WaterVerge

Is Eagle Butte, SD 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 ↓

2K residents served 1 water system PWSID: SD4600112
Overall Score
86.2 / 100
Violations
8 active
Last Updated
May 2026
Source
Surface water
#67 of 141 in South Dakota Top 31% nationally
Private
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
A-GRADE
Water Quality Grade
86.2/100
waterverge.com
A- 86.2/100

Eagle Butte, SD — Water Quality Report

Eagle Butte's drinking water received a grade of A- (86.2 out of 100), indicating good water quality. The city's 1 water system serves approximately 2,190 residents using surface water.

Lead levels were measured at 4.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 67 violations on record, including 15 health-based violations. 8 remain unresolved.

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

What to know about Eagle Butte's water

Eagle Butte ranks #67 out of 141 cities in South Dakota for water quality, placing it mid-range 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.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

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

Quality Breakdown

Water quality score

See methodology →
86.2 out of 100 Grade A-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
38.9/45
B
Historical violation record including health-based and monitoring violations.
Lead & Copper
18/20
A
Lead at 4.0 ppb (90th percentile).
Contaminants
17.2/20
B
1 PFAS compound detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Surface water.
Water Safety

Is Eagle Butte, SD water safe to drink?

Concerns Identified

Eagle Butte's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (86.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 2,190 residents using surface water (rivers, lakes, or reservoirs).

8
Active Violations
4.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected
4 events
Disaster History

Recent water quality updates for Eagle Butte

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

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Eagle Butte's water quality assessment. Grade: A- (86.2/100).

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Violation
1 drinking water violation recorded

Contaminants: Chlorine.

Disaster
SEVERE WINTER STORM, SNOWSTORM, AND FLOODING

Federal disaster declaration (FEMA DR-4440). Flood event — may have impacted local water infrastructure.

Disaster
SEVERE STORMS, TORNADOES, AND FLOODING

Federal disaster declaration (FEMA DR-4186). Flood event — may have impacted local water infrastructure.

Key contaminant findings

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

Lead Within Limits
Detected: 4.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 64.8000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Violation history

Eagle Butte's water system has 67 total violations on record, including 15 health-based violations. 8 remain unresolved. 2 violations were issued in the last 5 years.

MONMROtherTTMCL
Most recent violations:
Dec 2022 Revised Total Coliform Rule Resolved
Oct 2022 Chlorine Resolved
Mar 2009 Interim Enhanced Surface Water Treatment Rule Resolved
Dec 2008 Interim Enhanced Surface Water Treatment Rule Resolved

Flood & environmental risk

Dewey County has experienced 4 federally declared disasters since 1997. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.

SEVERE WINTER STORM, SNOWSTORM, AND FLOODING
Flood FEMA DR-4440
SEVERE STORMS, TORNADOES, AND FLOODING
Flood FEMA DR-4186
HURRICANE KATRINA EVACUATION
Coastal Storm FEMA DR-3234

Where does Eagle Butte's water come from?

Eagle Butte's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 2,190 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.

What Eagle Butte residents can do

Install a water filter

Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Eagle Butte'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.

Flush your taps

Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.

Monitor alerts during storms

Eagle Butte's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

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
4.0 ppb
EPA Action Level: 15 ppb · 27% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
64.8000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
Lithium
Inorganic
Above state screening
64.8 µg/L
State screening level: 60 µg/L · +8% over limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

67
Total violations
15
Health-based
8
Active / unresolved
Dec 2022
Most recent violation
Compliance Record

Violations & advisories

67 Total
8 Active
15 Health-based
59 Resolved
Violations by category
Synthetic Organic Chemicals
33
Stage 1 Disinfectants and Disinfection Byproducts Rule
14
Interim and Long Term 1 Enhanced Surface Water Treatment Rule
4
Total Coliform Rule
4
Public Notice Rule and Revised PN Rule
3
May 2013 Active
Ground Water Rule
Other Violation 0
Apr 2006 Active
Public Notice
Other Violation 0
Jan 2006 Active
Public Notice
Other Violation 0
Oct 2005 Active
Consumer Confidence Rule
Other Violation 0
Jul 2005 Active
Public Notice
Other Violation 0
Jun 2004 Active
Total Coliform Rule
Other Violation 0
Oct 2003 Active
Consumer Confidence Rule
Other Violation 0
Active
Compliance Violation
Monitoring 0
Dec 2022 Resolved
Revised Total Coliform Rule
Monitoring
Monitoring Resolved Dec 2022
Oct 2022 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2022
Mar 2009 Resolved
Interim Enhanced Surface Water Treatment Rule
Treatment Technique
Health-Based Health Resolved Mar 2009
Dec 2008 Resolved
Interim Enhanced Surface Water Treatment Rule
Treatment Technique
Health-Based Health Resolved Dec 2008
Nov 2006 Resolved
Interim Enhanced Surface Water Treatment Rule
Treatment Technique
Health-Based Health Resolved Nov 2006
Apr 2006 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Jun 2006
Jan 2006 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Mar 2006
Oct 2005 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Dec 2005
Jul 2005 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Sep 2005
Apr 2005 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Jun 2005
Apr 2005 Resolved
Interim Enhanced Surface Water Treatment Rule
Treatment Technique
Health-Based Health Resolved Apr 2005
Apr 2005 Resolved
Total Haloacetic Acids (HAA5)
Max Contaminant Level
Health-Based Health Resolved Jun 2005
Showing 20 of 67 violations
Environmental Risk

Flood & disaster history

4
Declared disasters
Jun 2019
Most recent
Flood
Most common type

Dewey County has experienced 4 federally declared disasters since 1997. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Jun 2019
SEVERE WINTER STORM, SNOWSTORM, AND FLOODING
Flood FEMA #4440
Jul 2014
SEVERE STORMS, TORNADOES, AND FLOODING
Flood FEMA #4186
Sep 2005
HURRICANE KATRINA EVACUATION
Coastal Storm FEMA #3234
Apr 1997
SEVERE FLOODING, SEVER WINTER STORMS,HEAVY RAINS HIGH WINDS
Flood FEMA #1173

Recommended water filters

Based on contaminants detected in Eagle Butte's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 4.0 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 64.800 HI µg/L PFAS 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 increased by 2.0 ppb from 1993 (2.0 ppb) to 2023 (4.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Surface Water
Operator
Private
Population Served
2,190
Water Systems
1
Water Source

Where Eagle Butte's water comes from

Surface Water

Eagle Butte'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 private ownership and serves approximately 2,190 people through 1 water system.

Infrastructure

Water systems serving Eagle Butte

System Name PWSID Population Source
TRI-COUNTY RURAL WATER SYSTEM SD4600112 2,190 SW
Regional Comparison

How Eagle Butte compares

Full South Dakota rankings →

Eagle Butte's score of 86.2/100 is above the average of 66/100 among major South Dakota cities. It outscores 6 of 10 nearby cities.

Eagle Butte (this city)
86.2
Rapid City
38.7
Aberdeen
41.8
Pierre
87.3
South Dakota avg
66
City Profile

About Eagle Butte, SD

Wikipedia →

Eagle Butte is a city in Dewey and Ziebach counties in South Dakota, United States. The population was 1,258 at the 2020 census. It is adjacent to the North Eagle Butte CDP.

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Frequently asked questions

Is Eagle Butte, SD tap water safe to drink?

Eagle Butte's water quality earned a grade of A- (86.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #67 out of 141 cities tested in South Dakota.

What contaminants are in Eagle Butte's water?

Lead was measured at 4.0 ppb (90th percentile). 1 PFAS compound was detected. 67 violations are on record.

How is Eagle Butte'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 Eagle Butte?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Eagle Butte's water come from?

Eagle Butte's water is sourced from Surface water. The city has 1 water system serving approximately 2,190 residents.

What health violations has Eagle Butte's water system had?

Eagle Butte has 15 health-based violations on record. The most recent violation was recorded in December 2022. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 8 violations remain unresolved.

How does Eagle Butte's water compare to other cities?

Eagle Butte ranks #67 out of 141 cities in South Dakota (better than 52% of state cities) and #4857 out of 15744 cities nationally (69th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Eagle Butte's small water system affect quality?

Eagle Butte's system serves approximately 2,190 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 67 violations on record.