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.

Browse 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.

Compliance history

Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.

Maximum contaminant level exceededHealth-based
1 violation on record · most recent Oct 1979
resolved

Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗

Other

Contaminant	Measured	Federal limit	Status
Chlorine Total	2.38 mg/LAverageTapo Canyon Water Treatment Plant	None set	Within the limit
+By source (2)— WWD8 System Wide, Tapo Canyon Water Treatment Plant WWD8 System WideZone avg2.11 mg/Lrange0.5–3.16 mg/L79% of limit Tapo Canyon Water Treatment PlantPlant avg2.38 mg/Lrange1.16–2.8 mg/L70% of limit
Chromium	0.09 ug/LAverageTapo Canyon Water Treatment Plant	None set	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/L0% 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

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
Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances.	5.5 pCi/LAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal limit
+By source (3)— Calleguas Lake Bard Water Filtration Plant, Tapo Canyon Water Treatment Plant, Metropolitan Jensen Plant Calleguas Lake Bard Water Filtration PlantPlant avg5.5 pCi/Lrange5.4–5.6 pCi/L Tapo Canyon Water Treatment PlantPlant avg2.49 pCi/Lrange2.49 pCi/L Metropolitan Jensen PlantPlant avgNot detected pCi/LrangeNot detected pCi/L
RadonA naturally occurring radioactive gas that can dissolve into groundwater.	390.5 pCi/LAverageTapo Canyon Water Treatment Plant	None set	Detected — no federal limit
UraniumA naturally occurring radioactive metal from erosion of natural deposits.	4.2 pCi/LAverageTapo Canyon Water Treatment Plant	20 pCi/LMCL	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 avg4.2 pCi/Lrange4.2 pCi/L Metropolitan Jensen PlantPlant avg2 pCi/Lrange2–3 pCi/L Calleguas Lake Bard Water Filtration PlantPlant avg1.5 pCi/Lrange1.4–1.5 pCi/L

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	None set	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
TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter.	17.7 ug/LAverageWWD8 System Wide	None set	Within the limit
+By source (2)— WWD8 System Wide, Tapo Canyon Water Treatment Plant WWD8 System WideZone avg17.7 ug/Lrange8.6–35 ug/L44% of limit Tapo Canyon Water Treatment PlantPlant avg5.3 ug/L7% of limit
HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter.	6.2 ug/LAverageWWD8 System Wide	None set	Within the limit
+By source (2)— WWD8 System Wide, Tapo Canyon Water Treatment Plant WWD8 System WideZone avg6.2 ug/Lrange0–14 ug/L23% of limit Tapo Canyon Water Treatment 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	Detected — no federal 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/L Tapo Canyon Water Treatment PlantPlant avg57 ug/Lrange57 ug/L Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L

Metals

Contaminant	Measured	Federal limit	Status
ArsenicA naturally occurring element that also enters water from industry and agriculture.	3 ug/LAverageCalleguas Lake Bard Water Filtration Plant	None set	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 avg3 ug/Lrange2–4 ug/L40% of limit Tapo Canyon Water Treatment PlantPlant avg0.96 ug/Lrange0.96 ug/L10% of limit Metropolitan Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
SeleniumA trace element from natural deposits and industrial discharge.	11 ug/LAverageTapo Canyon Water Treatment Plant	None set	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 avg11 ug/Lrange11 ug/L22% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/Lrange0–6 ug/L12% of limit Metropolitan Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
CopperA metal that enters water from corroding household plumbing.	0.11 mg/L90th percentileAt the tap	1.3 mg/LAction level	Within the limit
LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures.	0.001 mg/L90th percentileAt the tap	None set	Within the limit
AluminumA common element sometimes used as a treatment coagulant.	62 ug/LAverageMetropolitan Jensen Plant	None set	Detected — no federal 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/L Tapo Canyon Water Treatment PlantPlant avgNot detected ug/LrangeNot detected ug/L Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L
BoronA naturally occurring element from rock and soil.	0.28 mg/LAverageCalleguas Lake Bard Water Filtration Plant	1 mg/LPublic health goal	Detected — no federal 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/L Tapo Canyon Water Treatment PlantPlant avg0.17 mg/Lrange0.17 mg/L Metropolitan Jensen PlantPlant avg0.17 mg/Lrange0.17 mg/L
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
Vanadium	4.3 ug/LAverageTapo Canyon Water Treatment Plant	50 ug/LPublic health goal	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 avg4.3 ug/Lrange4.3 ug/L Metropolitan Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L Calleguas Lake Bard Water Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L
ZincA naturally occurring metal that can also enter water from corroding pipes.	0.06 mg/LAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal 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/L Tapo Canyon Water Treatment PlantPlant avg0.011 mg/Lrange0.011 mg/L Metropolitan Jensen PlantPlant avgNot detected mg/LrangeNot detected mg/L

Inorganic chemicals

Contaminant	Measured	Federal limit	Status
NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits.	0.69 mg/LAverageTapo Canyon Water Treatment Plant	10 mg/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 avg0.69 mg/Lrange0.69 mg/L7% of limit Metropolitan Jensen PlantPlant avg0.5 mg/Lrange0.5 mg/L5% of limit Calleguas Lake Bard Water Filtration PlantPlant avgNot detected mg/LrangeNot detected mg/L0% of limit
FluorideA mineral often added to drinking water to help prevent tooth decay.	Not detected mg/LRangeTapo Canyon Water Treatment Plant	4 mg/LMCL	None detected
ChlorideA naturally occurring salt compound.	99 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 avg99 mg/Lrange99–100 mg/L Metropolitan Jensen PlantPlant avg40 mg/Lrange39–41 mg/L Tapo Canyon Water Treatment PlantPlant avg19 mg/Lrange19 mg/L
SulfateA naturally occurring mineral from rock and soil.	125 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 avg125 mg/Lrange120–130 mg/L Calleguas Lake Bard Water Filtration PlantPlant avg103 mg/Lrange102–103 mg/L Metropolitan Jensen PlantPlant avg90 mg/Lrange89–92 mg/L

Microbial

Contaminant	Measured	Federal limit	Status
Total ColiformA group of bacteria used as an indicator of overall water-system sanitation.	0 %MaximumSystem-wide	None set	None detected

Physical & aggregate

Contaminant	Measured	Federal limit	Status
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
ColorA measure of visible tint in the water.	1 %AverageMetropolitan Jensen Plant	None set	Detected — no federal limit
+By source (3)— Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant Metropolitan Jensen PlantPlant avg1 %range1 % Tapo Canyon Water Treatment PlantPlant avgNot detected %rangeNot detected % Calleguas Lake Bard Water Filtration PlantPlant avgNot detected %rangeNot detected %
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
OdorA measure of detectable smell in the water.	1 %AverageMetropolitan Jensen Plant	None set	Detected — no federal limit
+By source (3)— Metropolitan Jensen Plant, Tapo Canyon Water Treatment Plant, Calleguas Lake Bard Water Filtration Plant Metropolitan Jensen PlantPlant avg1 %range1 % Tapo Canyon Water Treatment PlantPlant avgNot detected %rangeNot detected % Calleguas Lake Bard Water Filtration PlantPlant avgNot detected %rangeNot detected %
pHA measure of how acidic or basic the water is.	8.3 %AverageMetropolitan Jensen Plant	None set	Detected — no federal limit
+By source (3)— Metropolitan Jensen Plant, Calleguas Lake Bard Water Filtration Plant, Tapo Canyon Water Treatment Plant Metropolitan Jensen PlantPlant avg8.3 %range8.2–8.3 % Calleguas Lake Bard Water Filtration PlantPlant avg8.2 %range8.1–8.3 % Tapo Canyon Water Treatment PlantPlant avg7.3 %range6.8–7.8 %
Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content.	782 %AverageCalleguas Lake Bard Water Filtration 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 avg543 %range510–1100 % Calleguas Lake Bard Water Filtration PlantPlant avg782 %range773–790 % Metropolitan Jensen PlantPlant avg510 %range498–522 %
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
Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts.	430 mg/LAverageCalleguas Lake Bard Water Filtration Plant	None set	Detected — no federal 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/L Tapo Canyon Water Treatment PlantPlant avg344.4 mg/Lrange320–390 mg/L Metropolitan Jensen PlantPlant avg306 mg/Lrange291–322 mg/L
TurbidityA measure of cloudiness from suspended particles in the water.	0.14 %AverageCalleguas 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 % Metropolitan Jensen PlantPlant avg0.04 % Tapo Canyon Water Treatment PlantPlant avgNot detected %

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.