Aldicarb Sulfoxide in drinking water
347 active public water systems in 11 states had a Aldicarb Sulfoxide violation in the past three years, and 10 have one that is still unresolved.
You are on Tapcensus, an independent guide to the EPA compliance records of every public water system in the United States. This page explains Aldicarb Sulfoxide and lists the water systems whose records include a related violation. It does not show measured levels.
Is Aldicarb Sulfoxide in the records for your water system?
Enter a ZIP code, town, or street address to see the water systems that serve your area, their status, and which rules and contaminants appear in their violations.
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What it is and where it comes from
Aldicarb sulfoxide is the primary oxidation metabolite of aldicarb, a carbamate insecticide and nematicide. It forms in soil and groundwater as aldicarb degrades and retains the same mechanism of toxicity. Aldicarb use was phased out and its EPA registration canceled in 2011, but legacy contamination persists at historically treated agricultural sites.
Health effects
Like its parent compound aldicarb, aldicarb sulfoxide inhibits acetylcholinesterase, disrupting nerve signal transmission. Acute exposure causes cholinergic symptoms: headache, blurred vision, nausea, muscle weakness, and in severe cases, respiratory distress. Children are most vulnerable to acute neurological effects from carbamate exposure.
The standard and what a violation means
EPA limit: 0.004 mg/L (4 ppb).
Water systems with a Aldicarb Sulfoxide violation, by state
Active public water systems that reported at least one related violation to EPA in the past three years. Each state links to the list of its affected systems.
| State | Systems with violations, 3 yr | Share of active systems | Unresolved |
|---|---|---|---|
| New York | 119 | 1% | 1 |
| Texas | 102 | 1% | 0 |
| Connecticut | 35 | 1% | 1 |
| Michigan | 26 | 0% | 0 |
| Colorado | 21 | 1% | 1 |
| Missouri | 16 | 1% | 1 |
| Rhode Island | 10 | 2% | 0 |
| Illinois | 9 | 0% | 4 |
| New Jersey | 6 | 0% | 2 |
| Wisconsin | 2 | 0% | 0 |
| Kentucky | 1 | 0% | 0 |
Largest water systems with a Aldicarb Sulfoxide violation
The ten biggest systems, by people served, whose records include a related violation in the past three years.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Denver Water Board Denver County |
1,287,000 | 3 | 0 | |
|
Aqua WSC Bastrop County |
86,325 | 5 | 1 | |
|
South Huntington Water District Huntington (t) · Suffolk County |
81,760 | 1 | 0 | |
|
Johnson County SUD Johnson County |
65,517 | 2 | 0 | |
|
Kiryas Joel Kiryas Joel (v) · Orange County |
51,623 | 3 | 0 | |
|
Clwsc Canyon Lake Shores Comal County |
44,196 | 6 | 0 | |
|
City of Sherman Grayson County |
43,645 | 2 | 0 | |
|
Clifton Park Water Authority Clifton Park (t) · Saratoga County |
35,000 | 6 | 1 | |
|
Bethesda WSC Johnson County |
33,441 | 2 | 0 | |
|
West Bend Waterworks West Bend · Washington County |
32,149 | 5 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Aldicarb Sulfoxide, including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not Aldicarb Sulfoxide alone. Counts cover active systems in all 50 states and the District of Columbia.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.