WaterVerge

Is Ellsworth Afb, SD Tap Water Safe to Drink?

Graded A, with 2 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

9K residents served 1 water system PWSID: SD4680004
Overall Score
91.2 / 100
Violations
2 active
Last Updated
May 2026
Source
Purchased surface water
#31 of 141 in South Dakota Top 12% nationally
Federal
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
91.2/100
waterverge.com
A 91.2/100

Ellsworth Afb, SD — Water Quality Report

Ellsworth Afb's drinking water received a grade of A (91.2 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 9,100 residents using purchased surface water.

Lead levels were measured at 1.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 7 violations on record, including 4 health-based violations. 2 remain unresolved.

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

What to know about Ellsworth Afb's water

Ellsworth Afb ranks #31 out of 141 cities in South Dakota for water quality, placing it above 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.

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.

Quality Breakdown

Water quality score

See methodology →
91.2 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
44/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 1.0 ppb (90th percentile).
Contaminants
18.2/20
A
1 PFAS compound detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Purchased surface water.
Water Safety

Is Ellsworth Afb, SD water safe to drink?

Use Caution

Ellsworth Afb's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (91.2/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 9,100 residents using surface water (rivers, lakes, or reservoirs).

2
Active Violations
1.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected

Recent water quality updates for Ellsworth Afb

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 Ellsworth Afb's water quality assessment. Grade: A (91.2/100).

Violation
1 drinking water violation recorded

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

Violation
2 drinking water violations recorded

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

Violation
1 drinking water violation recorded

Key contaminant findings

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

Lead Within Limits
Detected: 1.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 9.9600 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

Ellsworth Afb's water system has 7 total violations on record, including 4 health-based violations. 2 remain unresolved.

MCLOtherMR
Most recent violations:
Oct 2014 Coliform (TCR) Resolved
Aug 2014 Coliform (TCR) Resolved
Aug 2014 Coliform (TCR) Resolved
Jun 2005 Coliform (TCR) Resolved

Where does Ellsworth Afb's water come from?

Ellsworth Afb's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 9,100 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.

What Ellsworth Afb residents can do

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
1.0 ppb
EPA Action Level: 15 ppb · 7% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
9.9600 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
Lithium
Inorganic
Detected
10.0 µg/L
State screening level: 60 µg/L · 17% of 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

7
Total violations
4
Health-based
2
Active / unresolved
Oct 2014
Most recent violation
Compliance Record

Violations & advisories

7 Total
2 Active
4 Health-based
5 Resolved
Violations by category
Total Coliform Rule
5
Ground Water Rule
1
Apr 2013 Active
Ground Water Rule
Other Violation 0
Active
Compliance Violation
Monitoring 0
Oct 2014 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Oct 2014
Aug 2014 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Aug 2014
Aug 2014 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Aug 2014
Jun 2005 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Jun 2005
Sep 1992 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 1992
Environmental Risk

Drought conditions

D3 — extreme drought

Pennington 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.

10
Weeks at D2+ (current streak)
23.7%
Months in D2+ (last 30y)
10
Weeks at D2+ (last 5y)

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

Recommended water filters

Based on contaminants detected in Ellsworth Afb'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) 1.0 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 9.960 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 decreased by 2.0 ppb from 1992 (3.0 ppb) to 2025 (1.0 ppb).
Contaminant Rankings

See how Ellsworth Afb compares by contaminant

Explore where Ellsworth Afb ranks among all South Dakota cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Purchased Surface Water
Operator
Federal
Population Served
9,100
Water Systems
1
Water Source

Where Ellsworth Afb's water comes from

Purchased Surface Water

Ellsworth Afb'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 federal ownership and serves approximately 9,100 people through 1 water system.

Infrastructure

Water systems serving Ellsworth Afb

System Name PWSID Population Source
ELLSWORTH AFB SD4680004 9,100 SWP
Regional Comparison

How Ellsworth Afb compares

Full South Dakota rankings →

Ellsworth Afb's score of 91.2/100 is above the average of 66/100 among major South Dakota cities. It outscores 9 of 10 nearby cities.

Ellsworth Afb (this city)
91.2
Rapid City
38.7
Aberdeen
41.8
Pierre
87.3
South Dakota avg
66
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Frequently asked questions

Is Ellsworth Afb, SD tap water safe to drink?

Ellsworth Afb's water quality earned a grade of A (91.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #31 out of 141 cities tested in South Dakota.

What contaminants are in Ellsworth Afb's water?

Lead was measured at 1.0 ppb (90th percentile). 1 PFAS compound was detected. 7 violations are on record.

How is Ellsworth Afb'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 Ellsworth Afb?

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

Where does Ellsworth Afb's water come from?

Ellsworth Afb's water is sourced from Purchased surface water. The city has 1 water system serving approximately 9,100 residents.

What health violations has Ellsworth Afb's water system had?

Ellsworth Afb has 4 health-based violations on record. The most recent violation was recorded in October 2014. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.

How does Ellsworth Afb's water compare to other cities?

Ellsworth Afb ranks #31 out of 141 cities in South Dakota (better than 78% of state cities) and #1800 out of 15744 cities nationally (89th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.