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EPA SDWIS High-volume analyte Majority health-based Dense per-system load

Arsenic in Drinking Water

57.1% of 171,997 recorded violations are health-based - 16,264 systems in the EPA SDWIS extract.

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EPA contaminant code: 1005

Total Violations
171,997
Systems Affected
16,264
Health-Based %
57.1%
Violations / System
10.6

Arsenic standing, high-volume SDWIS third

Arsenic sits in the upper third of this extract by raw violation count (171,997), 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 is concentrated: 10.6 violations per affected system (dense load (> 5.8 violations per affected system)), which usually means repeat findings on the same PWSIDs rather than one-off detections spread thin. Health-based share is 57.1% - most of this analyte's ledger is MCL or treatment-technique exceedance, not paperwork. Among 157 indexable contaminants, this page is #11 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

Surface Water Treatment Rule (165,477) Combined Uranium (184,297) Chlorine (199,108) Combined Radium (-226 and -228) (142,845)

Nearest by systems affected

E. COLI (17,344 systems) Benzene (14,910 systems) Trichloroethylene (14,829 systems) Carbon tetrachloride (14,788 systems)

Arsenic: mostly health-based findings

57.1% health-based · 42.9% monitoring/reporting across 171,997 records.

Health-based (57.1%) Monitoring/Reporting (42.9%)

Most Affected Water Systems

System State Violations Population
Eakly Development Corp OK 1,062 277
City of Wolfforth TX 896 9,600
Tri County Sud TX 794 5,353
Bruni Rural WSC TX 689 350
Tempe WSC 1 TX 656 2,725
City of Seagraves TX 629 2,417
Duval County Crd Benavides TX 599 2,285
Gallery Acres West IA 584 43
Pb & SC Water Supply Corporation TX 573 2,163
Lynwood 3rd Addition IL 548 100
Stormlight Mobile Home Park TX 544 76
Eol WSC TX 533 2,195
City of Seminole TX 532 7,386
M S WSC TX 499 744
Ellinger Sewer and WSC TX 483 573
Leroy Tours Gerald WSC TX 480 1,680
Danvers IL 461 1,183
City of Smyer TX 450 474
Town North Village Water System TX 443 360
City of Plains TX 438 1,355
Hanford, City Of CA 413 62,127
Jim Hogg County Wcid 2 TX 410 5,397
Prairie Hill WSC TX 402 2,145
Axtell WSC TX 389 1,320
Welch WSC TX 378 315
City of Wellman TX 376 200
City of Riesel TX 365 1,476
Camino Real Regional Utility Authority NM 358 19,466
City of Andrews TX 358 14,109
Loma Escondida Water Association NM 351 89

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.