Drinking water quality · 2024
· Verified
What's in Thousand Oaks, CA tap water
31 contaminants were measured in the Thousand Oaks, CA water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 31
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
state-level CCR
Where your water comes from · EPA SDWIS
Thousand Oaks, CA buys its drinking water from CALLEGUAS MUNICIPAL WATER DIST, CAL AMERICAN WATER CO, and 1 more.
Source
0sources
Treatment
0treatment plants
Distribution
0storage units
Also buys water from CALLEGUAS MUNICIPAL WATER DIST, CAL AMERICAN WATER CO, and 1 more.
Source: EPA SDWIS facilities inventory. Methodology.
Historical readings · EPA Six-Year Review (2012–2019)
11 historically-detected contaminants in Thousand Oaks, CA
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
TTHM worst: 2015 | 0.0544 mg/L within | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
HAA5 worst: 2017 | 0.012 mg/L within | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
DBAA worst: 2012 | 0.006 mg/L | — | '12'13'14'15'16'17'18'19 |
DCAA worst: 2012 | 0.003 mg/L | — | '12'13'14'15'16'17'18'19 |
MBAA worst: 2013 | 0.002 mg/L | — | '13'14'15'16 |
MCAA worst: 2015 | 0.003 mg/L | — | '15 |
TCAA worst: 2012 | 0.001 mg/L | — | '12'13'14'15'16'17 |
BROMODICHLOROMETHANE worst: 2012 | 0.0064 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.0106 mg/L | — | '12'13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.0034 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.0102 mg/L | — | '12'13'14'15'16'17'18'19 |
PWSID CA5610020 · Source: EPA Six-Year Review 4 (2012–2019). Values are the highest detection in each calendar year; non-detect years are omitted. Year tags above show every year with a detection.
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| BromateA disinfection byproduct formed when bromide-containing water is treated with ozone. | 0–5.4 ug/LReported levelMWD Jensen Plant 98% of Supply | 10 ug/LMCL | Within the limit |
+By source (2)— MWD Jensen Plant 98% of Supply, Calleguas LBWFP 2% of Supply
| |||
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.6–1 mg/LReported levelMWD Jensen Plant 98% of Supply | 2 mg/LMCL | Within the limit |
| SulfateA naturally occurring mineral from rock and soil. | 102–103 mg/LReported levelCalleguas LBWFP 2% of Supply | 500 mg/LMCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
| ChlorideA naturally occurring salt compound. | 99–100 mg/LReported levelCalleguas LBWFP 2% of Supply | 500 mg/LMCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0.5 mg/LReported levelMWD Jensen Plant 98% of Supply | 10 mg/LMCL | Within the limit |
+By source (2)— MWD Jensen Plant 98% of Supply, Calleguas LBWFP 2% of Supply
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 773–790 %Reported levelCalleguas LBWFP 2% of Supply | 1600 %MCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.14 NTUReported levelCalleguas LBWFP | 0.3 NTUMCL | Within the limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 410–450 mg/LReported levelCalleguas LBWFP 2% of Supply | 1000 mg/LMCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
| OdorA measure of detectable smell in the water. | 1 %Reported levelMWD Jensen Plant 98% of Supply | 3 %MCL | Within the limit |
+By source (2)— MWD Jensen Plant 98% of Supply, Calleguas LBWFP 2% of Supply
| |||
| ColorA measure of visible tint in the water. | 1 %Reported levelMWD Jensen Plant 98% of Supply | 15 %MCL | Within the limit |
+By source (2)— MWD Jensen Plant 98% of Supply, Calleguas LBWFP 2% of Supply
| |||
| AlkalinityA measure of the water's capacity to neutralize acids. | 120–130 mg/LReported levelCalleguas LBWFP | None set | Detected — no federal limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
| HardnessA measure of dissolved calcium and magnesium minerals. | 160–165 mg/LReported levelCalleguas LBWFP | None set | Detected — no federal limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
| pHA measure of how acidic or basic the water is. | 8.1–8.3 %Reported levelCalleguas LBWFP | None set | Detected — no federal limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 2.6–2.8 mg/LReported levelCalleguas LBWFP | None set | Detected — no federal limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 1.18–1.94 mg/LReported levelMWD Jensen Plant 98% of Supply | 4 mg/LMCL | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| AluminumA common element sometimes used as a treatment coagulant. | 52–91 ug/LReported levelMWD Jensen Plant 98% of Supply | 200 ug/LMCL | Within the limit |
+By source (2)— MWD Jensen Plant 98% of Supply, Calleguas LBWFP 2% of Supply
| |||
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | 2–4 ug/LReported levelCalleguas LBWFP 2% of Supply | 10 ug/LMCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0–5.4 ug/LReported levelMWD Jensen Plant 98% of Supply | 15 ug/LAction level | Within the limit |
| BoronA naturally occurring element from rock and soil. | 0.27–0.28 mg/LReported levelCalleguas LBWFP | 1 mg/LNL | Within the limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
| CopperA metal that enters water from corroding household plumbing. | 0–0.2 mg/LReported levelMWD Jensen Plant 98% of Supply | 1.3 mg/LAction level | Within the limit |
| SeleniumA trace element from natural deposits and industrial discharge. | 0–6 ug/LReported levelCalleguas LBWFP 2% of Supply | 50 ug/LMCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
| ZincA naturally occurring metal that can also enter water from corroding pipes. | 0.06 mg/LReported levelCalleguas LBWFP 2% of Supply | 5 mg/LMCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
| CalciumA naturally occurring mineral that contributes to water hardness. | 38–39 mg/LReported levelMWD Jensen Plant | None set | Detected — no federal limit |
+By source (2)— MWD Jensen Plant, Calleguas LBWFP
| |||
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 17 mg/LReported levelCalleguas LBWFP | None set | Detected — no federal limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
| PotassiumA naturally occurring mineral from rock and soil. | 4 mg/LReported levelCalleguas LBWFP | None set | Detected — no federal limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
| SodiumA naturally occurring salt component. | 86–91 mg/LReported levelCalleguas LBWFP | None set | Detected — no federal limit |
+By source (2)— Calleguas LBWFP, MWD Jensen Plant
| |||
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 2–3 pCi/LReported levelMWD Jensen Plant 98% of Supply | 20 pCi/LMCL | Within the limit |
+By source (2)— MWD Jensen Plant 98% of Supply, Calleguas LBWFP 2% of Supply
| |||
| Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances. | 5.4–5.6 pCi/LReported levelCalleguas LBWFP 2% of Supply | 50 pCi/LMCL | Within the limit |
+By source (2)— Calleguas LBWFP 2% of Supply, MWD Jensen Plant 98% of Supply
| |||
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0 %Reported levelMWD Jensen Plant | 5 %MCL | None detected |
Source: Thousand Oaks, CA's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.
People also ask about Thousand Oaks, CA's water
+Is Thousand Oaks, CA tap water safe to drink in 2024?
Every one of the 31 contaminants measured in Thousand Oaks, CA's 2024 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Thousand Oaks, CA tap water?
31 contaminants were measured in Thousand Oaks, CA's 2024 Consumer Confidence Report, spanning metals, physical & aggregate, and inorganic chemicals. 23 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Where does the data on this page come from?
Every value is transcribed from Thousand Oaks, CA's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Thousand Oaks, CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.