Here is what the EPA's own data shows about tap water in Oakdale. According to EPA SDWIS data retrieved July 2026, Oakdale is served by 17 active community water systems, together reported to serve about 27,067 people.
As of July 2026, EPA records show 16 violations across the community water system(s) serving Oakdale, 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.
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.
Oid-Oakdale Rural Water System #1
1,570 served · groundwater · PWSID CA5000433
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.
Heritage Hills Mhp
425 served · groundwater · PWSID PA6370041
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.
Oid #51 - Sunset Oaks #10
287 served · groundwater · PWSID CA5000317
Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Oid #46 - Sunset Oaks
269 served · groundwater · PWSID CA5000014
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.
North Oaks Mutual Water Co
234 served · groundwater · PWSID CA5000237
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 2023. EPA records do not show all of these as returned to compliance.
Tahama Village Mobile Home Park
200 served · groundwater · PWSID CA3900602
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2001 and July 2005. 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 April 2000. All have since returned to compliance, per EPA records.
Oid #22 - Williams Tract
150 served · groundwater · PWSID CA5000015
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.
Oid #45
144 served · groundwater · PWSID CA5000013
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.
Country Squire Mobile Estates & Water Sy
131 served · groundwater · PWSID CA3900607
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 October 2014 and October 2023. 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 3 times between July 2001 and July 2011. All have since returned to compliance, per EPA records.
Twin Cypress Mobile Home Park
112 served · groundwater · PWSID CA5000071
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.
4n Mobilehome Park
65 served · groundwater · PWSID CA5000082
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.
Lone Pine Mhp
64 served · groundwater · PWSID CA5000049
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.
Tully Mobile Estates
56 served · groundwater · PWSID CA5000067
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.
Country Village Mobile Home Park
50 served · groundwater · PWSID CA5800824
Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in May 2019. The EPA record lists a level of 12.25 UG/L; the limit (MCL) is 10 UG/L. EPA records do not show all of these as returned to compliance.
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. All have since returned to compliance, per EPA records.
Country Leisure Mobile Estates
40 served · groundwater · PWSID CA1100413
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.
Pleasant Prairie Mhp
35 served · groundwater · PWSID WI2300117
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.