Tap WaterIndex

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Tap water quality report

Ontario, NY

EPA monitoring detected 19 contaminants across the 1 water supplier serving Ontario. 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
10,136
people served
19
contaminants found
New York rankings Lead in New York PFAS in New York

What was found in Ontario'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
Fluoride
1000 µg/L 25%
of the EPA limit 4000 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Nitrate
540 µg/L 5.4%
of the EPA limit 10000 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Nitrate-Nitrite
449 µg/L 4.5%
of the EPA limit 10000 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2016
1/1 SYR4
TTHM
55 µg/L 69%
of the EPA limit 80 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Chloroform
29 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
23 µg/L 38%
of the EPA limit 60 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Barium
22.65 µg/L 1.1%
of the EPA limit 2000 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Bromodichloromethane
17 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Dichloroacetic Acid
11.45 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Trichloroacetic Acid
8.9 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Dibromochloromethane
8.575 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Monochloroacetic Acid
4.81 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Chromium
3.26 µg/L 3.3%
of the EPA limit 100 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Bromoform
2.44 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Monobromoacetic Acid
2.255 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Dibromoacetic Acid
1.96 µg/L
No EPA limit set
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Combined Radium (-226 And -228)
0.9000 pCi/L 18%
of the EPA limit 5 pCi/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2012
1/1 SYR4
Antimony, Total
0.4000 µg/L 6.7%
of the EPA limit 6 µg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2019
1/1 SYR4
Lead
0.0028 mg/L 19%
of the EPA limit 0.0150 mg/L
Main supplier: ONTARIO TOWN BENEFIT AREA #1 · 10,136 people · 2023
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 Ontario

SupplierPopulation served
ONTARIO TOWN BENEFIT AREA #1 10,136

Frequently asked questions about Ontario tap water

Is Ontario tap water safe to drink?

EPA testing detected 19 contaminants in the water serving Ontario. 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 Ontario?

1 public water supplier report drinking-water monitoring for Ontario, New York to the EPA. Each is listed above with its population served.

What contaminants are in Ontario's water?

The contaminants EPA monitoring detected in Ontario include Fluoride, Nitrate, Nitrate-Nitrite, TTHM, Chloroform. 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.