OK / Nichols Hills
OK · Tap water records
Nichols Hills tap water, in plain English
Here is what the EPA's own data shows about tap water in Nichols Hills. According to EPA SDWIS data retrieved June 2026, Nichols Hills is served by 1 active community water system, together reported to serve about 4,020 people.
As of June 2026, EPA records show 254 violations across the community water system(s) serving Nichols Hills, going back to the earliest EPA record. 13 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
Nichols Hills
4,020 served · groundwater · PWSID OK2005501 - 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 Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between January 2016 and April 2016. The EPA record lists a level of 0.013 MG/L; the limit (MCL) is 0.01 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 6 times between November 1991 and August 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 Gross Alpha, Excl. Radon and U: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 1990. The EPA record lists a level of 45 ; the limit (MCL) is 15 . 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 2 times between January 1987 and October 1988. The EPA record lists a level of 1 ; the limit (MCL) is 0 . All have since returned to compliance, per EPA records.
- Health-based Selenium: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in May 1979. The EPA record lists a level of 0.04 ; the limit (MCL) is 0.01 . 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 6 times between January 2024 and January 2025. 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 6 times between January 2024 and January 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 Nitrate-Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 11 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Diquat: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Endothall: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Glyphosate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Total Polychlorinated Biphenyls (PCB): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2-DIBROMO-3-CHLOROPROPANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring ETHYLENE DIBROMIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2023 and January 2024. 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 2 times in October 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 4 times in October 2021. 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 June 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 2 times between March 1991 and October 1996. 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 5 times between May 1981 and April 1990. 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.