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Tap water quality report

San Carlos, AZ

EPA monitoring detected 13 contaminants across the 7 water suppliers serving San Carlos. 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.

7
water suppliers
11,217
people served
13
contaminants found
Arizona rankings Lead in Arizona PFAS in Arizona

What was found in San Carlos'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
2648.5 µg/L 26%
of the EPA limit 10000 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2019
Highest in the city: 3640 µg/L — SCUA Lower Peridot Bush · 342 people · 2018
6/7 SYR4
Fluoride
497 µg/L 12%
of the EPA limit 4000 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2015
Highest in the city: 520 µg/L — SCUA Upper Peridot · 275 people · 2012
5/7 SYR4
Nitrite
100 µg/L 10%
of the EPA limit 1000 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2019
1/7 SYR4
Barium
90 µg/L 4.5%
of the EPA limit 2000 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2015
5/7 SYR4
Lithium
72.8 µg/L
No EPA limit set
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2025
1/7 UCMR-5
Arsenic
14.88 µg/L 149%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2019
6/7 SYR4
Chromium
10 µg/L 10%
of the EPA limit 100 µg/L
Highest in the city: SCUA Skill Center · 234 people · 2012
1/7 SYR4
TTHM
5.8 µg/L 7.2%
of the EPA limit 80 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2019
2/7 SYR4
Combined Uranium
5.5726 µg/L 19%
of the EPA limit 30 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2018
3/7 SYR4
Gross Alpha, Excl. Radon And U
3.765 pCi/L 25%
of the EPA limit 15 pCi/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2018
3/7 SYR4
Selenium
2 µg/L 4%
of the EPA limit 50 µg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2015
5/7 SYR4
PFBS
0.0538 µg/L
No EPA limit set
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2025
1/7 UCMR-5
Lead
0.0050 mg/L 33%
of the EPA limit 0.0150 mg/L
Main supplier: SCUA Upper Seven Mile · 8,478 people · 2025
7/7 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 Carlos

SupplierPopulation served
SCUA Upper Seven Mile 8,478
SCUA Lower Peridot 702
SCUA Beverly Hills 612
SCUA Cutter 574
SCUA Lower Peridot Bush 342
SCUA Upper Peridot 275
SCUA Skill Center 234

Frequently asked questions about San Carlos tap water

Is San Carlos tap water safe to drink?

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

7 public water suppliers report drinking-water monitoring for San Carlos, Arizona to the EPA. Each is listed above with its population served.

What contaminants are in San Carlos's water?

The contaminants EPA monitoring detected in San Carlos include Nitrate, Fluoride, Nitrite, Barium, Lithium. 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.