Thousand Oaks Tap Water Quality Report
Thousand Oaks's water has 2 contaminants above EPA MCLGs. Consider using a certified water filter for additional protection.
No single water system serves most of Thousand Oaks (124,229 residents, Census 2024 estimate). Its large systems are THOUSAND OAKS WATER DEPT (EPA counts 53,157 people served, about 43% of Thousand Oaks's population); CAL AMERICAN WATER CO (EPA counts 66,369 people served, about 53% of Thousand Oaks's population); CAMROSA WATER DISTRICT (EPA counts 32,700 people served, about 26% of Thousand Oaks's population). EPA's counts may include people served outside Thousand Oaks, so each share is at most that. Check which one bills you: each system's figures are shown separately below.
- THOUSAND OAKS WATER DEPT: 36 contaminants tested, 2 above EPA MCLGs; health-based violations since 2020: 0
- CAL AMERICAN WATER CO: 36 contaminants tested, 2 above EPA MCLGs; health-based violations since 2020: 0
- CAMROSA WATER DISTRICT: 195 contaminants tested, 4 above EPA MCLGs; health-based violations since 2020: 0
Other systems listed for Thousand Oaks with results above guidelines: NAVAL BASE VENTURA COUNTY, POINT MUGU (2 above guidelines), RINCON WATER & ROAD WORKS (1 above guidelines), CAMROSA WATER DISTRICT (4 above guidelines), CALLEGUAS MUNICIPAL WATER DIST (2 above guidelines), CASITAS MUTUAL WATER COMPANY (1 above guidelines), CAL AMERICAN WATER CO (2 above guidelines), CALIFORNIA WATER SERVICE CO - WESTLAKE (2 above guidelines)
Water systems
3 large systems
Residents (Census 2024)
124,229
Health-based violations since 2020
0
THOUSAND OAKS WATER DEPT. EPA SDWA violation data as of Q2 2026 (downloaded 2026-07-09).
Latest sample on file
Aug 2025 · THOUSAND OAKS WATER DEPT
Utilities publish newer results in their annual water quality report (Consumer Confidence Report).
Is Thousand Oaks Tap Water Safe to Drink?
We recommend using a certified water filter for additional protection, especially for vulnerable populations like children, pregnant women, and those with compromised immune systems. Thousand Oaks's water has 2 contaminants above EPA health-based guidelines (MCLGs), while it meets federal legal limits.
THOUSAND OAKS WATER DEPT, Thousand Oaks's water system, serves 53,157 people. 8 other systems are listed for Thousand Oaks. Each system's results are listed under its own name, never added to THOUSAND OAKS WATER DEPT's. Water quality testing is conducted regularly and reported to the EPA. The latest sample on file for THOUSAND OAKS WATER DEPT is from Aug 2025.
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in California
Thousand Oaks Water Service Areas
What these numbers actually mean for Thousand Oaks, CA
We read Thousand Oaks, CA’s published record and send you a short report — which findings warrant a decision, which to ignore, and what to do about it. Including when the answer is nothing.
- 2 contaminants above EPA MCLGs
- 34 results on file
- 23 PFAS compounds on record
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Recommended Water Filters for Thousand Oaks
Based on Thousand Oaks's water quality data, these NSF-certified filters are recommended to remove contaminants above EPA MCLGs.
Culligan
ZeroWater
NSF Certified:
Flow Rate
1.9 gpm
Daily Production
1 gpd
Highlights:
- Compact design
- Easy to set up
- Affordable
- NSF-42, NSF-53, NSF-401 certified
Removes 19 contaminants:
+14 more
Strontium, Molybdenum, Fluoride, Uranium, Lead, Total PFAS, Chlorine, 25, Phosphorus, Bicarbonate, Calcium, Carbonate, Magnesium, Sodium
Santevia
Bath Filter
NSF Certified:
Flow Rate
0.36 gpm
Highlights:
- Organic cotton design reduces plastic used in construction
- Affordable upfront & ongoing cost
- The only bath filter that removed 100% chlorine with “normal” faster faucet flow
Removes 1 contaminants:
Waterdrop
A1
NSF Certified:
Flow Rate
1 gpm
Highlights:
- Performance certified
- Lower price than Philips
- Hot water dispensing
- Compact design
Removes 5 contaminants:
Whirlpool Corporation
W11256135
NSF Certified:
Capacity
1001 gal
Filter Life
3 mo
Flow Rate
0.7 gpm
Removes 19 contaminants:
+14 more
Benzene, Carbofuran, Chlorine (Free), Chlorine (Total), Chlorine Dioxide, Chlorobenzene, Cryptosporidium, Ethylbenzene, Lead, Mercury, Metolachlor, Tetrachloroethylene, Toxaphene, Turbidity
Test Your Water Quality
Professional laboratory testing provides accurate, detailed analysis of your drinking water.
SimpleLab
Advanced Home Water Test
$269
Comprehensive water analysis testing over 200 contaminants including bacteria, heavy metals, and chemical compounds.
Tap Score
Advanced Microplastics Test
$829
Cutting-edge testing for microplastics particles in drinking water using advanced laboratory techniques.
Tap Score
Haloacetic Acids (HAA9) Test
$275
Tests for disinfection byproducts formed when chlorine reacts with organic matter in water treatment.
What Thousand Oaks's water readings can explain
We publish a city-level hardness figure for Thousand Oaks, resolved from its water systems where they report one and estimated from county sampling where they do not. Each page starts with the hot-tap and cold-tap check, then shows what your own water system reported.
On a private well near Thousand Oaks? Public-water results do not apply to private wells. See Ventura County well water testing and USGS risk data — modeled arsenic, nitrate, and the tests to run.
Water softener cost and installation in Thousand Oaks
Thousand Oaks's tap water measures 6.9 grains per gallon (118.0 mg/L) — moderately hard on the USGS scale, below the range where scale is usually worth treating.
Water softener cost for 6.9 gpg water in Thousand Oaks — equipment and local installation labour for your ZIP code, with the sizing arithmetic shown in full. For the national picture first, read what a water softener costs — equipment, installation labour and ten-year ownership, each separated out. For California as a whole, read water softener cost in California — priced against the plumber wage published for the state.
Frequently Asked Questions About Thousand Oaks Tap Water
Thousand Oaks's water has 2 contaminants above EPA MCLGs. While the water meets federal legal limits, we recommend using a certified water filter for additional protection, especially for vulnerable populations like children, pregnant women, and those with compromised immune systems.
Spotted something off on this page?
Residents keep our data honest.
This form corrects our data; it does not reach THOUSAND OAKS WATER DEPT. For a problem with your water now (discolored water, no water, low pressure, a leak), contact THOUSAND OAKS WATER DEPT directly.
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