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EPA SDWIS ~155K water systems EPA + UCMR5

Nitrate

EPA SDWIS quarterly extract data for this analyte. Detection counts and health-based violation counts reflect the most recent federal release.

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EPA contaminant code: 1040

Total Violations
490,545
Systems Affected
60,497
Health-Based %
16.4%
Most Affected State
-

What this means

Nitrate appears in EPA SDWIS with 490,545 recorded violations across 60,497 public water systems. Of those, 16.4% are classified as health-based, meaning the reading exceeded a federally enforceable Maximum Contaminant Level or a treatment-technique requirement rather than a monitoring or reporting lapse. Health-based violations are the subset that trigger formal corrective action and public notification, so the share is a useful signal of real-world exposure risk rather than paperwork drift. State-level concentration data is not consistently reported for this contaminant, so regional interpretation should lean on the system table below rather than state aggregates. Utilities listed below are ranked by cumulative violation count, so a higher rank reflects persistence in the record rather than a single spike; readers comparing systems should consider population served alongside violation count to gauge how many households were actually exposed.

Violation Type Split

Nitrate violations broken down by EPA classification.

Health-based (16.4%) Monitoring/Reporting (83.6%)

Health-based violations indicate the contaminant exceeded an EPA Maximum Contaminant Level (MCL) or treatment-technique requirement; monitoring/reporting violations are procedural.

Most Affected Water Systems

System State Violations Population
Burlington City Of CO 915 3,720
Franklin Water Systems 3 TX 783 201
Franklin Water Systems 3 TX 629 201
Seven Estates TX 621 189
Pretty Prairie, City Of KS 596 655
Welch WSC TX 591 315
Northgate Mobile Home Park 1 TX 588 126
Rra Hinds Wildcat Water System TX 586 228
Eola WSC TX 579 165
Rra Guthrie Dumont Water System TX 527 291
City of Quitaque TX 502 342
Turkey Municipal Water System TX 496 317
Rra Truscott Gilliland Water System TX 451 243
Whitharral WSC TX 443 200
Twin Oaks MHP Midland TX 437 234
Lazy Palms Ranch TX 426 400
City of Roscoe TX 423 1,238
Lubbock RV Park TX 422 150
City of Dodson TX 411 93
Northside WSC TX 394 250
Grassland WSC TX 393 55
Encinal RD WS #01 CA 345 91
Norwich, City Of KS 334 433
Greenwood Terrace M H Subdivision TX 332 120
Grady Isd TX 326 292
Hollis OK 323 2,264
City of Weinert TX 306 162
North Blaine Water Corp OK 300 960
Rra Lockett Water System TX 278 705
Cliffs Place Inc IA 275 51

Drinking Water Guides

Understanding Water Quality Data

What EPA SDWIS tracks, how violations are classified, and what MCLs mean.
PFAS in Drinking Water

What forever chemicals are, EPA testing results, and 2024 standards.
Is My Water Safe?

How to assess your local water quality and when to take precautions.

Frequently Asked Questions

What is Nitrate in drinking water? ▼
Nitrate is a contaminant tracked by the EPA under the Safe Drinking Water Act. It has caused 490,545 violations across 60,497 public water systems nationwide. 16.4% of these violations are health-based, meaning the contaminant exceeded Maximum Contaminant Levels (MCLs) or treatment technique requirements.
How many water systems have Nitrate violations? ▼
60,497 public water systems across the United States have at least one Nitrate violation recorded in the EPA SDWIS database.
Are Nitrate violations dangerous? ▼
16.4% of Nitrate violations are health-based, meaning the contaminant level exceeded safe limits set by the EPA. Health-based violations require corrective action by the water system. Not all violations indicate immediate health risk, but they signal that water quality standards were not met.
Which state has the most Nitrate violations? ▼
State-level breakdown data is not available for this contaminant.
Where does this contaminant data come from? ▼
All violation data comes from the EPA Safe Drinking Water Information System (SDWIS), which tracks compliance for all public water systems regulated under the Safe Drinking Water Act. SDWIS records violations including Maximum Contaminant Level (MCL) exceedances, treatment technique failures, and monitoring/reporting issues.

Data Sources

Contaminant violation data from the EPA Safe Drinking Water Information System (SDWIS). Violations are categorized as health-based (Maximum Contaminant Level exceedances, treatment technique failures) or monitoring/reporting violations.

Related

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Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the EPA Safe Drinking Water Information System (SDWIS). Consult a qualified professional before making decisions based on this data.

Read our methodology - how this data is sourced, computed, and verified.

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.