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Tap water quality report

Carlsbad, CA

EPA monitoring detected 22 contaminants across the 2 water suppliers serving Carlsbad. 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.

2
water suppliers
95,158
people served
22
contaminants found
California rankings Lead in California PFAS in California

What was found in Carlsbad'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
Selenium
1900.87 µg/L 3802%
of the EPA limit, at the 95th percentile of samples — 50 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Lead
974 µg/L 6493%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Fluoride
854.4 µg/L 21%
of the EPA limit 4000 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Arsenic
332.624 µg/L 3326%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Gross Beta Particle Activity
320 pCi/L
No EPA limit set
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Thallium, Total
173 µg/L 8650%
of the EPA limit, at the 95th percentile of samples — 2 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Lithium
52.5 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2023
1/2 UCMR-5
TTHM
33 µg/L 41%
of the EPA limit 80 µg/L
Main supplier: CARLSBAD MWD · 95,158 people · 2019
2/2 SYR4
Beryllium, Total
31 µg/L 775%
of the EPA limit, at the 95th percentile of samples — 4 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Chloroform
12 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
Highest in the city: 16.8 µg/L — CARLSBAD DESALINATION PLANT · 0 people · 2019
2/2 SYR4
Dibromochloromethane
12 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
1/2 SYR4
Total Haloacetic Acids (HAA5)
12 µg/L 20%
of the EPA limit 60 µg/L
Main supplier: CARLSBAD MWD · 95,158 people · 2019
2/2 SYR4
Bromodichloromethane
10 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
1/2 SYR4
Bromoform
6.575 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
2/2 SYR4
Monochloroacetic Acid
5.415 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
1/2 SYR4
Dichloroacetic Acid
5.12 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
2/2 SYR4
Combined Uranium
4.54748 µg/L 15%
of the EPA limit 30 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Trichloroacetic Acid
4.475 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
1/2 SYR4
Dibromoacetic Acid
3.5 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
2/2 SYR4
Monobromoacetic Acid
2.52 µg/L
No EPA limit set
Main supplier: CARLSBAD MWD · 95,158 people · 2019
2/2 SYR4
Dichloromethane
1.61 µg/L 32%
of the EPA limit 5 µg/L
Highest in the city: CARLSBAD DESALINATION PLANT · 0 people · 2019
1/2 SYR4
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
Main supplier: CARLSBAD MWD · 95,158 people · 2024
1/2 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 Carlsbad

SupplierPopulation served
CARLSBAD MWD 95,158
CARLSBAD DESALINATION PLANT 0

Frequently asked questions about Carlsbad tap water

Is Carlsbad tap water safe to drink?

EPA testing detected 22 contaminants in the water serving Carlsbad. 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 Carlsbad?

2 public water suppliers report drinking-water monitoring for Carlsbad, California to the EPA. Each is listed above with its population served.

What contaminants are in Carlsbad's water?

The contaminants EPA monitoring detected in Carlsbad include Selenium, Lead, Fluoride, Arsenic, Gross Beta Particle Activity. 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.