What's in Simi Valley, CA tap water

36 contaminants were measured in the Simi Valley, CA water system's 2024 annual report. Each is shown below against its federal limit.

See it on the mapFull source report ↗

Reporting year: 2024
Contaminants measured: 36
Over federal limit: 0
Approaching the limit: 0
Service area: CA
Source: Utility CCR

All within federal limits. Every measured contaminant in this report is below its federal threshold.

Where your water comes from · EPA SDWIS

Simi Valley, CA's drinking water comes from ground water, drawn from 3 sources.

Source

3ground water

WELL · 3

Treatment

1treatment plant

TAPO CANYON MEMBRANE TP

Distribution

0storage units

Also buys water from CALLEGUAS MUNICIPAL WATER DIST.

Source: EPA SDWIS facilities inventory. Methodology.

Historical readings · EPA Six-Year Review (2012–2019)

20 historically-detected contaminants in Simi Valley, CA

About this data

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)
GROSS BETA worst: 2015	3.4 mrem/yr 85%	4 mrem/yr	'15'17'18
TTHM worst: 2013	0.063 mg/L within	0.08 mg/L	'12'13'14'15'16'17'18'19
SELENIUM worst: 2018	0.039 mg/L within	0.05 mg/L	'12'14'15'17'18
ARSENIC worst: 2018	0.0041 mg/L within below national p90	0.01 mg/L	'12'15'17'18
HAA5 worst: 2018	0.018 mg/L within	0.06 mg/L	'12'13'14'15'16'17'18'19
NITRATE worst: 2012	2.71 mg/L within	10 mg/L	'12'13'14'15'16'17'18'19
NITRATE NITRITE worst: 2017	1.4 mg/L within	10 mg/L	'17'18'19
FLUORIDE worst: 2014	0.38 mg/L within	4 mg/L	'12'14'15'17'18
BARIUM worst: 2019	0.12 mg/L within near national p90	2 mg/L	'19
URANIUM worst: 2019	0.0179 ug/L within near national p90	30 ug/L	'12'14'15'17'18'19
COPPER worst: 2017	0.1 mg/L below national p90	—	'17'18
DBAA worst: 2012	0.0048 mg/L	—	'12'13'14'15'16'17'18'19
DCAA worst: 2012	0.0025 mg/L	—	'12'13'14'15'16'17'18'19
MBAA worst: 2013	0.003 mg/L	—	'13
MCAA worst: 2018	0.0093 mg/L	—	'18
TCAA worst: 2013	0.0022 mg/L	—	'13'14'15'18'19
BROMODICHLOROMETHANE worst: 2012	0.0039 mg/L	—	'12'13'14'15'16'17'18'19
BROMOFORM worst: 2012	0.0074 mg/L	—	'12'13'14'15'16'17'18'19
CHLOROFORM worst: 2012	0.0022 mg/L	—	'12'13'14'15'16'17'18'19
DIBROMOCHLOROMETHANE worst: 2012	0.0095 mg/L	—	'12'13'14'15'16'17'18'19

PWSID CA5610023 · 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.

Physical & aggregate

Contaminant	Measured	Federal limit	Status
Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content.	782 %AverageCalleguas Lake Bard Water Filtration Plant	1600 %MCL	Within the limit
+By source (3)— Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant Tapo Canyon Water Treatment PlantPlant avg543 %range510–1100 %69% of limit Calleguas Lake Bard Water Filtration PlantPlant avg782 %range773–790 %49% of limit Metropolitan Jensen PlantPlant avg510 %range498–522 %33% of limit
Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts.	430 mg/LAverageCalleguas Lake Bard Water Filtration Plant	1000 mg/LMCL	Within the limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant Calleguas Lake Bard Water Filtration PlantPlant avg430 mg/Lrange410–450 mg/L45% of limit Tapo Canyon Water Treatment PlantPlant avg344.4 mg/Lrange320–390 mg/L39% of limit Metropolitan Jensen PlantPlant avg306 mg/Lrange291–322 mg/L32% of limit
OdorA measure of detectable smell in the water.	1 %AverageMetropolitan Jensen Plant	3 %MCL	Within the limit
+By source (3)— Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant Metropolitan Jensen PlantPlant avg1 %range1 %33% of limit Tapo Canyon Water Treatment PlantPlant avgNot detected %rangeNot detected %0% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected %rangeNot detected %0% of limit
ColorA measure of visible tint in the water.	1 %AverageMetropolitan Jensen Plant	15 %MCL	Within the limit
+By source (3)— Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant Metropolitan Jensen PlantPlant avg1 %range1 %7% of limit Tapo Canyon Water Treatment PlantPlant avgNot detected %rangeNot detected %0% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected %rangeNot detected %0% of limit
AlkalinityA measure of the water's capacity to neutralize acids.	140 mg/LAverageTapo Canyon Water Treatment Plant	None set	Detected — no federal limit
+By source (3)— Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant Tapo Canyon Water Treatment PlantPlant avg140 mg/Lrange130–160 mg/L Calleguas Lake Bard Water Filtration PlantPlant avg125 mg/Lrange120–130 mg/L Metropolitan Jensen PlantPlant avg98 mg/Lrange94–101 mg/L
HardnessA measure of dissolved calcium and magnesium minerals.	195 mg/LAverageTapo Canyon Water Treatment Plant	None set	Detected — no federal limit
+By source (3)— Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant Tapo Canyon Water Treatment PlantPlant avg195 mg/Lrange182–207 mg/L Calleguas Lake Bard Water Filtration PlantPlant avg163 mg/Lrange160–165 mg/L Metropolitan Jensen PlantPlant avg148 mg/Lrange143–153 mg/L
pHA measure of how acidic or basic the water is.	8.3 %AverageMetropolitan Jensen Plant	None set	Detected — no federal limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant Calleguas Lake Bard Water Filtration PlantPlant avg8.2 %range8.1–8.3 % Metropolitan Jensen PlantPlant avg8.3 %range8.2–8.3 % Tapo Canyon Water Treatment PlantPlant avg7.3 %range6.8–7.8 %
TOCTotal organic carbon — a measure of organic material dissolved in the water.	2.7 mg/LAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant Calleguas Lake Bard Water Filtration PlantPlant avg2.7 mg/Lrange2.6–2.8 mg/L Metropolitan Jensen PlantPlant avg2.4 mg/Lrange2–2.5 mg/L Tapo Canyon Water Treatment PlantPlant avg0.57 mg/Lrange0.57 mg/L
TurbidityA measure of cloudiness from suspended particles in the water.	0.14 NTUAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant Calleguas Lake Bard Water Filtration PlantPlant avg0.14 NTU Metropolitan Jensen PlantPlant avg0.04 NTU Tapo Canyon Water Treatment PlantPlant avgNot detected NTU

Radionuclides

Contaminant	Measured	Federal limit	Status
Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances.	5.62 pCi/LAverageTapo Canyon Water Treatment Plant	15 pCi/LMCL	Within the limit
+By source (3)— Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant, Calleguas Lake Bard Water Filtration Plant Tapo Canyon Water Treatment PlantPlant avg5.62 pCi/Lrange5.62 pCi/L37% of limit Metropolitan Jensen PlantPlant avgNot detected pCi/LrangeNot detected pCi/L0% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected pCi/LrangeNot detected pCi/L0% of limit
RadonA naturally occurring radioactive gas that can dissolve into groundwater.	390.5 pCi/LAverageTapo Canyon Water Treatment Plant	None set	Detected — no federal limit

Disinfection byproducts

Contaminant	Measured	Federal limit	Status
BromateA disinfection byproduct formed when bromide-containing water is treated with ozone.	3.1 ug/LAverageMetropolitan Jensen Plant	10 ug/LMCL	Within the limit
+By source (3)— Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant Metropolitan Jensen PlantPlant avg3.1 ug/Lrange0–5.4 ug/L54% of limit Tapo Canyon Water Treatment PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade.	71 ug/LAverageMetropolitan Jensen Plant	800 ug/LPublic health goal	Within the limit
+By source (3)— Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant Metropolitan Jensen PlantPlant avg71 ug/Lrange71 ug/L9% of limit Tapo Canyon Water Treatment PlantPlant avg57 ug/Lrange57 ug/L7% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit

Metals

Contaminant	Measured	Federal limit	Status
AluminumA common element sometimes used as a treatment coagulant.	62 ug/LAverageMetropolitan Jensen Plant	200 ug/LMCL	Within the limit
+By source (3)— Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant Metropolitan Jensen PlantPlant avg62 ug/Lrange52–91 ug/L9% of limit Tapo Canyon Water Treatment PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
BoronA naturally occurring element from rock and soil.	0.28 mg/LAverageCalleguas Lake Bard Water Filtration Plant	1 mg/LPublic health goal	Within the limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant Calleguas Lake Bard Water Filtration PlantPlant avg0.28 mg/Lrange0.27–0.28 mg/L28% of limit Tapo Canyon Water Treatment PlantPlant avg0.17 mg/Lrange0.17 mg/L17% of limit Metropolitan Jensen PlantPlant avg0.17 mg/Lrange0.17 mg/L17% of limit
Vanadium	4.3 ug/LAverageTapo Canyon Water Treatment Plant	50 ug/LPublic health goal	Within the limit
+By source (3)— Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant, Calleguas Lake Bard Water Filtration Plant Tapo Canyon Water Treatment PlantPlant avg4.3 ug/Lrange4.3 ug/L9% of limit Metropolitan Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
ZincA naturally occurring metal that can also enter water from corroding pipes.	0.06 mg/LAverageCalleguas Lake Bard Water Filtration Plant	5 mg/LMCL	Within the limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant Calleguas Lake Bard Water Filtration PlantPlant avg0.06 mg/Lrange0.06 mg/L1% of limit Tapo Canyon Water Treatment PlantPlant avg0.011 mg/Lrange0.011 mg/L0% of limit Metropolitan Jensen PlantPlant avgNot detected mg/LrangeNot detected mg/L0% of limit
Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge.	0.09 ug/LAverageTapo Canyon Water Treatment Plant	10 ug/LMCL	Within the limit
+By source (3)— Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant, Calleguas Lake Bard Water Filtration Plant Tapo Canyon Water Treatment PlantPlant avg0.09 ug/Lrange0.044–0.18 ug/L2% of limit Metropolitan Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures.	0.001 mg/L90th percentileAt the tap	15 mg/LAction level	Within the limit
CalciumA naturally occurring mineral that contributes to water hardness.	58 mg/LAverageTapo Canyon Water Treatment Plant	None set	Detected — no federal limit
+By source (3)— Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant, Calleguas Lake Bard Water Filtration Plant Tapo Canyon Water Treatment PlantPlant avg58 mg/Lrange54–61 mg/L Metropolitan Jensen PlantPlant avg38 mg/Lrange38–39 mg/L Calleguas Lake Bard Water Filtration PlantPlant avg37 mg/Lrange36–38 mg/L
MagnesiumA naturally occurring mineral that contributes to water hardness.	17 mg/LAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant Calleguas Lake Bard Water Filtration PlantPlant avg17 mg/Lrange17 mg/L Metropolitan Jensen PlantPlant avg14 mg/Lrange13–14 mg/L Tapo Canyon Water Treatment PlantPlant avg12.2 mg/Lrange11.4–13 mg/L
PotassiumA naturally occurring mineral from rock and soil.	4 mg/LAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant Calleguas Lake Bard Water Filtration PlantPlant avg4 mg/Lrange4 mg/L Metropolitan Jensen PlantPlant avg2.6 mg/Lrange2.6 mg/L Tapo Canyon Water Treatment PlantPlant avg1.4 mg/Lrange1.4 mg/L
SodiumA naturally occurring salt component.	89 mg/LAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant Calleguas Lake Bard Water Filtration PlantPlant avg89 mg/Lrange86–91 mg/L Metropolitan Jensen PlantPlant avg46 mg/Lrange46 mg/L Tapo Canyon Water Treatment PlantPlant avg35 mg/Lrange35 mg/L

Inorganic chemicals

Contaminant	Measured	Federal limit	Status
SulfateA naturally occurring mineral from rock and soil.	125 mg/LAverageTapo Canyon Water Treatment Plant	500 mg/LMCL	Within the limit
+By source (3)— Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant Tapo Canyon Water Treatment PlantPlant avg125 mg/Lrange120–130 mg/L26% of limit Calleguas Lake Bard Water Filtration PlantPlant avg103 mg/Lrange102–103 mg/L21% of limit Metropolitan Jensen PlantPlant avg90 mg/Lrange89–92 mg/L18% of limit
ChlorideA naturally occurring salt compound.	99 mg/LAverageCalleguas Lake Bard Water Filtration Plant	500 mg/LMCL	Within the limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant Calleguas Lake Bard Water Filtration PlantPlant avg99 mg/Lrange99–100 mg/L20% of limit Metropolitan Jensen PlantPlant avg40 mg/Lrange39–41 mg/L8% of limit Tapo Canyon Water Treatment PlantPlant avg19 mg/Lrange19 mg/L4% of limit

Microbial

Contaminant	Measured	Federal limit	Status
Total ColiformA group of bacteria used as an indicator of overall water-system sanitation.	0 %Highest single sampleSystem-wide	5 %MCL	None detected

Disinfectants

Contaminant	Measured	Federal limit	Status
ChlorineA disinfectant added to drinking water to kill bacteria and viruses.	2.3–2.8 mg/LAverageMetropolitan Jensen Plant	None set	Detected — no federal limit
+By source (3)— WWD8 System Wide, Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant WWD8 System WideZone avg2.11 mg/Lrange0.5–3.16 mg/L Tapo Canyon Water Treatment PlantPlant avg2.38 mg/Lrange1.16–2.8 mg/L Metropolitan Jensen PlantPlant avg2.3–2.8 mg/L

Source: Simi Valley, 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.