Modesto, City Of
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.
CA / Modesto
CA · Tap water records
Modesto tap water, in plain English
Here is what the EPA's own data shows about tap water in Modesto. According to EPA SDWIS data retrieved July 2026, Modesto is served by 16 active community water systems, together reported to serve about 239,487 people.
As of July 2026, EPA records show 46 violations across the community water system(s) serving Modesto, going back to the earliest EPA record. 6 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.
- 16Community water systems
- ~239,487People served (EPA-reported)
- July 2026EPA records reviewed through
What the EPA has on record, by system
City Of Modesto - Salida
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in December 2012. 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 in June 1996. 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 3 times in May 1996. 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 3 times in November 1995. All have since returned to compliance, per EPA records.
- Monitoring Gross Alpha Particle Activity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in July 1995. 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 3 times in July 1995. All have since returned to compliance, per EPA records.
- Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 1995. All have since returned to compliance, per EPA records.
City Of Modesto - Del Rio
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.
City Of Modesto - South Turlock
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.
City Of Modesto - Grayson
- Health-based Nitrate: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times between April 1995 and July 1995. The EPA record lists a level of 45.85 MG/L; the limit (MCL) is 45 MG/L. All have since returned to compliance, per EPA records.
Hillsview Homes
- 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 in January 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 3 times between July 1999 and January 2016. All have since returned to compliance, per EPA records.
- Monitoring Gross Alpha Particle Activity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in June 1999. All have since returned to compliance, per EPA records.
Riverdale Park Tract Csd
- Health-based Combined Uranium: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times between January 2016 and October 2020. The EPA record lists a level of 22 PCI/L; the limit (MCL) is 20 PCI/L. EPA records do not show all of these as returned to compliance.
- Monitoring Combined Uranium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between April 2024 and July 2024. EPA records do not show all of these as returned to compliance.
Buena Vista Migrant Center
- 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 in April 2022. 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 January 2015. All have since returned to compliance, per EPA records.
Park Heights Mutual Water Co
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.
City Of Modesto - Walnut Manor
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.
City Of Modesto - North Turlock
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.
City Of Modesto - Central Turlock
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.
Morningside Mobilehome Park
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2007. All have since returned to compliance, per EPA records.
Country Western Mhrv
- 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 2022. EPA records do not show all of these as returned to compliance.
River Road Mutual Water Company
- 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 January 2025 and July 2025. EPA records do not show all of these as returned to compliance.
Modesto Irrigation District
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.