Pennington County Water Quality: 12 Violations (SD)
25 water systems · 17 ZIP codes · Grade C · Updated 2026-06-04
Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO Last verified: 2026-06-04
Violation Trend
EPA violations across water systems in Pennington County.
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Find the Right Filter →Water Quality Overview
Pennington County has 25 community water systems serving approximately 491,809 people across 17 ZIP codes. These systems have accumulated 12 EPA violations, including 7 health-based violations.
Health-based violations account for 58% of all violations in Pennington County. These violations indicate contaminant levels that may pose direct risks to human health.
Violation Breakdown
| Violation Type | Count | Percentage |
|---|---|---|
| Health-based | 7 | 58.3% |
| Monitoring/Reporting | 5 | 41.7% |
| Total | 12 | 100% |
Health-based violations indicate contaminant levels exceeding EPA Maximum Contaminant Levels (MCLs). Monitoring violations indicate failures to test or report.
Cities with Most Violations
| Rank | City | Violations | Health-Based | ZIP Codes | Population |
|---|---|---|---|---|---|
| 1 | Box Elder | 6 | 6 | 1 | 108,949 |
| 2 | New Underwood | 5 | 1 | 1 | 2,585 |
| 3 | Hill City | 1 | 0 | 1 | 1,544 |
Violation Trend
Year-by-year EPA violations across water systems in Pennington County:
| Year | Total | Health-Based |
|---|---|---|
| 2021 | 4 | 4 |
| 2022 | 8 | 8 |
| 2023 | 1 | 1 |
| 2024 | 3 | 3 |
| 2025 | 4 | 4 |
Most Common Contaminants
| Contaminant | Category | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|
| Gross Beta | Radionuclides | 3 | 1 | Yes |
| Gross Alpha | Radionuclides | 3 | 1 | Yes |
| Revised Total Coliform Rule | Microbiological | 2 | 1 | No |
| Chlorine residual | Disinfectant | 1 | 1 | Yes |
Understanding Water Quality Scores
Each ZIP code in Pennington County receives a safety score from 0-100 based on EPA compliance data. Scores factor in the number and severity of violations, with health-based violations weighted more heavily than monitoring failures. Resolved violations (where the system returned to compliance) receive reduced weight in the scoring.
The county-level grade (C) represents the average across all 17 ZIP codes. Individual ZIP codes may vary significantly — a county with a B grade may contain both A-rated and D-rated areas.
Water Systems in Pennington County
Pennington County is served by 25 community water systems, averaging 1.5 systems per ZIP code. Each system is independently regulated and tested by the EPA. Larger systems serving more people typically have more extensive monitoring requirements.
Water systems in Pennington County source water from a mix of surface water (rivers, reservoirs) and groundwater (wells, aquifers). Source type affects which contaminants are most likely to be detected.
How to Check Your Water in Pennington County
Enter your ZIP code on ZipCheckup for detailed water system data including contaminant levels, violation history, and safety scores
Request your CCR — every water utility must provide an annual Consumer Confidence Report
Get a home test — certified kits ($20-$50) or professional lab tests ($150-$400) can detect contaminants not covered by routine testing
Consider filtration — NSF-certified filters can address specific contaminants found in your area
Check for lead — homes built before 1986 should test for lead regardless of utility compliance
EPA Enforcement
The EPA and state regulators have taken 50 enforcement actions against water systems in Pennington County. Enforcement actions range from compliance assistance and administrative orders to formal penalties. Systems under enforcement are required to remediate violations and may face ongoing monitoring requirements.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Enforcement: EPA ECHO
Updated daily.
Water Quality Map: Pennington County, SD
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Pennington County
Water quality varies across Pennington County's 17 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | City | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|---|
| 57719 | Box Elder | C | 66 | 6 | 6 | View → |
| 57761 | New Underwood | B | 82 | 5 | 1 | View → |
| 57745 | Hill City | B | 83 | 1 | 0 | View → |
| 57751 | Keystone | B | 83 | 0 | 0 | View → |
| 57767 | Owanka | B | 83 | 0 | 0 | View → |
| 57790 | Wall | B | 83 | 0 | 0 | View → |
| 57709 | Rapid City | B | 80 | 0 | 0 | View → |
| 57701 | Rapid City | B | 76 | 0 | 0 | View → |
| 57702 | Rapid City | B | 76 | 0 | 0 | View → |
| 57703 | Rapid City | B | 76 | 0 | 0 | View → |
| 57759 | Nemo | C | 63 | 0 | 0 | View → |
| 57725 | Caputa | D | 53 | 0 | 0 | View → |
| 57737 | Enning | D | 53 | 0 | 0 | View → |
| 57750 | Interior | D | 53 | 0 | 0 | View → |
| 57775 | Quinn | D | 53 | 0 | 0 | View → |
| 57780 | Scenic | D | 53 | 0 | 0 | View → |
| 57792 | White Owl | D | 53 | 0 | 0 | View → |
What are EPA health violations?
Health-based violations mean a contaminant was detected above the EPA's Maximum Contaminant Level (MCL) — the legal limit designed to protect human health. Pennington County has 7 such violations. Not all violations cause illness, but repeated exceedances increase risk, especially for children and immunocompromised individuals.
What is a water quality grade?
ZipCheckup grades water systems from A to F based on EPA violation history, contaminant levels, and system compliance. Grade A means few or no violations; Grade F indicates persistent or serious issues. Pennington County's overall grade is C.
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Find the Right Filter →Frequently Asked Questions
Is the tap water safe in Pennington County, South Dakota?
Pennington County has 25 community water systems with 12 recorded EPA violations, including 7 health-based. Water quality varies by ZIP code — check your specific location for detailed results.
How many water violations does Pennington County have?
Pennington County has 12 total EPA violations across 17 ZIP codes. 7 are health-based violations indicating contaminant levels potentially harmful to health.
Which city in Pennington County has the most water violations?
Box Elder has the most violations in Pennington County with 6 recorded EPA violations across 1 ZIP codes.
What contaminants are found in Pennington County water?
Pennington County water systems are monitored for over 90 EPA-regulated contaminants including lead, copper, nitrates, disinfection byproducts, and bacteria. Check your ZIP code for contaminant-specific data.
How can I test my water in Pennington County?
Contact your local water utility for free or low-cost testing. You can also use a certified home test kit ($20-$50) or hire a certified lab ($150-$400).