OK / Hollis
OK · Tap water records
Hollis tap water, in plain English
Here is what the EPA's own data shows about tap water in Hollis. According to EPA SDWIS data retrieved June 2026, Hollis is served by 3 active community water systems, together reported to serve about 2,533 people.
As of June 2026, EPA records show 318 violations across the community water system(s) serving Hollis, going back to the earliest EPA record. 179 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
Hollis
2,264 served · groundwater · PWSID OK2002901 - Health-based Nitrate-Nitrite: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 68 times between January 2003 and July 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 33 times between August 1993 and April 2003. The EPA record lists a level of 12.43 ; the limit (MCL) is 10 . 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 3 times between August 1991 and May 1998. 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 3 ; the limit (MCL) is 0 . 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 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 4 times in October 2022. 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 October 2022. 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 2 times in January 2016. EPA records do not show all of these as returned to compliance.
- Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 48 times between December 1979 and March 1990. All have since returned to compliance, per EPA records.
Harmon Electric
188 served · groundwater · PWSID OK3002801 - Health-based Coliform (Pre-TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in April 1986. The EPA record lists a level of 8 ; the limit (MCL) is 0 . 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 once in September 2017. 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 once in September 2017. 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 July 2010. 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 March 1998. 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 11 times between October 1979 and July 1984. All have since returned to compliance, per EPA records.
Thirsty Water Corp
81 served · groundwater · PWSID OK2002806 - Health-based Nitrate-Nitrite: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 73 times between January 2010 and October 2025. The EPA record lists a level of 11 MG/L; the limit (MCL) is 10 MG/L. 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 14 times between January 2024 and October 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 14 times between January 2024 and October 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate-Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in April 2024. 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 September 2021 and September 2022. 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 10 times between July 2021 and July 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 2 times between June 1993 and July 2016. All have since returned to compliance, per EPA records.
- 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 once in July 2016. All have since returned to compliance, per EPA records.
- Monitoring Combined Uranium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2016. All have since returned to compliance, per EPA records.
- 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 once in July 2016. All have since returned to compliance, per EPA records.
- Monitoring Gross Beta Particle Activity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2016. 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 4 times between July 2006 and July 2013. 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 July 1998. 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 October 1979 and February 1983. 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.