OK / Hennessey
OK · Tap water records
Hennessey tap water, in plain English
Here is what the EPA's own data shows about tap water in Hennessey. According to EPA SDWIS data retrieved June 2026, Hennessey is served by 1 active community water system, together reported to serve about 2,058 people.
As of June 2026, EPA records show 68 violations across the community water system(s) serving Hennessey, going back to the earliest EPA record. 11 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
Hennessey
2,058 served · groundwater · PWSID OK2003704 - Health-based Nitrate-Nitrite: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between January 2014 and January 2022. The EPA record lists a level of 12 MG/L; the limit (MCL) is 10 MG/L. All have since returned to compliance, per EPA records.
- Health-based Coliform (TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times between December 1991 and June 1996. The EPA record lists a level of 0 ; the limit (MCL) is 0 . All have since returned to compliance, per EPA records.
- Health-based Coliform (Pre-TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between September 1986 and August 1990. The EPA record lists a level of 3 ; the limit (MCL) is 0 . All have since returned to compliance, per EPA records.
- Monitoring Orthophosphate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 17 times between July 2021 and January 2022. EPA records do not show all of these as returned to compliance.
- Monitoring CONDUCTIVITY @ 25 C UMHOS/CM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2022. EPA records do not show all of these as returned to compliance.
- Monitoring pH: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Alkalinity, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Temperature (Centigrade): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2022. EPA records do not show all of these as returned to compliance.
- Monitoring CALCIUM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate-Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2017 and October 2019. All have since returned to compliance, per EPA records.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between October 2017 and January 2019. 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 once in October 2018. 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 once in November 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 once in July 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 8 times between February 1995 and September 1998. All have since returned to compliance, per EPA records.
- Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 1979 and February 1987. 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.