CA / Rancho Mission Viejo
CA · Tap water records
Rancho Mission Viejo tap water, in plain English
Here is what the EPA's own data shows about tap water in Rancho Mission Viejo. According to EPA SDWIS data retrieved June 2026, Rancho Mission Viejo is served by 1 active community water system, together reported to serve about 210 people.
As of June 2026, EPA records show 14 violations across the community water system(s) serving Rancho Mission Viejo, going back to the earliest EPA record. 3 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
Rancho Carrillo Mwc
210 served · groundwater · PWSID CA3301535 - Health-based Nitrate: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times between January 2017 and July 2017. The EPA record lists a level of 11.7 MG/L; the limit (MCL) is 10 MG/L. All have since returned to compliance, per EPA records.
- Monitoring Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2019. 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 between January 2016 and July 2018. All have since returned to compliance, per EPA records.
- Monitoring Aluminum: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2014. 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 4 times between July 2004 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 3 times between June 1999 and November 2001. 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.