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Tap water quality report

San Antonio, MP

EPA monitoring detected 13 contaminants across the 3 water suppliers serving San Antonio. 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.

3
water suppliers
848
people served
13
contaminants found
MP rankings Lead in MP PFAS in MP

What was found in San Antonio'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
2500 µg/L 25%
of the EPA limit 10000 µg/L
Highest in the city: Aqua Water · 170 people · 2017
2/3 SYR4
Fluoride
750 µg/L 19%
of the EPA limit 4000 µg/L
Highest in the city: Winners Residence · 124 people · 2017
1/3 SYR4
TTHM
0.5700 µg/L 0.7%
of the EPA limit 80 µg/L
Main supplier: Pacific Islands Club · 554 people · 2019
Highest in the city: 20 µg/L — Winners Residence · 124 people · 2019
2/3 SYR4
Selenium
7.9 µg/L 16%
of the EPA limit 50 µg/L
Highest in the city: Winners Residence · 124 people · 2017
1/3 SYR4
Total Haloacetic Acids (HAA5)
4.7 µg/L 7.8%
of the EPA limit 60 µg/L
Highest in the city: Winners Residence · 124 people · 2019
1/3 SYR4
Barium
4.4 µg/L 0.2%
of the EPA limit 2000 µg/L
Highest in the city: Winners Residence · 124 people · 2017
1/3 SYR4
Arsenic
2.8 µg/L 28%
of the EPA limit 10 µg/L
Highest in the city: Winners Residence · 124 people · 2017
1/3 SYR4
Combined Uranium
1.53843 µg/L 5.1%
of the EPA limit 30 µg/L
Main supplier: Pacific Islands Club · 554 people · 2017
Highest in the city: 2.1903 µg/L — Aqua Water · 170 people · 2017
2/3 SYR4
Antimony, Total
1.1 µg/L 18%
of the EPA limit 6 µg/L
Highest in the city: Winners Residence · 124 people · 2017
1/3 SYR4
cis-1,2-Dichloroethylene
1.1 µg/L 1.6%
of the EPA limit 70 µg/L
Highest in the city: Winners Residence · 124 people · 2017
1/3 SYR4
Gross Alpha, Excl. Radon And U
1.0325 pCi/L 6.9%
of the EPA limit 15 pCi/L
Main supplier: Pacific Islands Club · 554 people · 2017
2/3 SYR4
Combined Radium (-226 And -228)
0.7200 pCi/L 14%
of the EPA limit 5 pCi/L
Main supplier: Pacific Islands Club · 554 people · 2017
2/3 SYR4
Lead
0.00060 mg/L 4%
of the EPA limit 0.0150 mg/L
Main supplier: Pacific Islands Club · 554 people · 2025
Highest in the city: 0.0540 mg/L — Winners Residence · 124 people · 2025
3/3 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 San Antonio

SupplierPopulation served
Pacific Islands Club 554
Aqua Water 170
Winners Residence 124

Frequently asked questions about San Antonio tap water

Is San Antonio tap water safe to drink?

EPA testing detected 13 contaminants in the water serving San Antonio. 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 San Antonio?

3 public water suppliers report drinking-water monitoring for San Antonio, MP to the EPA. Each is listed above with its population served.

What contaminants are in San Antonio's water?

The contaminants EPA monitoring detected in San Antonio include Nitrate, Fluoride, TTHM, Selenium, Total Haloacetic Acids (HAA5). 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.