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Tap water quality report

El Cajon, CA

EPA monitoring detected 9 contaminants across the 1 water supplier serving El Cajon. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

1
water supplier
12,350
people served
9
contaminants found
California rankings Lead in California PFAS in California

What was found in El Cajon's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
6553 µg/L 66%
of the EPA limit 10000 µg/L
Main supplier: Sycuan · 12,350 people · 2019
1/1 SYR4
TTHM
61.89 µg/L 77%
of the EPA limit 80 µg/L
Main supplier: Sycuan · 12,350 people · 2019
1/1 SYR4
Combined Uranium
32 µg/L 107%
of the EPA limit, at the 95th percentile of samples — 30 µg/L
Main supplier: Sycuan · 12,350 people · 2019
1/1 SYR4
Lithium
20 µg/L
No EPA limit set
Main supplier: Sycuan · 12,350 people · 2025
1/1 UCMR-5
Gross Alpha, Excl. Radon And U
12.5 pCi/L 83%
of the EPA limit 15 pCi/L
Main supplier: Sycuan · 12,350 people · 2017
1/1 SYR4
Copper
7.2 µg/L 0.6%
of the EPA limit 1300 µg/L
Main supplier: Sycuan · 12,350 people · 2018
1/1 SYR4
Total Haloacetic Acids (HAA5)
6.72 µg/L 11%
of the EPA limit 60 µg/L
Main supplier: Sycuan · 12,350 people · 2019
1/1 SYR4
Lead
1.3 µg/L 8.7%
of the EPA limit 15 µg/L
Main supplier: Sycuan · 12,350 people · 2018
1/1 SYR4
Lead
0.0030 mg/L 20%
of the EPA limit 0.0150 mg/L
Main supplier: Sycuan · 12,350 people · 2025
1/1 LCR
Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving El Cajon

SupplierPopulation served
Sycuan 12,350

Frequently asked questions about El Cajon tap water

Is El Cajon tap water safe to drink?

EPA testing detected 9 contaminants in the water serving El Cajon. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve El Cajon?

1 public water supplier report drinking-water monitoring for El Cajon, California to the EPA. Each is listed above with its population served.

What contaminants are in El Cajon's water?

The contaminants EPA monitoring detected in El Cajon include Nitrate, TTHM, Combined Uranium, Lithium, Gross Alpha, Excl. Radon And U. The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.