2.0 ppb
Lead (90th %ile)
1 event
Disaster History

Recent water quality updates for Sundance

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Sundance's water quality assessment. Grade: A- (87.7/100).

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Groundwater Rule.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

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 Sundance's water supply.

Lead Within Limits
Detected: 2.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Sundance's water system has 36 total violations on record, including 10 health-based violations. 8 remain unresolved.

TTMCLMROther
Most recent violations:
Jul 2019 Groundwater Rule Open
Sep 2013 Coliform (TCR) Resolved
Aug 2013 Coliform (TCR) Resolved
Jan 2012 Lead and Copper Rule Open
Jul 2010 E. COLI Open

Flood & environmental risk

Crook County has experienced 1 federally declared disaster 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.

SEVERE STORMS, FLOODING & MUDSLIDES
Flood FEMA DR-557

Where does Sundance's water come from?

Sundance's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 1,399 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.

What Sundance residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Sundance'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
2.0 ppb
EPA Action Level: 15 ppb · 13% of limit
Safe Level
Compliance Record

Violation summary

36
Total violations
10
Health-based
8
Active / unresolved
Jul 2019
Most recent violation
Compliance Record

Violations & advisories

36 Total
8 Active
10 Health-based
28 Resolved
Violations by category
Total Coliform Rule
14
Surface Water Treatment Rule
7
Lead and Copper Rule
3
Radionuclides and Revised Rad Rule
3
Ground Water Rule
2
Jul 2019 Active
Groundwater Rule
Treatment Technique
Health-Based Health 0
Jan 2012 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2010 Active
E. COLI
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2008 Active
Consumer Confidence Rule
Other Violation 0
Jan 2001 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jan 1995 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Active
Compliance Violation
Monitoring 0
Sep 2013 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Sep 2013
Aug 2013 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Aug 2013
May 2010 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved May 2010
Jul 2009 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2009
Jan 2005 Resolved
Nitrate
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2005
Aug 2004 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Aug 2004
Jul 2004 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2004
Feb 2004 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Feb 2004
Apr 2003 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Apr 2003
Jan 2003 Resolved
Nitrate
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2003
Oct 2002 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Oct 2002
Jul 2001 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Jul 2001
Showing 20 of 36 violations
Environmental Risk

Drought conditions

D2 — severe drought

Crook County is currently in D2 (severe 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.

3
Weeks at D2+ (current streak)
21.7%
Months in D2+ (last 30y)
3
Weeks at D2+ (last 5y)

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

Environmental Risk

Flood & disaster history

1
Declared disasters
May 1978
Most recent
Flood
Most common type

Crook County has experienced 1 federally declared disaster since 1978. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

May 1978
SEVERE STORMS, FLOODING & MUDSLIDES
Flood FEMA #557

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 2.0 15 ppb Inorganic Safe
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has increased by 3.0 ppb from 2003 (0.0 ppb) to 2025 (3.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
1,399
Water Systems
2
Water Source

Where Sundance's water comes from

Groundwater

Sundance's drinking water is drawn from underground aquifers through wells.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.

Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.

The system is operated by local government ownership and serves approximately 1,399 people through 2 water systems.

Infrastructure

Water systems serving Sundance

System Name PWSID Population Source
SUNDANCE, CITY OF WY5600055 1,279 GW
VISTA WEST IMPROVEMENT & SERV DISTRICT WY5600246 120 GW
Regional Comparison

How Sundance compares

Full Wyoming rankings →

Sundance's score of 87.7/100 is above the average of 55/100 among major Wyoming cities. It outscores 10 of 10 nearby cities.

Sundance (this city)
87.7
Cheyenne
30.8
Casper
41.8
Gillette
44.5
Laramie
55.2
Jackson
43.2
Wyoming avg
55
City Profile

About Sundance, WY

Wikipedia →

Sundance is a town in and the county seat of Crook County, Wyoming, United States. Its population was 1,032 at the 2020 census. The town is named after the Sun Dance ceremony practiced by several American Indian tribes.

Economic Profile
$54,167
Median Income
$260,049
Median Home Value
0%
Unemployment
Community
34.6
Median Age
139
People / sq mi
26.1%
College Educated
65.5%
Homeownership
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Frequently asked questions

Is Sundance, WY tap water safe to drink?

Sundance's water quality earned a grade of A- (87.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #16 out of 65 cities tested in Wyoming.

What contaminants are in Sundance's water?

Lead was measured at 2.0 ppb (90th percentile). 36 violations are on record.

How is Sundance'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 Sundance?

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

Where does Sundance's water come from?

Sundance's water is sourced from Groundwater. The city has 2 water systems serving approximately 1,399 residents.

What health violations has Sundance's water system had?

Sundance has 10 health-based violations on record. The most recent violation was recorded in July 2019. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 8 violations remain unresolved.

Is Sundance's groundwater at risk of contamination?

Sundance uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 36 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Sundance's water compare to other cities?

Sundance ranks #16 out of 65 cities in Wyoming (better than 75% of state cities) and #3893 out of 15744 cities nationally (75th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.