Your Local Water Profile: Thousand Oaks
This profile explains what the applicable water provider reported for Thousand Oaks, what those results may mean throughout a home, and where property-specific testing or inspection may still be needed.
First, confirm your water provider.
Water service can vary by address. Confirm the provider shown on your water bill before applying provider-specific results.
What the official water report says
Your water at a glance
City of Thousand Oaks
The report lists hardness as 148 ppm; this is hard on the USGS scale.
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
California American Water
The report lists hardness as 140 mg/L; this is hard on the USGS scale.
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
Camrosa Water District
The report lists hardness as 148 ppm; this is hard on the USGS scale.
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
City of Thousand Oaks Water System — compliance, as reported
The report states: “The quality of our drinking water meets all State requirements for safe water.”
Violations or advisories, as reported: The report explicitly states that the City’s water supply met or exceeded all State and Federal standards in 2024, and the quality of the water delivered consistently meets all State standards. No violations or advisories were reported.
California American Water - Thousand Oaks — compliance, as reported
The report states: “We are pleased to report that in 2025, your water met state and federal drinking water requirements. [p. 2]”
CALIFORNIA WATER SERVICE CO - WESTLAKE — compliance, as reported
The report states: “Importantly, the reports confirm that Cal Water met all primary and secondary, federal and state water quality standards set for drinking water in 2024. [p. 5]”
Camrosa Water District — compliance, as reported
The report states: “We are pleased to present to you this year’s annual water quality report. This report is a snapshot of last year’s water quality covering all testing performed between January 1 and December 31, 2024. Included are details about your sources of water, what it contains, and how it compares to standards set by regulatory agencies. Our constant goal is to provide you with a safe and dependable supply of drinking water.”
Violations or advisories, as reported: During the past year, we were required to conduct one Level 1 assessment, which we completed. In addition, we were required to take one corrective action, which we completed. No violations were reported for regulated or secondary substances.
The Three C's — 1 of 3
Chemistry
What does this water tend to do in a home?
City of Thousand Oaks Water System
Alkalinity, total as CaCO3
The utility reported: 98 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Calcium
The utility reported: 38 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Corrosivity
The utility reported: 12.2 AI
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Hardness (Total Hardness)
The utility reported: 148 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Magnesium
The utility reported: 14 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
pH
The utility reported: 8.3 pH units
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Sodium
The utility reported: 46 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Specific Conductance
The utility reported: 510 µS/cm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Sulfate
The utility reported: 90 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Total Dissolved Solids
The utility reported: 306 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Chloride
The utility reported: 40 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Color
The utility reported: 1 Units
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Odor Threshold
The utility reported: 1 TON Units
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Combined Filter Effluent Turbidity
The utility reported: 0.04 NTU
MWD Jensen Plant 98% of Supply · report p. PAGE 4 · official report
Aluminum
The utility reported: 62 ppb
MWD Jensen Plant 98% of Supply · report p. PAGE 4 · official report
Arsenic
The utility reported: 3.0 ppb
Calleguas LBWFP 2% of Supply · report p. PAGE 4 · official report
Fluoride
The utility reported: 0.7 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 4 · official report
Nitrate (as N)
The utility reported: 0.5 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 4 · official report
Total Trihalomethanes (TTHM)
The utility reported: 17.8 ppb
Highest LRAA · report p. PAGE 5 · official report
California American Water - Thousand Oaks
Total Hardness (as CaCO3)
The utility reported: 140 mg/L
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Calcium
The utility reported: 31 - 34 ppm
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Magnesium
The utility reported: 13 - 14 ppm
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Alkalinity
The utility reported: 96 - 100 ppm
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Total Dissolved Solids
The utility reported: 297 ppm
SECONDARY REGULATED SUBSTANCES · report p. 8 · official report
Lead 90th Percentile
The utility reported: 3.0 ppb
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
Copper 90th Percentile
The utility reported: 0.132 ppm
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
Chloramines
The utility reported: 2.4 ppm
DISINFECTANTS & DISINFECTION BY PRODUCTS · report p. 5 · official report
Chlorine
The utility reported: 1.61 ppm
DISINFECTANTS & DISINFECTION BY PRODUCTS · report p. 5 · official report
Corrosivity (k)
The utility reported: 12.2
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
CALIFORNIA WATER SERVICE CO - WESTLAKE
General mineral and treatment characteristics were not itemized in this provider's reviewed report. The official report link in the Sources section below is the authoritative record.
Camrosa Water District
Hardness, Total [as CaCO3]
The utility reported: 148 ppm
Calleguas Imported Water · report p. PAGE 7 · official report
Specific Conductance
The utility reported: 510 µS/cm
Calleguas Imported Water · report p. PAGE 7 · official report
Total Dissolved Solids
The utility reported: 306 ppm
Calleguas Imported Water · report p. PAGE 7 · official report
Odor, Threshold
The utility reported: 1 TON
Calleguas Imported Water · report p. PAGE 7 · official report
Nitrate [as nitrogen]
The utility reported: 0.5 ppm
Calleguas Imported Water · report p. PAGE 5 · official report
The Three C's — 2 of 3
Contaminants
What was reported, and what do the applicable standards mean?
Legal limit — maximum contaminant level (MCL)
The highest level legally allowed in public drinking water under the applicable rule. Do not use MCL as a generic label for goals, action levels, notification levels, or independent guidelines. It is different from a non-enforceable health goal.
California health goal — public health goal (PHG)
A non-enforceable health-protective target developed for standard-setting context. It is not the California legal limit.
Federal health goal — maximum contaminant level goal (MCLG)
A non-enforceable EPA public-health target used in setting standards. It is not the legal limit.
Legal disinfectant-residual limit — maximum residual disinfectant level (MRDL)
The highest level of a drinking-water disinfectant allowed under the applicable rule. It is not an MCL for a contaminant.
City of Thousand Oaks Water System — regulated contaminants reported as detected (15)
Combined Filter Effluent Turbidity
The utility reported: 0.04 NTU
Benchmark: 0.3
Violation per report: No
Typical source, per the report: Soil runoff
Reported constituent · report p. PAGE 4 · official report
Total Coliform Bacteria
The utility reported: 0 % of Samples
Benchmark: 5% · Health goal (goal): 0 — not an enforceable limit
Violation per report: No
Typical source, per the report: Naturally present in the environment
Reported constituent · report p. PAGE 4 · official report
Aluminum
The utility reported: 62 ppb
Reported range: 52 - 91
Benchmark: 1000 · Health goal (goal): 600 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; residue from water treatment process
Reported constituent · report p. PAGE 4 · official report
Arsenic
The utility reported: 3.0 ppb
Reported range: 2.0 - 4.0
Benchmark: 10 · Health goal (goal): 0.004 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; runoff from orchards; electronics production wastes
Reported constituent · report p. PAGE 4 · official report
Copper
The utility reported: 0.15 ppm
Benchmark: AL=1.3 · Health goal (goal): 0.3 — not an enforceable limit
Violation per report: No
Typical source, per the report: Internal corrosion of household plumbing systems; erosion of natural deposits
Reported constituent · report p. PAGE 4 · official report
Fluoride
The utility reported: 0.7 ppm
Reported range: 0.6 - 1.0
Benchmark: 2.0 · Health goal (goal): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Water additive that promotes strong teeth
Reported constituent · report p. PAGE 4 · official report
Lead
The utility reported: 2.2 ppb
Reported range: ND - 5.4
Benchmark: AL=15 · Health goal (goal): 0.2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Internal corrosion of household pipes; erosion of natural deposits
Reported constituent · report p. PAGE 4 · official report
Nitrate (as N)
The utility reported: 0.5 ppm
Reported range: 0.5
Benchmark: 10 · Health goal (goal): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Runoff & leaching from fertilizer use; erosion of natural deposits
Reported constituent · report p. PAGE 4 · official report
Selenium
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND - 6
Benchmark: 50 · Health goal (goal): 30 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; discharge from oil & metal refineries
Reported constituent · report p. PAGE 4 · official report
Gross Beta Particle Activity
The utility reported: 5.5 pCi/L
Reported range: 5.4 - 5.6
Benchmark: 50 · Health goal (goal): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Decay of natural & man-made deposits
Reported constituent · report p. PAGE 5 · official report
Uranium
The utility reported: 2 pCi/L
Reported range: 2.0 - 3.0
Benchmark: 20 · Health goal (goal): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Reported constituent · report p. PAGE 5 · official report
Bromate
The utility reported: 3.1 ppb
Reported range: ND - 5.4
Benchmark: 10 · Health goal (goal): 0.1 — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water ozonation
Reported constituent · report p. PAGE 5 · official report
Total Chlorine Residual
The utility reported: 1.53 ppm
Reported range: 1.18 - 1.94
Benchmark: 4 · Health goal (goal): 4 — not an enforceable limit
Violation per report: No
Typical source, per the report: Drinking water disinfectant added for treatment
Reported constituent · report p. PAGE 5 · official report
Haloacetic Acids (HAA5)
The utility reported: 6.7 ppb
Reported range: 0 - 9.3
Benchmark: 60
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection
Reported constituent · report p. PAGE 5 · official report
Total Trihalomethanes (TTHM)
The utility reported: 17.8 ppb
Reported range: 13 - 20
Benchmark: 80
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection
Reported constituent · report p. PAGE 5 · official report
City of Thousand Oaks Water System — unregulated monitoring and secondary (aesthetic) records (18)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Aluminum
The utility reported: 62 ppb
Reported range: 52 - 91
Typical source, per the report: Erosion of natural deposits; residue from water treatment processes
Reported constituent · report p. PAGE 5 · official report
Chloride
The utility reported: 40 ppm
Reported range: 39 - 41
Typical source, per the report: Runoff/leaching from natural deposits; seawater influence
Reported constituent · report p. PAGE 5 · official report
Color
The utility reported: 1 Units
Reported range: 1
Typical source, per the report: Naturally occurring organic materials
Reported constituent · report p. PAGE 5 · official report
Odor Threshold
The utility reported: 1 TON Units
Reported range: 1
Typical source, per the report: Naturally occurring organic materials
Reported constituent · report p. PAGE 5 · official report
Specific Conductance
The utility reported: 510 µS/cm
Reported range: 498 - 522
Typical source, per the report: Substances that form ions when in water; seawater influence
Reported constituent · report p. PAGE 5 · official report
Sulfate
The utility reported: 90 ppm
Reported range: 89 - 92
Typical source, per the report: Runoff/leaching from natural deposits
Reported constituent · report p. PAGE 5 · official report
Total Dissolved Solids
The utility reported: 306 ppm
Reported range: 291 - 322
Typical source, per the report: Runoff/leaching from natural deposits
Reported constituent · report p. PAGE 5 · official report
Zinc
The utility reported: Not detected at the report's stated reporting limit ppm
Reported range: ND
Typical source, per the report: Runoff/leaching from natural deposits
Reported constituent · report p. PAGE 5 · official report
Alkalinity, total as CaCO3
The utility reported: 98 ppm
Reported range: 94 - 101
Reported constituent · report p. PAGE 5 · official report
Boron
The utility reported: 0.17 ppm
Reported range: 0.17
Reported constituent · report p. PAGE 5 · official report
Calcium
The utility reported: 38 ppm
Reported range: 38 - 39
Reported constituent · report p. PAGE 5 · official report
Corrosivity
The utility reported: 12.2 AI
Reported range: 12.2
Reported constituent · report p. PAGE 5 · official report
Hardness (Total Hardness)
The utility reported: 148 ppm
Reported range: 143 - 153
Reported constituent · report p. PAGE 5 · official report
Magnesium
The utility reported: 14 ppm
Reported range: 13 - 14
Reported constituent · report p. PAGE 5 · official report
pH
The utility reported: 8.3 pH units
Reported range: 8.2 - 8.3
Reported constituent · report p. PAGE 5 · official report
Potassium
The utility reported: 2.6 ppm
Reported range: 2.6
Reported constituent · report p. PAGE 5 · official report
Sodium
The utility reported: 46 ppm
Reported range: 46
Reported constituent · report p. PAGE 5 · official report
Total Organic Carbon
The utility reported: 2.4 ppm
Reported range: 2.0 - 2.5
Reported constituent · report p. PAGE 5 · official report
California American Water - Thousand Oaks — regulated contaminants reported as detected (12)
Lead
The utility reported: 3.0 ppb
Reported range: ND to 5.0
AL: 15 · Health goal (MCLG): 0.2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Corrosion of household plumbing systems.
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
Copper
The utility reported: 0.132 ppm
Reported range: ND to 0.263
AL: 1.3 · Health goal (MCLG): 1.3 — not an enforceable limit
Violation per report: No
Typical source, per the report: Corrosion of household plumbing systems.
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
Total Coliform
The utility reported: 1.01% %
TT: Less than 5% · Health goal (MCLG): 0 — not an enforceable limit
Violation per report: No
Typical source, per the report: Naturally present in the environment
REVISED TOTAL COLIFORM RULE · report p. 4 · official report
Turbidity
The utility reported: 0.06 NTU
Reported range: 100%
TT: % of samples <=0.3 NTU · Health goal (MCLG): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: Soil runoff
TURBIDITY · report p. 4 · official report
Total Organic Carbon
The utility reported: 2.3 ppm
Reported range: 1.9 - 2.4
TT: TT · Health goal (MCLG): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: Naturally present in the environment
TREATMENT BYPRODUCTS PRECURSOR REMOVAL · report p. 4 · official report
Haloacetic Acids
The utility reported: 5.4 ppb
Reported range: 1.0 - 5.8
Legal limit (MCL): 60 · Health goal (MCLG): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection.
DISINFECTANTS & DISINFECTION BY PRODUCTS · report p. 5 · official report
Total Trihalomethanes
The utility reported: 14 ppb
Reported range: 8.9 - 18
Legal limit (MCL): 80 · Health goal (MCLG): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection.
DISINFECTANTS & DISINFECTION BY PRODUCTS · report p. 5 · official report
Chloramines
The utility reported: 2.4 ppm
Reported range: 1.7 - 2.8
MRDL: 4 · Health goal (MRDLG): 4 — not an enforceable limit
Violation per report: No
Typical source, per the report: Water additive used to control microbes.
DISINFECTANTS & DISINFECTION BY PRODUCTS · report p. 5 · official report
Chlorine
The utility reported: 1.61 ppm
Reported range: 1.3 - 2.01
MRDL: 4 · Health goal (MRDLG): 4 — not an enforceable limit
Violation per report: No
Typical source, per the report: Water additive used to control microbes.
DISINFECTANTS & DISINFECTION BY PRODUCTS · report p. 5 · official report
Aluminum
The utility reported: 0.06 ppm
Reported range: ND - 0.079
Legal limit (MCL): 1.0 · Health goal (PHG): 0.6 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits.
PRIMARY REGULATED SUBSTANCES · report p. 6 · official report
Fluoride
The utility reported: 0.7 ppm
Reported range: 0.2 - 1.1
Legal limit (MCL): 2 · Health goal (PHG): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; water additive which promotes strong teeth; discharge from fertilizer and aluminum factories.
PRIMARY REGULATED SUBSTANCES · report p. 6 · official report
Uranium
The utility reported: 2.0 pCi/L
Reported range: 2 - 3
Legal limit (MCL): 20 · Health goal (PHG): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits.
PRIMARY REGULATED SUBSTANCES · report p. 7 · official report
California American Water - Thousand Oaks — unregulated monitoring and secondary (aesthetic) records (22)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Chloride
The utility reported: 49 ppm
Reported range: 56 - 52
Typical source, per the report: Leaching from natural deposits
SECONDARY REGULATED SUBSTANCES · report p. 8 · official report
Color
The utility reported: 1 color units
Reported range: 1
Typical source, per the report: Naturally occurring organic materials
SECONDARY REGULATED SUBSTANCES · report p. 8 · official report
Specific Conductance
The utility reported: 504 mmhos/cm
Reported range: 503 - 504
Typical source, per the report: Substances that form ions when in water
SECONDARY REGULATED SUBSTANCES · report p. 8 · official report
Sulfate
The utility reported: 71 ppm
Reported range: 64 - 78
Typical source, per the report: Leaching from natural deposits
SECONDARY REGULATED SUBSTANCES · report p. 8 · official report
Total Dissolved Solids
The utility reported: 297 ppm
Reported range: 293 - 301
Typical source, per the report: Leaching from natural deposits
SECONDARY REGULATED SUBSTANCES · report p. 8 · official report
Alkalinity
The utility reported: 96 - 100 ppm
Typical source, per the report: Naturally occurring.
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Boron
The utility reported: 0.2 ppm
Typical source, per the report: Naturally occurring
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Corrosivity (k)
The utility reported: 12.2
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Calcium
The utility reported: 31 - 34 ppm
Typical source, per the report: Leaching from natural deposits
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Magnesium
The utility reported: 13 - 14 ppm
Typical source, per the report: Leaching from natural deposits
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
pH
The utility reported: 8.3 - 8.4
Typical source, per the report: pH is a measure of the acid/base properties of water.
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Potassium
The utility reported: 2.8 - 2.9 ppm
Typical source, per the report: Leaching from natural deposits
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Sodium
The utility reported: 46 - 50 ppm
Typical source, per the report: Erosion from naturally occurring deposits: Used in water softener regeneration.
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
N-Nitrosodimethylamine (NDMA)
The utility reported: 2.1 ppt
Typical source, per the report: Man made, used in industrial applications
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Total Hardness (as CaCO3)
The utility reported: 140 mg/L
Typical source, per the report: Naturally occurring.
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Perfluorooctanoic acid (PFOA)
The utility reported: 0.4 ppt
Reported range: ND to 1.0
UNREGULATED CHEMICALS · report p. 10 · official report
Perfluorooctanesulfonic acid (PFOS)
The utility reported: 0.7 ppt
Reported range: 0.6 to 0.7
UNREGULATED CHEMICALS · report p. 10 · official report
Perfluorobutanoic acid (PFBA)
The utility reported: 2.0 ppt
Reported range: 1.7 to 2.3
UNREGULATED CHEMICALS · report p. 10 · official report
Perfluoroheptanoic acid (PFHpA)
The utility reported: 0.2 ppt
Reported range: ND to 0.5
UNREGULATED CHEMICALS · report p. 10 · official report
Perfluorohexanoic acid (PFHxA)
The utility reported: 0.8 ppt
Reported range: 0.7 to 0.9
UNREGULATED CHEMICALS · report p. 10 · official report
Perfluoropentanoic acid (PFPeA)
The utility reported: 0.7 ppt
Reported range: 0.6 to 0.7
UNREGULATED CHEMICALS · report p. 10 · official report
Lithium
The utility reported: 16 ppb
Reported range: 15 to 18
Typical source, per the report: commercial uses
UNREGULATED CHEMICALS · report p. 10 · official report
CALIFORNIA WATER SERVICE CO - WESTLAKE — regulated contaminants reported as detected (0)
No itemized regulated-detection records were extracted from this provider's reviewed report. That is a limit of the extraction, not a claim that nothing was detected — the official report linked below is authoritative.
Camrosa Water District — regulated contaminants reported as detected (20)
Chlorine Residual
The utility reported: LRAA 1.15 ppm
Reported range: ND - 2.4
Benchmark: 4 · Health goal (goal): 4 — not an enforceable limit
Violation per report: No
Typical source, per the report: Water additive used to control microbes
Reported constituent · report p. PAGE 4 · official report
Haloacetic Acids [HAAs]
The utility reported: LRAA 5.0 ppb
Reported range: ND - 8
Benchmark: 60 · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection
Reported constituent · report p. PAGE 4 · official report
Trihalomethanes [TTHMs]
The utility reported: LRAA 13.0 ppb
Reported range: ND - 17
Benchmark: 80 · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection
Reported constituent · report p. PAGE 4 · official report
Turbidity
The utility reported: 0.67 NTU
Reported range: 0.05 - 0.67
Benchmark: TT · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: Soil runoff
Reported constituent · report p. PAGE 4 · official report
Turbidity (lowest monthly percent of samples meeting limit)
The utility reported: 98.8% of samples <= 0.3
Reported range: NA
Benchmark: TT · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: Soil runoff
Reported constituent · report p. PAGE 4 · official report
Copper
The utility reported: 0.22 ppm
Reported range: 0-0.55
Benchmark: 1.3 · Health goal (goal): 0.3 — not an enforceable limit
Violation per report: No
Typical source, per the report: Internal corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives
Reported constituent · report p. PAGE 4 · official report
Lead
The utility reported: 0 ppb
Reported range: 0-5
Benchmark: 15 · Health goal (goal): 0.2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Internal corrosion of household water plumbing systems; discharges from industrial manufacturers; erosion of natural deposits
Reported constituent · report p. PAGE 4 · official report
Aluminum
The utility reported: 0.062 ppm
Reported range: 0.052–0.091
Benchmark: 1 · Health goal (goal): 0.6 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; Residue from some surface water treatment processes
Reported constituent · report p. PAGE 5 · official report
Arsenic
The utility reported: 0.06 ppb
Reported range: 0.04–0.08
Benchmark: 10 · Health goal (goal): 0.004 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; Runoff from orchards; Glass and electronics production wastes
Reported constituent · report p. PAGE 5 · official report
Bromate
The utility reported: 3.1 ppb
Reported range: ND–5.4
Benchmark: 10 · Health goal (goal): 0.1 — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection
Reported constituent · report p. PAGE 5 · official report
Chlorine
The utility reported: 0.0023 ppm
Reported range: 0.0017–0.0028
Benchmark: [4.0 (as Cl2)] · Health goal (goal): [4 (as Cl2)] — not an enforceable limit
Violation per report: No
Typical source, per the report: Drinking water disinfectant added for treatment
Reported constituent · report p. PAGE 5 · official report
Fluoride
The utility reported: 0.7 ppm
Reported range: 0.6–1.0
Benchmark: 2.0 · Health goal (goal): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; Water additive that promotes strong teeth; Discharge from fertilizer and aluminum factories
Reported constituent · report p. PAGE 5 · official report
Gross Beta Particle Activity
The utility reported: 0.11 pCi/L
Reported range: 0.108–0.112
Benchmark: 50 · Health goal (goal): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Decay of natural and human-made deposits
Reported constituent · report p. PAGE 5 · official report
Haloacetic Acids
The utility reported: 12.0 ppb
Reported range: 6.0–22.0
Benchmark: 60 · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection
Reported constituent · report p. PAGE 5 · official report
Heterotrophic Plate Count Bacteria
The utility reported: Not detected at the report's stated reporting limit CFU/mL
Reported range: ND–2
Benchmark: TT · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: Naturally present in the environment
Reported constituent · report p. PAGE 5 · official report
Nitrate [as nitrogen]
The utility reported: 0.5 ppm
Reported range: 0.5–0.5
Benchmark: 10 · Health goal (goal): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Runoff and leaching from fertilizer use; Leaching from septic tanks and sewage; Erosion of natural deposits
Reported constituent · report p. PAGE 5 · official report
Selenium
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND–0.12
Benchmark: 50 · Health goal (goal): 30 — not an enforceable limit
Violation per report: No
Typical source, per the report: Discharge from petroleum, glass, and metal refineries; Erosion of natural deposits; Discharge from mines and chemical manufacturers; Runoff from livestock lots (feed additive)
Reported constituent · report p. PAGE 5 · official report
Total Trihalomethanes
The utility reported: 21.8 ppb
Reported range: 13.0–36.0
Benchmark: 80 · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: By-product of drinking water disinfection
Reported constituent · report p. PAGE 5 · official report
Turbidity
The utility reported: 0.04 NTU
Reported range: NA
Benchmark: TT · Health goal (goal): NA — not an enforceable limit
Violation per report: No
Typical source, per the report: Soil runoff
Reported constituent · report p. PAGE 5 · official report
Uranium
The utility reported: 2.0 pCi/L
Reported range: 1.9–3.0
Benchmark: 20 · Health goal (goal): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Reported constituent · report p. PAGE 5 · official report
Camrosa Water District — unregulated monitoring and secondary (aesthetic) records (16)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Alkalinity
The utility reported: 98 ppm
Reported range: 94–101
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Boron
The utility reported: 0.17 ppm
Reported range: 0.17–0.17
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Calcium
The utility reported: 38 ppm
Reported range: 38–39
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Chlorate
The utility reported: 71 ppb
Reported range: 71–71
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Hardness, Total [as CaCO3]
The utility reported: 148 ppm
Reported range: 143–153
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
pH
The utility reported: 8.3 units
Reported range: 8.2–8.3
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Potassium
The utility reported: 2.6 ppm
Reported range: 2.6–2.6
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Sodium
The utility reported: 46 ppm
Reported range: 46–46
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Total Organic Carbon [TOC]
The utility reported: 2.4 ppm
Reported range: 2.0–2.5
Typical source, per the report: NA
Reported constituent · report p. PAGE 7 · official report
Aluminum
The utility reported: 62 ppb
Reported range: 52–91
Typical source, per the report: Erosion of natural deposits; Residual from some surface water treatment processes
Reported constituent · report p. PAGE 7 · official report
Chloride
The utility reported: 40 ppm
Reported range: 39–41
Typical source, per the report: Runoff/leaching from natural deposits; Seawater influence
Reported constituent · report p. PAGE 7 · official report
Color
The utility reported: 1 units
Reported range: 1–1
Typical source, per the report: Naturally occurring organic materials
Reported constituent · report p. PAGE 7 · official report
Corrosivity
The utility reported: 12.2 units
Reported range: 12.2–12.2
Typical source, per the report: Natural or industrially influenced balance of hydrogen, carbon, and oxygen affected by temperature and other factors
Reported constituent · report p. PAGE 7 · official report
Specific Conductance
The utility reported: 510 µS/cm
Reported range: 498–522
Typical source, per the report: Substances that form ions when in water; Seawater influence
Reported constituent · report p. PAGE 7 · official report
Sulfate
The utility reported: 90 ppm
Reported range: 89–92
Typical source, per the report: Runoff/leaching from natural deposits; Industrial wastes
Reported constituent · report p. PAGE 7 · official report
Total Dissolved Solids
The utility reported: 306 ppm
Reported range: 291–322
Typical source, per the report: Runoff/leaching from natural deposits
Reported constituent · report p. PAGE 7 · official report
The Three C's — 3 of 3
Corrosion
What conditions could influence pipes, fixtures, and a water heater?
City of Thousand Oaks Water System
Alkalinity, total as CaCO3
The utility reported: 98 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
pH
The utility reported: 8.3 pH units
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Sulfate
The utility reported: 90 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Chloride
The utility reported: 40 ppm
MWD Jensen Plant 98% of Supply · report p. PAGE 5 · official report
Copper
The utility reported: 0.15 ppm
Typical source, per the report: Internal corrosion of household plumbing systems; erosion of natural deposits
Reported constituent · report p. PAGE 4 · official report
California American Water - Thousand Oaks
Alkalinity
The utility reported: 96 - 100 ppm
OTHER SUBSTANCES OF INTEREST · report p. 8 · official report
Lead 90th Percentile
The utility reported: 3.0 ppb
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
Copper 90th Percentile
The utility reported: 0.132 ppm
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
Lead
The utility reported: 3.0 ppb
Reported range: ND to 5.0
Typical source, per the report: Corrosion of household plumbing systems.
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
Copper
The utility reported: 0.132 ppm
Reported range: ND to 0.263
Typical source, per the report: Corrosion of household plumbing systems.
LEAD AND COPPER MONITORING PROGRAM · report p. 3 · official report
CALIFORNIA WATER SERVICE CO - WESTLAKE
Corrosion-related inputs (such as pH or alkalinity) were not itemized in this provider's reviewed report.
Camrosa Water District
Copper
The utility reported: 0.22 ppm
Reported range: 0-0.55
Typical source, per the report: Internal corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives
Reported constituent · report p. PAGE 4 · official report
Lead
The utility reported: 0 ppb
Reported range: 0-5
Typical source, per the report: Internal corrosion of household water plumbing systems; discharges from industrial manufacturers; erosion of natural deposits
Reported constituent · report p. PAGE 4 · official report
Heterotrophic Plate Count Bacteria
The utility reported: Not detected at the report's stated reporting limit CFU/mL
Reported range: ND–2
Typical source, per the report: Naturally present in the environment
Reported constituent · report p. PAGE 5 · official report
Whole-Home Relevance
What this may mean throughout your home
Local conditions can be relevant to equipment and fixtures — actual effects depend on your property.
Water heater (tank and tankless)
- What the local report can tell us
- The report's hardness and mineral values above are the system-level inputs most relevant to scale and sediment where water is heated.
- What a homeowner may notice
- Hardness minerals can contribute to scale on heating surfaces, sediment in tanks, and more frequent flushing or descaling needs.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Dishwasher and washing machine
- What the local report can tell us
- Reported hardness and secondary (aesthetic) records are the relevant system-level context for spotting and residue.
- What a homeowner may notice
- Hard water can change soap behavior and may contribute to spotting on dishes and residue in laundry.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Pipes, fixtures, faucets, and supply lines
- What the local report can tell us
- The corrosion-related inputs above (such as pH) describe the water entering the property — not the condition of any specific plumbing.
- What a homeowner may notice
- Mineral deposits can appear on aerators and fixtures; corrosion outcomes depend on materials, age, and water conditions together.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Drinking and cooking water
- What the local report can tell us
- The contaminant records above show what the utility reported for the system and period, with each benchmark type labeled.
- What a homeowner may notice
- Taste, odor, or aesthetic preferences can be noticeable even when health-based standards are met.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Decision Pathways
Treatment pathways to evaluate
Treatment is a decision pathway, not a product conclusion — no equipment can be responsibly chosen from city-level data alone.
The evaluation sequence we follow, in order:
- 1Define the concern
- 2Verify utility-level and home-specific evidence
- 3Choose point of treatment
- 4Verify the exact certified reduction claim for the exact model
- 5Review tradeoffs and maintenance
Water filtration
- Objective it can address
- Specific substances or aesthetic conditions (taste, odor, chlorine character).
- Point of treatment
- Point of entry or point of use, depending on the objective.
- Limitations to verify
- A filter works only for the conditions and reduction claims its exact design and certification support — filtration does not soften water.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
Water softening
- Objective it can address
- Hardness minerals (calcium and magnesium) and the scale they can contribute to.
- Point of treatment
- Typically point of entry, confirmed by evaluation.
- Limitations to verify
- Softening primarily exchanges hardness minerals — it is not a universal contaminant-removal device.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
Reverse osmosis
- Objective it can address
- Specified dissolved substances at a dedicated outlet, commonly drinking and cooking water.
- Point of treatment
- Typically point of use.
- Limitations to verify
- Produces a reject-water stream and needs pressure and maintenance; verify the exact NSF/ANSI 58 reduction claims for the exact model. It is not automatically the best system for every home.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
When testing is the right next step
Use a certified laboratory when the concern is tap-specific, property-specific, or not resolved by the utility report.
When inspection is the right next step
Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Evidence You Can Check
Official reports, sources, and methodology
Official report — City of Thousand Oaks Water System
2025 Annual Water Quality Report · data year 2024 · 2024 data retained; monitor for the next official update
View the 2024 City of Thousand Oaks Water System Consumer Confidence ReportSource water, per the report: 98% of the City’s water supply was from the State Water Project, imported from Northern California (Lake Oroville), transported via the California Aqueduct, and treated at MWD's Jensen Filtration Plant. The remaining 2% came from the Calleguas Lake Bard Reservoir and Water Filtration Plant.
Official report — California American Water - Thousand Oaks
2025 Annual Water Quality Report Summary · data year 2025 · Current 2025 monitoring cycle
View the 2025 California American Water - Thousand Oaks Consumer Confidence ReportSource water, per the report: The Thousand Oaks/Newbury Park water system is served entirely by treated surface water purchased from the Calleguas Municipal Water District. The Calleguas Municipal Water District is an authorized wholesaler of treated surface water received from the Metropolitan Water District of Southern California’s (MWDSC) Jensen and Weymouth water treatment plants. The sources of the raw surface water are the Sacramento and Colorado Rivers.
Official report — CALIFORNIA WATER SERVICE CO - WESTLAKE
Consumer Confidence Report Certification Form · data year 2024 · 2024 data retained; monitor for the next official update
View the 2024 CALIFORNIA WATER SERVICE CO - WESTLAKE Consumer Confidence ReportOfficial report — Camrosa Water District
Annual Water Quality Report · data year 2024 · 2024 data retained; monitor for the next official update
View the 2024 Camrosa Water District Consumer Confidence ReportSource water, per the report: Camrosa uses a combination of imported and local water. Camrosa Water District operates nine wells in addition to importing water from Calleguas Municipal Water District (a distributor for the Metropolitan Water District of Southern California). In 2024 approximately 55 percent of the water came from these local wells, and the rest was imported. Local sources include GAC Plant, Penny Well, Woodcreek Well, PV Well 2, RMWTP, and Tierra Rejada Well.
Nearby community water profiles
Property-Specific Next Step
Request a Water Quality Evaluation
Request a water-heater and water-quality evaluation tailored to the property, equipment, and homeowner objective.
A property-specific evaluation confirms your goals, provider, tap conditions, plumbing, equipment, installation, and maintenance before any treatment recommendation — this profile alone is never used to prescribe equipment.
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