What was found in ZIP 46307
The level at this ZIP's main supplier, the highest level anywhere in it, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Fluoride | 837 µg/L 21% of the EPA limit 4000 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2019
Highest in the ZIP: 1200 µg/L — CUII - TWIN LAKES · 8,000 people · 2018 | 3/5 | SYR4 |
| Copper | 375.8 µg/L 29% of the EPA limit 1300 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2018
Highest in the ZIP: 946 µg/L — ST. JOHN MUNICIPAL WATER UTILITY · 25,700 people · 2017 | 5/5 | SYR4 |
| Nitrate | 446 µg/L 4.5% of the EPA limit 10000 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2019 | 2/5 | SYR4 |
| Nitrate-Nitrite | 395.5 µg/L 4% of the EPA limit 10000 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2019 | 2/5 | SYR4 |
| Lithium | 83.8 µg/L No EPA limit set Highest in the ZIP: ST. JOHN MUNICIPAL WATER UTILITY · 25,700 people · 2025 | 2/5 | UCMR-5 |
| Barium | 63.4 µg/L 3.2% of the EPA limit 2000 µg/L Highest in the ZIP: CUII - TWIN LAKES · 8,000 people · 2018 | 2/5 | SYR4 |
| Lead | 12.9 µg/L 86% of the EPA limit 15 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2018
Highest in the ZIP: 50.765 µg/L — CUII - TWIN LAKES · 8,000 people · 2017 | 5/5 | SYR4 |
| TTHM | 33.395 µg/L 42% of the EPA limit 80 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2019
Highest in the ZIP: 49.12 µg/L — CORINTH PWD · 3,927 people · 2019 | 5/5 | SYR4 |
| Chloroform | 41.87 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2019 | 2/5 | SYR4 |
| Total Haloacetic Acids (HAA5) | 20.475 µg/L 34% of the EPA limit 60 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2019
Highest in the ZIP: 24.975 µg/L — CORINTH PWD · 3,927 people · 2019 | 5/5 | SYR4 |
| Dichloroacetic Acid | 20.16 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2019 | 1/5 | SYR4 |
| Chromium | 16.7 µg/L 17% of the EPA limit 100 µg/L Highest in the ZIP: CUII - TWIN LAKES · 8,000 people · 2018 | 1/5 | SYR4 |
| Bromodichloromethane | 10.5 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2019 | 2/5 | SYR4 |
| Cyanide | 6 µg/L 3% of the EPA limit 200 µg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2019 | 1/5 | SYR4 |
| Gross Alpha, Excl. Radon And U | 0.2330 pCi/L 1.6% of the EPA limit 15 pCi/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2015
Highest in the ZIP: 5.37 pCi/L — CUII - TWIN LAKES · 8,000 people · 2015 | 3/5 | SYR4 |
| Trichloroacetic Acid | 4.2 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2019 | 1/5 | SYR4 |
| Dibromochloromethane | 3.785 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2019 | 2/5 | SYR4 |
| Monochloroacetic Acid | 2.94 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2019 | 1/5 | SYR4 |
| Dibromoacetic Acid | 1.58 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2019 | 1/5 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 1.5 µg/L 25% of the EPA limit 6 µg/L Highest in the ZIP: ST. JOHN MUNICIPAL WATER UTILITY · 25,700 people · 2018 | 1/5 | SYR4 |
| Pfba | 0.0056 µg/L No EPA limit set Highest in the ZIP: CORINTH PWD · 3,927 people · 2023 | 1/5 | UCMR-5 |
| Lead | 0.0030 mg/L 20% of the EPA limit 0.0150 mg/L Main supplier: INDIANA AMERICAN WATER - NORTHWEST · 210,510 people · 2024
Highest in the ZIP: 0.0046 mg/L — CORINTH PWD · 3,927 people · 2025 | 5/5 | 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.
Water suppliers serving ZIP 46307
| Supplier | State | Population served |
|---|---|---|
| INDIANA AMERICAN WATER - NORTHWEST | IN | 210,510 |
| CROWN POINT WATER WORKS | IN | 30,000 |
| ST. JOHN MUNICIPAL WATER UTILITY | IN | 25,700 |
| CUII - TWIN LAKES | IN | 8,000 |
| CORINTH PWD | IL | 3,927 |
Frequently asked questions about ZIP 46307 tap water
Is the tap water in ZIP 46307 safe to drink?
EPA testing detected 22 contaminants across the water suppliers serving ZIP 46307. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.
Which water suppliers serve ZIP 46307?
5 public water suppliers report EPA drinking-water monitoring for ZIP 46307. Each is listed above with its population served.
What contaminants are in ZIP 46307's water?
EPA monitoring detected Fluoride, Copper, Nitrate, Nitrate-Nitrite, Lithium, and others across this ZIP's suppliers. The full list with levels and sources is above.