Tap WaterIndex

← Indiana

Tap water quality report

St. John, IN

EPA monitoring detected 10 contaminants across the 1 water supplier serving St. John. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

1
water supplier
25,700
people served
10
contaminants found
Indiana rankings Lead in Indiana PFAS in Indiana

What was found in St. John's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Copper
1000 µg/L 77%
of the EPA limit 1300 µg/L
 1/1 SYR4
Fluoride
800 µg/L 20%
of the EPA limit 4000 µg/L
 1/1 SYR4
Lithium
83.8 µg/L
No EPA limit set
 1/1 UCMR-5
Barium
24 µg/L 1.2%
of the EPA limit 2000 µg/L
 1/1 SYR4
TTHM
22.3 µg/L 28%
of the EPA limit 80 µg/L
 1/1 SYR4
Lead
17 µg/L 113%
of the EPA limit, in the worst sample — 15 µg/L
 1/1 SYR4
Total Haloacetic Acids (HAA5)
16.2 µg/L 27%
of the EPA limit 60 µg/L
 1/1 SYR4
Gross Alpha, Excl. Radon And U
1.94 pCi/L 13%
of the EPA limit 15 pCi/L
 1/1 SYR4
Di(2-ethylhexyl) Phthalate
1.5 µg/L 25%
of the EPA limit 6 µg/L
 1/1 SYR4
Lead
0.0027 mg/L 18%
of the EPA limit 0.0150 mg/L
 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 single worst sample on record — 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 St. John

SupplierPopulation served
ST. JOHN MUNICIPAL WATER UTILITY 25,700

Frequently asked questions about St. John tap water

Is St. John tap water safe to drink?

EPA testing detected 10 contaminants in the water serving St. John. 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 St. John?

1 public water supplier report drinking-water monitoring for St. John, Indiana to the EPA. Each is listed above with its population served.

What contaminants are in St. John's water?

The contaminants EPA monitoring detected in St. John include Copper, Fluoride, Lithium, Barium, TTHM. The full list, with the highest level found 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.