Is Tonto Basin, AZ Tap Water Safe? Quality & Contaminants

What was found in Tonto Basin'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.

Contaminant	Level vs EPA limit	Suppliers	Source
Nitrate	631.5 µg/L 6.3% of the EPA limit 10000 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2019 Highest in the city: 1200 µg/L — LAKE ROOSEVELT GARDENS EAST · 121 people · 2019	2/2	SYR4
Nitrate-Nitrite	636 µg/L 6.4% of the EPA limit 10000 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2013	2/2	SYR4
Copper	287.5 µg/L 22% of the EPA limit 1300 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2017 Highest in the city: 569 µg/L — LAKE ROOSEVELT GARDENS EAST · 121 people · 2019	2/2	SYR4
Fluoride	520 µg/L 13% of the EPA limit 4000 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2013	2/2	SYR4
Nitrite	290 µg/L 29% of the EPA limit 1000 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2013	1/2	SYR4
Barium	42 µg/L 2.1% of the EPA limit 2000 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2013 Highest in the city: 68 µg/L — LAKE ROOSEVELT GARDENS EAST · 121 people · 2013	2/2	SYR4
Lead	15.145 µg/L 101% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2017 Highest in the city: 25.725 µg/L — LAKE ROOSEVELT GARDENS EAST · 121 people · 2019	2/2	SYR4
TTHM	7.335 µg/L 9.2% of the EPA limit 80 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2018	2/2	SYR4
Arsenic	2.6 µg/L 26% of the EPA limit 10 µg/L Main supplier: NORTH BAY ESTATES · 156 people · 2013 Highest in the city: 2.8 µg/L — LAKE ROOSEVELT GARDENS EAST · 121 people · 2013	2/2	SYR4
Total Haloacetic Acids (HAA5)	2.7 µg/L 4.5% of the EPA limit 60 µg/L Highest in the city: LAKE ROOSEVELT GARDENS EAST · 121 people · 2018	1/2	SYR4
Lead	0.0055 mg/L 37% of the EPA limit 0.0150 mg/L Main supplier: NORTH BAY ESTATES · 156 people · 2026	2/2	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 Tonto Basin

Supplier	Population served
NORTH BAY ESTATES	156
LAKE ROOSEVELT GARDENS EAST	121

Frequently asked questions about Tonto Basin tap water

Is Tonto Basin tap water safe to drink?

EPA testing detected 11 contaminants in the water serving Tonto Basin. 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 Tonto Basin?

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

What contaminants are in Tonto Basin's water?

The contaminants EPA monitoring detected in Tonto Basin include Nitrate, Nitrate-Nitrite, Copper, Fluoride, Nitrite. 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.