What is Barium in drinking water?

Barium has 50,993 recorded EPA SDWIS violations across 13,488 public water systems (upper-third volume (> 49,133 violations)).

How many water systems have Barium violations?

13,488 systems, a wide national footprint (wide footprint (> 8,691 systems)).

Are Barium violations dangerous?

3.2% are health-based. The rest are monitoring/reporting, still compliance failures, but not the same as an MCL exceedance.

Where does Barium sit in the national contaminant ledger?

#46 of 157 indexable contaminants by violation volume - upper-third volume (> 49,133 violations), mid load (≤ 5.8 violations per affected system).

Where does this contaminant data come from?

EPA Safe Drinking Water Information System (SDWIS) quarterly extracts. Counts are cumulative compliance records, not a live risk score for a single tap.

Contaminants →

EPA SDWIS High-volume analyte

Barium in Drinking Water

Compiled by PlainWater · May 15, 2026

13,488 public water systems carry at least one Barium violation - wide footprint (> 8,691 systems).

Browse all SDWIS contaminants →

EPA contaminant code: 1010

Total Violations

50,993

Systems Affected

13,488

Health-Based %

3.2%

Violations / System

3.8

Barium standing, high-volume SDWIS third

Barium sits in the upper third of this extract by raw violation count (50,993), so the national record is thick enough that system-level lists below are a sample of a much larger compliance trail rather than a near-complete inventory. Load sits mid-pack at 3.8 violations per affected system (mid load (≤ 5.8 violations per affected system)). Health-based share is only 3.2% - almost all of this analyte's trail is monitoring/reporting rather than MCL exceedance. Among 157 indexable contaminants, this page is #46 by violation volume. Utilities listed below are ranked by cumulative violation count for this analyte; pair that with population served to gauge household exposure scale.

Nationwide similar contaminants

Nearest by violation volume

BHC-GAMMA (50,797) Methoxychlor (50,526) Cadmium (50,411) Mercury (49,728)

Nearest by systems affected

Chromium (13,419 systems) Fluoride (13,411 systems) Selenium (13,645 systems) Nitrite (13,772 systems)

Barium: mixed health vs monitoring split

3.2% health-based · 96.8% monitoring/reporting across 50,993 records.

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

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

Context: understanding water quality data · is my water safe?

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

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.