OK / Grandfield
OK · Tap water records
Grandfield tap water, in plain English
Here is what the EPA's own data shows about tap water in Grandfield. According to EPA SDWIS data retrieved June 2026, Grandfield is served by 1 active community water system, together reported to serve about 1,110 people.
As of June 2026, EPA records show 286 violations across the community water system(s) serving Grandfield, going back to the earliest EPA record. 264 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
Grandfield
1,110 served · surface water · PWSID OK2007103 - Health-based Nitrate-Nitrite: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 141 times between January 2004 and October 2025. 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 114 times between October 2004 and January 2024. 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 Nitrate: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 8 times between December 1978 and January 1997. The EPA record lists a level of 11.752 ; the limit (MCL) is 0 . 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 June 1993. The EPA record lists a level of 0 ; the limit (MCL) is 0 . 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 TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 10 times between December 2022 and December 2023. All have since returned to compliance, per EPA records.
- Monitoring Stage 2 Disinfectants and Disinfection Byproducts Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2010. 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 October 2009. 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 2 times between July 2006 and October 2008. 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 January 1995 and November 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 3 times between December 1979 and May 1980. 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.