OK / Cheyenne
OK · Tap water records
Cheyenne tap water, in plain English
Here is what the EPA's own data shows about tap water in Cheyenne. According to EPA SDWIS data retrieved June 2026, Cheyenne is served by 2 active community water systems, together reported to serve about 978 people.
As of June 2026, EPA records show 221 violations across the community water system(s) serving Cheyenne, going back to the earliest EPA record. 50 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
Cheyenne
778 served · surface water · PWSID OK1010803 - Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 39 times between July 2012 and July 2025. The EPA record lists a level of 0.086 MG/L; the limit (MCL) is 0.08 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 Interim Enhanced Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2018. 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 October 2018. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based Turbidity: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between December 1984 and December 1990. The EPA record lists a level of 1.6 ; the limit (MCL) is 1 . All have since returned to compliance, per EPA records.
- Monitoring CARBON, TOTAL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 20 times between October 2016 and November 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 7 times between May 2023 and November 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 4 times between January 2024 and November 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 5 times between May 2023 and December 2024. EPA records do not show all of these as returned to compliance.
- 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 Sodium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2024. 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 4 times in May 2023. EPA records do not show all of these as returned to compliance.
- Monitoring Coliform (TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2015. 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 2 times between July 2012 and July 2013. 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 21 times between July 1980 and December 1988. 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 December 1982 and July 1988. All have since returned to compliance, per EPA records.
Roger Mills Rws & Swmd #1
200 served · groundwater · PWSID OK2006502 - 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 Coliform (Pre-TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 5 times between April 1981 and October 1987. The EPA record lists a level of 80 ; the limit (MCL) is 0 . 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 2 times between October 2024 and September 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 18 times between April 2019 and September 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 11 times between June 2019 and September 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 3 times between June 1993 and July 2025. EPA records do not show all of these as returned to compliance.
- 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 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 14 times between January 2023 and April 2024. 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 2 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 January 2023. EPA records do not show all of these as returned to compliance.
- Monitoring Gross Alpha, Excl. Radon and U: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between January 2017 and January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Combined Uranium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between January 2017 and January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Combined Radium (-226 and -228): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between January 2017 and January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Gross Beta Particle Activity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between January 2017 and January 2020. 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 3 times between July 2012 and July 2017. All have since returned to compliance, per EPA records.
- Monitoring Arsenic: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2011. EPA records do not show all of these as returned to compliance.
- Monitoring Coliform (TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between March 1996 and September 1997. 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 16 times between December 1979 and June 1986. 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.