Is Thousand Oaks, CA tap water safe?

Data: U.S. EPA · How we read the data · How we check it

No federal limits exceeded in EPA data for Las Virgenes Municipal Water District.

4 public water systems serve parts of Thousand Oaks. The largest, Las Virgenes Municipal Water District, serves 77,562 people. Your water bill names your system.

Largest system

Las Virgenes Municipal Water District

77,562 people · Surface water · EPA ID CA1910225

Buys treated water from Metropolitan Water District of SO. Cal..

PFAS	Highest average	Limit	Status
PFOA Not detected	–	4 ppt	Not detected
PFOS Not detected	–	4 ppt	Not detected
PFHxS Not detected	–	10 ppt	Not detected
PFNA Not detected	–	10 ppt	Not detected
HFPO-DA (GenX) Not detected	–	10 ppt	Not detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 0 ppb at the 90th percentile (Dec 2024, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Full Las Virgenes Municipal Water District results

Across California, 129 of 691 water systems EPA tested had PFAS above a 2024 federal limit, and 26 systems were above the lead action level in results from the last five years. California results.

Thousand Oaks homes and lead pipes

56%

of homes built before 1980 (California 56%, US 50%)

built before 1950 (California 14%)

29%

of households rent (California 44%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Thousand Oaks city (tables B25034, B25003). Estimates for small places have a margin of error.

Which system serves your ZIP code

Based on the ZIP codes each system reported serving. Boundaries don't follow ZIP lines exactly, so your water bill is the final word.

System	ZIP codes in Thousand Oaks
Las Virgenes Municipal Water District 77,562 people	91361, 91362
California American Water 66,809 people	91320, 91360

Other water systems serving Thousand Oaks

California American Water
66,809 people · Purchased surface water · California · reported ZIPs here
Lithium above screening level
City of Thousand Oaks Water Department
54,770 people · Purchased surface water · California · lists this city
No PFAS above limits
California Water Service – Westlake
19,544 people · Purchased surface water · California · reported ZIPs here
No PFAS above limits

How nearby cities compare

City	Main water system	PFAS
Moorpark 6 mi Ventura Cwwd No. 1 – Moorpark Water System	Ventura Cwwd No. 1 – Moorpark Water System	None above limits
Simi Valley 9 mi Ventura County Waterworks District No. 8 – Simi Valley	Ventura County Waterworks District No. 8 – Simi Valley	None above limits
Camarillo 9 mi Camarillo Water Dept	Camarillo Water Dept	None above limits
Santa Paula 16 mi City of Santa Paula	City of Santa Paula	None above limits
Oxnard 19 mi Oxnard Water Dept	Oxnard Water Dept	None above limits
Ventura 22 mi Ventura Water Department	Ventura Water Department	None above limits

Questions

Is Thousand Oaks tap water safe to drink?

Las Virgenes Municipal Water District has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Thousand Oaks, CA?

4 public water systems serve parts of Thousand Oaks. The largest is Las Virgenes Municipal Water District (77,562 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Thousand Oaks tap water have PFAS?

None detected above EPA's reporting limits. Las Virgenes Municipal Water District had no PFAS detected in EPA's 2023–2025 testing. "Not detected" means below the reporting limit (about 2 to 20 ppt), not proven zero.

Do Thousand Oaks homes have lead pipes?

Census estimates put 56% of Thousand Oaks homes as built before 1980 (California: 56%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Las Virgenes Municipal Water District's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.