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EPA SDWIS ~155K water systems EPA + UCMR5

Barium

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: 1010

Total Violations
50,993
Systems Affected
13,488
Health-Based %
3.2%
Most Affected State
-

What this means

Barium appears in EPA SDWIS with 50,993 recorded violations across 13,488 public water systems. Of those, 3.2% 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

Barium violations broken down by EPA classification.

Health-based (3.2%) Monitoring/Reporting (96.8%)

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
Marshall Water Works IN 479 330
Seaton IL 116 214
Ridgefield Public Works WA 114 20,967
Pasarella Pizzeria Inc NY 82 25
Hampshire IL 79 7,758
PA American Audubon PA 77 8,200
Seven Estates TX 67 189
Fitzgerald GA 65 15,382
Coal Mountain Water WV 56 80
Mount Eagle Water Assoc PA 55 130
Franklin Water Systems 3 TX 51 201
Hiawatha Water WV 51 63
Bartlett IL 49 41,500
Nottingham Manor M H Court PA 49 473
Washington Township Mua NJ 48 48,000
Shrewsbury Borough PA 48 4,727
Akhiok AK 42 90
Culvers Hill - North Webster IN 40 75
Westwood MHP NC 40 56
Pinnacle Water Association WV 40 85
Shiloh S/D NC 39 67
Whispering Pines MHP NC 39 305
Toxaway Point NC 38 79
Happy Camper RV Park CO 37 40
Glen Campbell Water Works PA 37 260
South Bend Water Department WA 37 2,930
Creekside South Estates Metro District CO 36 160
Burlington City Of CO 36 3,720
Windmill Estates IL 36 65
Carmel Montessori Academy IL 36 40

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 Barium in drinking water? ▼
Barium is a contaminant tracked by the EPA under the Safe Drinking Water Act. It has caused 50,993 violations across 13,488 public water systems nationwide. 3.2% of these violations are health-based, meaning the contaminant exceeded Maximum Contaminant Levels (MCLs) or treatment technique requirements.
How many water systems have Barium violations? ▼
13,488 public water systems across the United States have at least one Barium violation recorded in the EPA SDWIS database.
Are Barium violations dangerous? ▼
3.2% of Barium 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 Barium 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.