AZ / San Tan Valley
AZ · Tap water records
San Tan Valley tap water, in plain English
Here is what the EPA's own data shows about tap water in San Tan Valley. According to EPA SDWIS data retrieved June 2026, San Tan Valley is served by 4 active community water systems, together reported to serve about 98,772 people.
As of June 2026, EPA records show 338 violations across the community water system(s) serving San Tan Valley, going back to the earliest EPA record. 17 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
Epcor - San Tan
87,435 served · groundwater · PWSID AZ0411128 - Health-based Nitrate: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between January 2016 and January 2017. The EPA record lists a level of 12 MG/L; the limit (MCL) is 10 MG/L. 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 17 times between October 2015 and December 2024. 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 23 times between January 2018 and January 2024. All have since returned to compliance, per EPA records.
- Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. All have since returned to compliance, per EPA records.
- Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. 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 July 2015 and October 2020. 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 3 times between June 2017 and December 2018. 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 3 times between June 2017 and December 2018. 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 October 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 5 times between July 2002 and July 2007. 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 2002. All have since returned to compliance, per EPA records.
Epcor - San Tan Anthem
10,362 served · groundwater · PWSID AZ0411136 - Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 18 times between October 2015 and October 2024. 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 2 times in January 2023. EPA records do not show all of these as returned to compliance.
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in March 2022. All have since returned to compliance, per EPA records.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2016 and January 2021. 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 4 times between May 2018 and May 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 4 times between May 2018 and May 2019. 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 3 times between July 2008 and November 2017. All have since returned to compliance, per EPA records.
Sun Valley Farms Unit Vi
600 served · groundwater · PWSID AZ0411111 - Health-based Groundwater Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in November 2020. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based Nitrate: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 7 times between April 2015 and April 2018. The EPA record lists a level of 14 MG/L; the limit (MCL) is 10 MG/L. 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 22 times between July 2002 and October 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 9 times between August 2016 and October 2025. 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 between October 2022 and October 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 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 2 times in July 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 11 times between April 2016 and March 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2022 and November 2023. 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 8 times between September 2018 and September 2021. 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 7 times between September 2020 and September 2021. EPA records do not show all of these as returned to compliance.
- Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in May 2011. All have since returned to compliance, per EPA records.
Skyline Resort Rv Park
375 served · groundwater · PWSID AZ0411556 - Health-based Groundwater Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times 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 Nitrate: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between January 2018 and January 2020. The EPA record lists a level of 11 MG/L; the limit (MCL) is 10 MG/L. 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 19 times between July 2008 and October 2025. All have since returned to compliance, per EPA records.
- 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 July 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 26 times between July 2016 and February 2024. 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 4 times between October 2016 and January 2024. All have since returned to compliance, per EPA records.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between June 2018 and July 2019. All have since returned to compliance, per EPA records.
- Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2013 and January 2019. All have since returned to compliance, per EPA records.
- Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2013 and January 2019. All have since returned to compliance, per EPA records.
- Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2013 and January 2019. All have since returned to compliance, per EPA records.
- Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2013 and January 2019. All have since returned to compliance, per EPA records.
- Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2013 and January 2019. All have since returned to compliance, per EPA records.
- Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2013 and January 2019. 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 3 times between April 2017 and October 2018. All have since returned to compliance, per EPA records.
- Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2013 and July 2017. 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 2013 and June 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- 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 2014. All have since returned to compliance, per EPA records.
- Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. All have since returned to compliance, per EPA records.
- Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Diquat: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Endothall: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Glyphosate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring 2,3,7,8-TCDD: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. 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 once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Aroclor 1016: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Aroclor 1221: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Aroclor 1232: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Aroclor 1242: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Aroclor 1248: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Aroclor 1254: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Aroclor 1260: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- 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 once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring ETHYLENE DIBROMIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. All have since returned to compliance, per EPA records.
- Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2013. 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.