Pennsylvania Water Quality Report: 12,763 Violations Across 2,184 ZIPs
2,453 water systems · 2,184 ZIP codes · 12,763 violations · Updated 2026-05-31
Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO Last verified: 2026-05-31
City Water Quality Map: Pennsylvania
Each circle represents a city. Size indicates population, color indicates water quality grade. Tap a circle for details.
Violation Trend
EPA violations across all water systems in Pennsylvania.
Cities with Most Violations in Pennsylvania
| # | City | Grade | Violations | Systems | Population | |
|---|---|---|---|---|---|---|
| 1 | Pittsburgh | C | 847 | 5 | 782,354 | Details → |
| 2 | Erie | B | 672 | 5 | 234,035 | Details → |
| 3 | Harrisburg | C | 416 | 5 | 236,925 | Details → |
| 4 | Johnstown | B | 360 | 5 | 80,392 | Details → |
| 5 | Philadelphia | A | 348 | 1 | 1,600,000 | Details → |
| 6 | York | D | 198 | 5 | 221,854 | Details → |
| 7 | Lancaster | C | 168 | 5 | 120,720 | Details → |
| 8 | Allentown | D | 117 | 5 | 191,625 | Details → |
| 9 | Cyclone | F | 109 | 1 | 87 | Details → |
| 10 | Havertown | F | 99 | 2 | 275 | Details → |
Most Common Contaminants in Pennsylvania
| Contaminant | Category | Violations | ZIPs Affected | Health Risk |
|---|---|---|---|---|
| Contaminant 0700 | Other | 2,113 | 574 | Yes |
| Lead and Copper Rule | Treatment Technique | 1,250 | 442 | No |
| Revised Total Coliform Rule | Microbiological | 1,181 | 402 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 1,104 | 607 | Yes |
| Fecal Coliform | Microbiological | 1,039 | 343 | Yes |
| Surface Water Treatment Rule | Treatment Technique | 995 | 472 | No |
| E. coli | Microbiological | 675 | 321 | Yes |
| Chlorite | Disinfection Byproducts | 658 | 229 | Yes |
| Stage 1 DBP Rule | Treatment Technique | 311 | 233 | Yes |
| Copper | Inorganic | 243 | 168 | No |
Water Quality Overview
Pennsylvania has 2,453 community water systems serving approximately 83,155,005 people across 2,184 ZIP codes. These systems have accumulated 12,763 EPA violations, including 917 health-based violations.
Health-based violations account for 7% of all violations in Pennsylvania. These violations indicate contaminant levels that may pose direct risks to human health, as opposed to monitoring or reporting failures.
Violation Breakdown
| Violation Type | Count | Percentage |
|---|---|---|
| Health-based | 917 | 7.2% |
| Monitoring/Reporting | 11,846 | 92.8% |
| Total | 12,763 | 100% |
Health-based violations indicate contaminant levels exceeding EPA Maximum Contaminant Levels (MCLs). Monitoring violations indicate failures to test or report — these do not necessarily mean unsafe water, but they mean the water was not properly verified.
Cities with Most Violations
The following cities in Pennsylvania have the highest number of EPA violations:
| Rank | City | Grade | Violations | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Pittsburgh | C | 847 | 5 | 782,354 |
| 2 | Erie | B | 672 | 5 | 234,035 |
| 3 | Harrisburg | C | 416 | 5 | 236,925 |
| 4 | Johnstown | B | 360 | 5 | 80,392 |
| 5 | Philadelphia | A | 348 | 1 | 1,600,000 |
| 6 | York | D | 198 | 5 | 221,854 |
| 7 | Lancaster | C | 168 | 5 | 120,720 |
| 8 | Allentown | D | 117 | 5 | 191,625 |
| 9 | Cyclone | F | 109 | 1 | 87 |
| 10 | Havertown | F | 99 | 2 | 275 |
Violation counts are cumulative across all water systems serving each city. Higher counts may reflect larger systems with more monitoring requirements, not necessarily worse water quality.
Violation Trend Over Time
Year-by-year EPA violations recorded across all water systems in Pennsylvania:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 398 | 398 |
| 2022 | 696 | 696 |
| 2023 | 420 | 420 |
| 2024 | 823 | 823 |
| 2025 | 745 | 745 |
| 2026 | 27 | 27 |
Violations have decreased from 398 in 2021 to 27 in 2026, suggesting improving compliance across Pennsylvania.
Most Common Contaminants
The following contaminants have caused the most violations across Pennsylvania water systems:
| Contaminant | Category | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|
| Lead and Copper Rule | Treatment Technique | 1,250 | 442 | No |
| Revised Total Coliform Rule | Microbiological | 1,181 | 402 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 1,104 | 607 | Yes |
| Fecal Coliform | Microbiological | 1,039 | 343 | Yes |
| Surface Water Treatment Rule | Treatment Technique | 995 | 472 | No |
| E. coli | Microbiological | 675 | 321 | Yes |
| Chlorite | Disinfection Byproducts | 658 | 229 | Yes |
| Stage 1 DBP Rule | Treatment Technique | 311 | 233 | Yes |
| Copper | Inorganic | 243 | 168 | No |
| Total Organic Carbon | Disinfection Byproducts | 208 | 158 | No |
How to Check Your Water in Pennsylvania
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)
Consider filtration — NSF-certified filters can address specific contaminants found in your area
EPA Enforcement
The EPA and state regulators have taken 19,774 enforcement actions against water systems in Pennsylvania. Enforcement actions range from compliance assistance to formal orders and penalties.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Enforcement: EPA ECHO
Updated daily.
What are EPA 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. Pennsylvania has 917 such violations across its water systems. Not all violations cause illness, but repeated exceedances increase risk, especially for children and immunocompromised individuals.
Understanding water quality grades
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. Grades are calculated per ZIP code and aggregated at the city, county, and state level.
Wondering about your tap water?
Water quality varies by ZIP code. Enter yours to see contaminant data, violations, and filtration recommendations specific to your area.
Check Your ZIP Code Water Quality →Frequently Asked Questions
Is the tap water safe to drink in Pennsylvania?
Pennsylvania has 2,453 community water systems with 12,763 recorded EPA violations, including 917 health-based. Water quality varies by city and ZIP code — check your specific location for detailed results.
How many water violations does Pennsylvania have?
Pennsylvania has 12,763 total EPA violations across 2,184 ZIP codes. 917 are health-based violations that indicate contaminant levels potentially harmful to human health. The remainder are monitoring or reporting violations.
Which city in Pennsylvania has the worst water quality?
Pittsburgh, PA has the most EPA violations among major cities in Pennsylvania with 847 recorded violations. Check individual ZIP codes for the most accurate picture of your local water quality.
Which city in Pennsylvania has the best water quality?
Several cities in Pennsylvania maintain excellent EPA compliance. Check individual city reports for details.
What contaminants are found in Pennsylvania drinking water?
Pennsylvania water systems are monitored for over 90 EPA-regulated contaminants including lead, copper, nitrates, disinfection byproducts, and bacteria. The most common violations vary by region — check your ZIP code for contaminant-specific data.