What's in El Cajon, CA tap water

45 contaminants were measured in the El Cajon, CA water system's 2024 annual report. Each is shown below against its federal limit — 3 sit at or above that limit.

See it on the mapFull source report ↗

Reporting year: 2024
Contaminants measured: 45
Over federal limit: 3
Approaching the limit: 0
Worst contaminant: Specific Conductance
Service area: CA
Source: Utility CCR

At or above the federal limit

Where your water comes from · EPA SDWIS

El Cajon, CA buys its drinking water from IMPERIAL IRRIGATION DISTRICT.

Source

0sources

Treatment

1treatment plant

TREATMENT PLANT EFFLUENT

Distribution

0storage units

Also buys water from IMPERIAL IRRIGATION DISTRICT.

Source: EPA SDWIS facilities inventory. Methodology.

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

11 historically-detected contaminants in El Cajon, 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)
TTHM worst: 2017	0.07 mg/L 88%	0.08 mg/L	'13'14'15'16'17'18'19
HAA5 worst: 2016	0.029 mg/L within	0.06 mg/L	'13'14'15'16'17'18'19
TCAA worst: 2013	0.0018 mg/L	—	'13'16'17
DBAA worst: 2013	0.0052 mg/L	—	'13'14'15'16'17'18'19
DCAA worst: 2013	0.0043 mg/L	—	'13'14'15'16'17'18'19
MCAA worst: 2014	0.005 mg/L	—	'14'15'16
MBAA worst: 2013	0.0011 mg/L	—	'13'14'15'16'18
BROMODICHLOROMETHANE worst: 2013	0.02 mg/L	—	'13'14'15'16'17'18'19
BROMOFORM worst: 2013	0.0099 mg/L	—	'13'14'15'16'17'18'19
CHLOROFORM worst: 2013	0.01 mg/L	—	'13'14'15'16'17'18'19
DIBROMOCHLOROMETHANE worst: 2013	0.021 mg/L	—	'13'14'15'16'17'18'19

PWSID CA1310700 · 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.	800AverageHelix Plant	1MCL	At or above the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg72391700% of limit Helix PlantPlant avg80083000% of limit
Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts.	483 mg/LAverageHelix Plant	1 mg/LMCL	At or above the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg450 mg/L61400% of limit Helix PlantPlant avg483 mg/L50000% of limit
TurbidityA measure of cloudiness from suspended particles in the water.	0.09 NTUAverageHelix Plant	5 NTUMCL	Within the limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avg0.05 NTU18% of limit Purchased WaterPlant
AlkalinityA measure of the water's capacity to neutralize acids.	118 mg/LAverageHelix Plant	None set	Detected — no federal limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avg118 mg/L Purchased WaterPlant avg94 mg/L
HardnessA measure of dissolved calcium and magnesium minerals.	214 mg/LAverageHelix Plant	None set	Detected — no federal limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg9.1 mg/L Helix PlantPlant avg214 mg/L
pHA measure of how acidic or basic the water is.	8.3AveragePurchased Water	None set	Detected — no federal limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg8.3 Helix PlantPlant avg8.3
TOCTotal organic carbon — a measure of organic material dissolved in the water.	2.6 mg/LAverageHelix Plant	None set	Detected — no federal limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avg2.6 mg/L Purchased WaterPlant avg2.4 mg/L

Metals

Contaminant	Measured	Federal limit	Status
LithiumA naturally occurring element found in some groundwater.	28 ug/LAveragePurchased Water	10 ug/LNL	At or above the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg28 ug/L320% of limit Helix PlantPlant avg25 ug/L260% of limit
AluminumA common element sometimes used as a treatment coagulant.	140AverageHelix Plant	200MCL	Within the limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avg140115% of limit Purchased WaterPlant avg6380% of limit
BoronA naturally occurring element from rock and soil.	0.39 mg/LAveragePurchased Water	1 mg/LNL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg0.39 mg/L92% of limit Helix PlantPlant avgNot detected mg/L11% of limit
ArsenicA naturally occurring element that also enters water from industry and agriculture.	2.3 ug/LAverageHelix Plant	10 ug/LMCL	Within the limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avg2.3 ug/L49% of limit Purchased WaterPlant avgNot detected ug/L0% of limit
CopperA metal that enters water from corroding household plumbing.	0.054 mg/L90th percentileAt the tap	1.3 mg/LAction level	Within the limit
+By source (3)— Number of Sites Sampled, Helix Plant, Purchased Water Number of Sites SampledPlant 5308% of limit Helix PlantPlant avgNot detected mg/L0% of limit Purchased WaterPlant avgNot detected mg/L0% of limit
BariumA metal from erosion of natural deposits and industrial discharge.	Not detected mg/LAveragePurchased Water	1 mg/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avgNot detected mg/L12% of limit Helix PlantPlant avgNot detected mg/L0% of limit
LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures.	Not detected ug/L90th percentileAt the tap	15 ug/LAction level	Within the limit
Vanadium	Not detected ug/LAveragePurchased Water	50 ug/LNL	Within the limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avgNot detected ug/L9% of limit Purchased WaterPlant avgNot detected ug/L0% of limit
CalciumA naturally occurring mineral that contributes to water hardness.	51 mg/LAverageHelix Plant	None set	Detected — no federal limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg43 mg/L Helix PlantPlant avg51 mg/L
Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium.	Not detected ug/LAverageHelix Plant	None set	Detected — no federal limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avgNot detected ug/L Helix PlantPlant avgNot detected ug/L
MagnesiumA naturally occurring mineral that contributes to water hardness.	21 mg/LAverageHelix Plant	None set	Detected — no federal limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avg21 mg/L Purchased WaterPlant avg12 mg/L
PotassiumA naturally occurring mineral from rock and soil.	6 mg/LAveragePurchased Water	None set	Detected — no federal limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg6 mg/L Helix PlantPlant avg4.5 mg/L
SilicaA naturally occurring compound from sand and rock.	9.7 mg/LAverageHelix Plant	None set	Detected — no federal limit
SodiumA naturally occurring salt component.	76 mg/LAverageHelix Plant	None set	Detected — no federal limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg75 mg/L Helix PlantPlant avg76 mg/L
Strontium	0.86 mg/LAverageHelix Plant	None set	Detected — no federal limit

Inorganic chemicals

Contaminant	Measured	Federal limit	Status
FluorideA mineral often added to drinking water to help prevent tooth decay.	0.7 mg/LAverageHelix Plant	2 mg/LMCL	Within the limit
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avg0.7 mg/L45% of limit Purchased WaterPlant avg0.7 mg/L40% of limit
SulfateA naturally occurring mineral from rock and soil.	140 mg/LAverageHelix Plant	500 mg/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg135 mg/L43% of limit Helix PlantPlant avg140 mg/L30% of limit
ChlorideA naturally occurring salt compound.	88 mg/LAveragePurchased Water	500 mg/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg88 mg/L22% of limit Helix PlantPlant avg86 mg/L18% of limit
NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits.	Not detected mg/LAverageHelix Plant	10 mg/LMCL	None detected
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avgNot detected mg/L0% of limit Purchased WaterPlant avgNot detected mg/L0% of limit
BromideA naturally occurring salt found in source water.	Not detected mg/LAverageHelix Plant	None set	Detected — no federal limit

Disinfection byproducts

Contaminant	Measured	Federal limit	Status
ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade.	186 ug/LAveragePurchased Water	800 ug/LNL	Within the limit
BromateA disinfection byproduct formed when bromide-containing water is treated with ozone.	1.6 ug/LAveragePurchased Water	10 ug/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg1.6 ug/L85% of limit Helix PlantPlant avgNot detected ug/L0% of limit
NDMA	Not detected ng/LAverageHelix Plant	10 ng/LNL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avgNot detected ng/L25% of limit Helix PlantPlant avgNot detected ng/L0% of limit

Microbial

Contaminant	Measured	Federal limit	Status
Total ColiformA group of bacteria used as an indicator of overall water-system sanitation.	0.6 %MaximumHelix Plant	5 %MCL	Within the limit
Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals.	0 %MinimumHelix Plant	0 %MCL	None detected

Radionuclides

Contaminant	Measured	Federal limit	Status
UraniumA naturally occurring radioactive metal from erosion of natural deposits.	1.4 pCi/LAveragePurchased Water	20 pCi/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg1.4 pCi/L15% of limit Helix PlantPlant avg1.3 pCi/L13% of limit
Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances.	2.7 pCi/LAveragePurchased Water	50 pCi/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg2.7 pCi/L10% of limit Helix PlantPlant avgNot detected pCi/L0% of limit
Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements.	0.16 pCi/LAveragePurchased Water	5 pCi/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avg0.16 pCi/L19% of limit Helix PlantPlant avgNot detected pCi/L0% of limit
Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances.	Not detected pCi/LAverageHelix Plant	15 pCi/LMCL	Within the limit
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avgNot detected pCi/L27% of limit Helix PlantPlant avgNot detected pCi/L25% of limit

PFAS ("forever chemicals")

Contaminant	Measured	Federal limit	Status
Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound.	Not detected ng/LMinimumHelix Plant	None set	None detected
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avgNot detected ng/L Purchased WaterPlant avgNot detected ng/L
Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.'	Not detected ng/LAverageHelix Plant	500 ng/LNL	None detected
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avgNot detected ng/L0% of limit Purchased WaterPlant avgNot detected ng/L0% of limit
Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.'	Not detected ng/LMaximumPurchased Water	3 ng/LNL	None detected
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avgNot detected ng/L0% of limit Helix PlantPlant avgNot detected ng/L0% of limit
Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.'	Not detected ng/LAveragePurchased Water	None set	None detected
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avgNot detected ng/L Helix PlantPlant avgNot detected ng/L
PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products.	Not detected ng/LMinimumPurchased Water	5.1 ng/LNL	None detected
+By source (2)— Purchased Water, Helix Plant Purchased WaterPlant avgNot detected ng/L0% of limit Helix PlantPlant avgNot detected ng/L0% of limit
PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings.	Not detected ng/LMinimumHelix Plant	6.5 ng/LNL	None detected
+By source (2)— Helix Plant, Purchased Water Helix PlantPlant avgNot detected ng/L0% of limit Purchased WaterPlant avgNot detected ng/L0% of limit

Disinfectants

Contaminant	Measured	Federal limit	Status
ChloramineA longer-lasting disinfectant made by combining chlorine with ammonia.	1.9 mg/LAverageHelix Plant	None set	Detected — no federal limit

Source: El Cajon, 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.