Here is what the EPA's own data shows about tap water in Rosemead. According to EPA SDWIS data retrieved July 2026, Rosemead is served by 15 active community water systems, together reported to serve about 225,761 people.
As of July 2026, EPA records show 52 violations across the community water system(s) serving Rosemead, going back to the earliest EPA record. 5 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.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in October 2022. EPA records do not show all of these as returned to compliance.
Cal/Am Water Company - San Marino
47,995 served · surface water · PWSID CA1910139
Monitoring 1,2,3-Trichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between November 2022 and January 2023. All have since returned to compliance, per EPA records.
Monitoring Perchlorate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2022. 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 once in January 2020. All have since returned to compliance, per EPA records.
San Gabriel County Wd
39,345 served · groundwater · PWSID CA1910144
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.
Cal-Am Water Company - Duarte
24,773 served · groundwater · PWSID CA1910186
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.
Cal/Am Water Company - Baldwin Hills
20,724 served · surface water · PWSID CA1910052
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.
Cal-Am Water Company - East Pasadena
9,949 served · groundwater · PWSID CA1910020
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.
Bellflower Municipal Water System
5,999 served · surface water · PWSID CA1910018
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.
Amarillo Mutual Water Company
3,134 served · groundwater · PWSID CA1910002
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2019 and October 2022. 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 7 times between January 2019 and October 2022. 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 once in January 2022. All have since returned to compliance, per EPA records.
Monitoring Perchlorate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2022. 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 January 1998 and January 2001. All have since returned to compliance, per EPA records.
Cal American Wc - Las Posas Estates
2,039 served · surface water · PWSID CA5610081
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.
Cal American Water Company - Piru
2,003 served · groundwater · PWSID CA5610021
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 in May 2021. All have since returned to compliance, per EPA records.
Cal American Wc - Rio Plaza
1,709 served · groundwater · PWSID CA5610010
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 2001. All have since returned to compliance, per EPA records.
Cal American - Yerba Buena
690 served · groundwater · PWSID CA5610006
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 December 1997. All have since returned to compliance, per EPA records.
Golden Sands Mobile Home Park
450 served · groundwater · PWSID CA1900649
Health-based LEAD AND COPPER RULE REVISIONS: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. The EPA record for these does not include a measured level. 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 October 2024. EPA records do not show all of these as returned to compliance.
Sce/Big Creek Powerhouse 1
104 served · surface water · PWSID CA1009111
Health-based Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in April 2018. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in July 2015. The EPA record lists a level of 0.064 MG/L; the limit (MCL) is 0.06 MG/L. 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 1993 and October 2014. 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 8 times between September 2007 and April 2008. 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 2 times in January 2008. All have since returned to compliance, per EPA records.
Sce Bishop Creek Plant 4
38 served · groundwater · PWSID CA1400078
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 1993. 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 July 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.