Here is what the EPA's own data shows about tap water in Casa Grande. According to EPA SDWIS data retrieved October 2026, Casa Grande is served by 2 active community water systems, together reported to serve about 1,271 people.
As of October 2026, EPA records show 77 violations across the community water system(s) serving Casa Grande, going back to the earliest EPA record. 37 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.
Health-based Nitrate: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 17 times between April 2013 and July 2017. 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.
Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 2017. The EPA record for these does not include a measured level. 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 9 times between October 2002 and January 2026. 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 October 2015 and March 2025. 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 7 times between July 2002 and July 2024. 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 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 once in January 2023. 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 once in May 2018. 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 November 2015. All have since returned to compliance, per EPA records.
Sierra Vista Rv Park
200 served · groundwater · PWSID AZ0411383
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 16 times between January 2020 and April 2024. The EPA record lists a level of 16 UG/L; the limit (MCL) is 10 UG/L. All have since returned to compliance, per EPA records.
Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in December 2023. 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 2 times between January 2016 and January 2017. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2020 and March 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 once in November 2023. 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 3 times between June 2019 and October 2020. 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 2020. 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 April 2019. 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 October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.