MO / Hannibal
MO · Tap water records
Hannibal tap water, in plain English
Here is what the EPA's own data shows about tap water in Hannibal. According to EPA SDWIS data retrieved June 2026, Hannibal is served by 2 active community water systems, together reported to serve about 24,770 people.
As of June 2026, EPA records show 61 violations across the community water system(s) serving Hannibal, going back to the earliest EPA record. 47 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.
What the EPA has on record, by system
Hannibal Pws
17,108 served · surface water · PWSID MO2010344 - Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in August 2023. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Health-based Long Term 2 Enhanced Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2016. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in May 2016. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based contaminant code null: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in May 2016. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 14 times between July 2011 and July 2015. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between November 2017 and March 2018. All have since returned to compliance, per EPA records.
- Monitoring Long Term 2 Enhanced Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between April 2016 and November 2016. All have since returned to compliance, per EPA records.
- Monitoring Cryptosporidium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in May 2016. All have since returned to compliance, per EPA records.
- Monitoring contaminant code null: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in May 2016. 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 once in September 2013. All have since returned to compliance, per EPA records.
Ralls County Pwsd 1
7,662 served · groundwater · PWSID MO2024499 - Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 28 times between January 2017 and January 2023. The EPA record lists a level of 84 UG/L; the limit (MCL) is 80 UG/L. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2017. 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.