Here is what the EPA's own data shows about tap water in Toppenish. According to EPA SDWIS data retrieved July 2026, Toppenish is served by 8 active community water systems, together reported to serve about 11,293 people.
As of July 2026, EPA records show 73 violations across the community water system(s) serving Toppenish, going back to the earliest EPA record. None were health-based; the records are monitoring or reporting violations (a required test or report was late or missed). Each is listed by system below, with its status.
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 between October 2024 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 2 times between October 2024 and July 2025. EPA records do not show all of these as returned to compliance.
Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times in January 2022. EPA records do not show all of these as returned to compliance.
Monitoring Chloromethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Bromomethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring o-Chlorotoluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring 1,1-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Bromobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. EPA records do not show all of these as returned to compliance.
Tribal Complex
907 served · groundwater · PWSID 105300025
As of July 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.
White Swan
900 served · groundwater · PWSID 105300026
As of July 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.
Parker
300 served · groundwater · PWSID 105338102
As of July 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.
Yakima Golding Farms 1
90 served · groundwater · PWSID WA5399110
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 August 2018 and October 2025. All have since returned to compliance, per EPA records.
Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 29 times between October 2016 and July 2025. 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 5 times between July 2013 and July 2023. 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 January 2019. 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 January 2019. All have since returned to compliance, per EPA records.
Georgeville
70 served · groundwater · PWSID 105300024
As of July 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.
B & D Mobile Court
45 served · groundwater · PWSID 105300073
As of July 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.
Mt Adams Country Club Estates
31 served · groundwater · PWSID WA5304694
As of July 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.
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 July 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.