Here is what the EPA's own data shows about tap water in Blackwell. According to EPA SDWIS data retrieved October 2026, Blackwell is served by 3 active community water systems, together reported to serve about 8,590 people.
As of October 2026, EPA records show 73 violations across the community water system(s) serving Blackwell, going back to the earliest EPA record. 42 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.
Health-based Interim Enhanced Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 9 times between May 2019 and July 2025. 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 20 times between July 2014 and January 2023. The EPA record lists a level of 0.12 MG/L; the limit (MCL) is 0.08 MG/L. 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 September 2022. The EPA record for these does not include a measured level. 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 once in November 1995. 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 3 times between December 1981 and December 1983. The EPA record lists a level of 3 ; the limit (MCL) is 1 . All have since returned to compliance, per EPA records.
Monitoring Interim Enhanced Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in May 2025. All have since returned to compliance, per EPA records.
Monitoring Chlorine dioxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in May 2025. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between December 2016 and April 2025. All have since returned to compliance, per EPA records.
Monitoring Sodium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2024. All have since returned to compliance, per EPA records.
Monitoring Chlorite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between November 2019 and August 2020. 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 2 times between January 2018 and January 2020. 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 3 times between July 2012 and July 2017. 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 once in September 1991. 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 6 times between June 1980 and December 1989. All have since returned to compliance, per EPA records.
Kay County Rural Water District 7
920 served · surface water · PWSID OK3003601
Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 7 times between July 2014 and July 2023. The EPA record lists a level of 0.16 MG/L; the limit (MCL) is 0.08 MG/L. 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 once in May 1981. The EPA record lists a level of 2 ; the limit (MCL) is 1 . 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 2012. 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 2 times between August 1991 and July 1998. 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 June 1993. 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 May 1981. All have since returned to compliance, per EPA records.
Kay Electric Cooperative
2 served · groundwater · PWSID OK2003632
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 August 2020. 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 October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.