Tahlequah tap water, in plain English

• Health-based LEAD AND COPPER RULE REVISIONS: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
• Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 11 times between July 2017 and October 2022. The EPA record lists a level of 0.071 MG/L; the limit (MCL) is 0.06 MG/L. 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 10 times between January 2014 and October 2019. 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 TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 2017. The EPA record lists a level of 0.082 MG/L; the limit (MCL) is 0.08 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 5 times between October 1994 and December 1997. 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 once in January 1986. The EPA record lists a level of 8 ; the limit (MCL) is 0 . 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 October 2024. All have since returned to compliance, per EPA records.
• Monitoring Asbestos: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in January 2023. EPA records do not show all of these as returned to compliance.
• Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in June 2022. 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 once in August 2019. All have since returned to compliance, per EPA records.
• Monitoring 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 October 1999. All have since returned to compliance, per EPA records.
• Monitoring Turbidity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between October 1979 and March 1980. All have since returned to compliance, per EPA records.

• Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 19 times between July 2014 and October 2025. The EPA record lists a level of 0.07 MG/L; the limit (MCL) is 0.06 MG/L. EPA records do not show all of these as returned to compliance.
• Health-based LEAD AND COPPER RULE REVISIONS: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. 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 16 times between July 2014 and January 2023. The EPA record lists a level of 0.104 MG/L; the limit (MCL) is 0.08 MG/L. EPA records do not show all of these as returned to compliance.
• Health-based Coliform (TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 1998. The EPA record lists a level of 0 ; the limit (MCL) is 0 . 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 18 times between July 2010 and July 2025. 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 October 2024. 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 8 times between June 2022 and September 2023. EPA records do not show all of these as returned to compliance.
• Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 16 times between July 2015 and July 2023. EPA records do not show all of these as returned to compliance.
• Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between April 2015 and April 2023. All have since returned to compliance, per EPA records.
• Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between April 2015 and April 2023. 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 6 times between June 1993 and October 2021. 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 1997 and October 1998. 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 April 2017 and April 2019. 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 6 times between June 1993 and July 2001. 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 April 1998. All have since returned to compliance, per EPA records.

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.

• Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 9 times between July 2014 and April 2022. The EPA record lists a level of 0.082 MG/L; the limit (MCL) is 0.08 MG/L. EPA records do not show all of these as returned to compliance.
• Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between July 2011 and July 2025. EPA records do not show all of these as returned to compliance.
• Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times between October 2019 and 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 3 times between November 2019 and July 2025. EPA records do not show all of these as returned to compliance.
• Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 12 times between April 2015 and March 2024. All have since returned to compliance, per EPA records.
• Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between August 2021 and February 2022. 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 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 Coliform (TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 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.