Does Chesterfield, MO tap water have any EPA-reported violations?

As of June 2026, EPA SDWIS records show 147 violation(s) across the community water systems serving Chesterfield, of which 38 are classified by the EPA as health-based. Most older violations have returned to compliance; see the per-system list.

Where does Chesterfield, MO tap water come from?

Chesterfield is served by 4 active community water system(s). Their primary sources, per EPA records, are: surface water, groundwater.

MO / Chesterfield

MO · Tap water records

Chesterfield tap water, in plain English

Here is what the EPA's own data shows about tap water in Chesterfield. According to EPA SDWIS data retrieved June 2026, Chesterfield is served by 4 active community water systems, together reported to serve about 1,113,079 people.

As of June 2026, EPA records show 147 violations across the community water system(s) serving Chesterfield, going back to the earliest EPA record. 38 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.

4

Community water systems
~1,113,079

People served (EPA-reported)
June 2026

EPA records reviewed through

What the EPA has on record, by system

Mo American St Louis St Charles Counties

1,111,000 served · surface water · PWSID MO6010716

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Mo American Ironton

1,460 served · surface water · PWSID MO4010402

Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 27 times between April 2016 and October 2025. The EPA record lists a level of 87 UG/L; the limit (MCL) is 80 UG/L. EPA records do not show all of these as returned to compliance.
Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times in January 2024. The EPA record lists a level of 61.45 UG/L; the limit (MCL) is 60 UG/L. EPA records do not show all of these as returned to compliance.
Health-based Stage 1 Disinfectants and Disinfection Byproducts Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in February 2022. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.

Mo American Pevely Farms

343 served · groundwater · PWSID MO6031185

Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2012 and July 2014. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2012. All have since returned to compliance, per EPA records.

Mo American Rogue Creek Utilities

276 served · groundwater · PWSID MO4036318

Health-based Groundwater Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 6 times between September 2013 and July 2016. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 57 times between March 2013 and April 2017. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 9 times between July 2016 and February 2017. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 12 times between July 2013 and July 2016. All have since returned to compliance, per EPA records.
Monitoring Groundwater Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in May 2016. All have since returned to compliance, per EPA records.
Monitoring Coliform (TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 12 times between October 2015 and February 2016. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in October 2015. All have since returned to compliance, per EPA records.
Monitoring Nitrate-Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2015. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between October 2011 and February 2012. All have since returned to compliance, per EPA records.

What this means

A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.

This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.

Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.