EPA SDWIS ~155K water systems EPA + UCMR5

Diquat

Compiled by PlainWater Editorial, Drinking Water Quality Editorial Team · May 15, 2026

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: 2032

Total Violations

29,815

Systems Affected

5,771

Health-Based %

Most Affected State

What this means

Diquat appears in EPA SDWIS with 29,815 recorded violations across 5,771 public water systems. Of those, 0% 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

Diquat violations broken down by EPA classification.

Health-based (0%) Monitoring/Reporting (100%)

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
Salem Heights Estate	PA	157	62
Congregation Ohr Menachem	PA	149	30
Skyview Estates	IL	124	56
Prague	OK	111	2,395
27 Maple Drive	CT	88	38
Aqua PA Sun Valley	PA	79	120
Neshaminy Manor Center	PA	74	2,100
Oilton	OK	64	1,435
Ambler Boro Water Dept	PA	60	20,000
Paradise Stream Resor	PA	60	774
Criswell Court MHP	IL	59	94
Willow Springs MHP	IN	56	25
Payson Town Of	AZ	55	17,682
Plymouth Community Church	IN	53	90
Indian Creek Valley Water Auth	PA	53	7,000
Pbc Linear	IL	52	140
Tower Springs LLC	PA	50	25
Boley Tool and Machine Works	IL	49	100
Southbrook Estates	SD	49	28
Santiam Meadows Community WS	OR	46	40
Creekside South Estates Metro District	CO	45	160
Virgin Valley Water District	NV	45	26,000
Bridge Creek School	OK	45	800
Roamingwood Sewer and Water	PA	45	3,775
Bermuda Water Company Inc	AZ	44	25,000
Joseph Harp Corr Inst	OK	44	3,000
Rock Creek	OK	44	33
PA American Audubon	PA	44	8,200
Happy Camper RV Park	CO	43	40
Save a Pet	IL	43	50

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 Diquat in drinking water? ▼

Diquat is a contaminant tracked by the EPA under the Safe Drinking Water Act. It has caused 29,815 violations across 5,771 public water systems nationwide. 0% of these violations are health-based, meaning the contaminant exceeded Maximum Contaminant Levels (MCLs) or treatment technique requirements.

How many water systems have Diquat violations? ▼

5,771 public water systems across the United States have at least one Diquat violation recorded in the EPA SDWIS database.

Are Diquat violations dangerous? ▼

0% of Diquat 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 Diquat 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.

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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.