What was found in ZIP 63109
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 |
|---|---|---|---|
| Nitrate-Nitrite | 4092 µg/L 41% of the EPA limit 10000 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 6779 µg/L — CLARK COUNTY CONS PWSD 1 · 7,140 people · 2019 | 2/3 | SYR4 |
| Nitrate | 4067.5 µg/L 41% of the EPA limit 10000 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Copper | 43.6479 µg/L 3.4% of the EPA limit 1300 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 863.25 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2018 | 3/3 | SYR4 |
| Fluoride | 650 µg/L 16% of the EPA limit 4000 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 2/3 | SYR4 |
| TTHM | 25.575 µg/L 32% of the EPA limit 80 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 70.265 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2019 | 3/3 | SYR4 |
| Chloroform | 20.44 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 59.3 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 33.7 µg/L 56% of the EPA limit 60 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 54.9 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2019 | 2/3 | SYR4 |
| Barium | 25.3265 µg/L 1.3% of the EPA limit 2000 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 54.07 µg/L — CLARK COUNTY CONS PWSD 1 · 7,140 people · 2017 | 2/3 | SYR4 |
| Lithium | 45.3 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2024 | 1/3 | UCMR-5 |
| Nitrite | 37.55 µg/L 3.8% of the EPA limit 1000 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Dichloroacetic Acid | 28.65 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 33.435 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2019 | 3/3 | SYR4 |
| Trichloroacetic Acid | 3.636 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 19.76 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2019 | 3/3 | SYR4 |
| Lead | 6.0613 µg/L 40% of the EPA limit 15 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 15.66 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2018 | 3/3 | SYR4 |
| Bromodichloromethane | 4.996 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 12.865 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2019 | 3/3 | SYR4 |
| Monobromoacetic Acid | 4.9795 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 8.661 µg/L — THOMAS HILL PWSD 1 · 11,250 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 6.6834 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Dibromochloromethane | 1.5565 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 3.266 µg/L — CLARK COUNTY CONS PWSD 1 · 7,140 people · 2019 | 3/3 | SYR4 |
| Chromium | 1.735 µg/L 1.7% of the EPA limit 100 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019
Highest in the ZIP: 3.0075 µg/L — CLARK COUNTY CONS PWSD 1 · 7,140 people · 2017 | 2/3 | SYR4 |
| Dibromoacetic Acid | 2.8958 µg/L No EPA limit set Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 3/3 | SYR4 |
| Selenium | 2.4296 µg/L 4.9% of the EPA limit 50 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Atrazine | 1.315 µg/L 44% of the EPA limit 3 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Simazine | 1.0555 µg/L 26% of the EPA limit 4 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Arsenic | 1.05 µg/L 11% of the EPA limit 10 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Bromoform | 0.7725 µg/L No EPA limit set Highest in the ZIP: CLARK COUNTY CONS PWSD 1 · 7,140 people · 2019 | 1/3 | SYR4 |
| Antimony, Total | 0.3840 µg/L 6.4% of the EPA limit 6 µg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2019 | 1/3 | SYR4 |
| Pfba | 0.0093 µg/L No EPA limit set Highest in the ZIP: THOMAS HILL PWSD 1 · 11,250 people · 2025 | 1/3 | UCMR-5 |
| Lead | 0.0018 mg/L 12% of the EPA limit 0.0150 mg/L Main supplier: ST LOUIS CITY PWS · 304,709 people · 2025
Highest in the ZIP: 0.0031 mg/L — THOMAS HILL PWSD 1 · 11,250 people · 2024 | 3/3 | 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 63109
| Supplier | State | Population served |
|---|---|---|
| ST LOUIS CITY PWS | MO | 304,709 |
| THOMAS HILL PWSD 1 | MO | 11,250 |
| CLARK COUNTY CONS PWSD 1 | MO | 7,140 |
Frequently asked questions about ZIP 63109 tap water
Is the tap water in ZIP 63109 safe to drink?
EPA testing detected 27 contaminants across the water suppliers serving ZIP 63109. 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 63109?
3 public water suppliers report EPA drinking-water monitoring for ZIP 63109. Each is listed above with its population served.
What contaminants are in ZIP 63109's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Copper, Fluoride, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.