Drinking water quality, MO
Missouri contaminants ranked by SDWA exceedance
Which regulated contaminants exceed their maximum contaminant level (MCL) most often across Missouri's community water systems, per EPA's Six-Year Review sample-level dataset (2012-2019). Source data is public; every value is citable.
Top 15 contaminants by exceedance count
| Contaminant | Category | Samples | Above MCL | Munis affected |
|---|---|---|---|---|
| 1,1,2-trichloroethane | - | 4,787 | 0 | 552 |
| 1,1-dichloroethylene | - | 4,787 | 0 | 552 |
| 1,2,4-trichlorobenzene | - | 4,787 | 0 | 552 |
| 1,2-dibromo-3-chloropropane | - | 4,788 | 0 | 552 |
| 1,2-dichloroethane | - | 4,785 | 0 | 552 |
| 1,2-dichloropropane | - | 4,786 | 0 | 552 |
| 2,3,7,8-tcdd | - | 3 | 0 | 1 |
| 2,4,5-tp | - | 2,334 | 0 | 548 |
| 2,4-d | - | 2,335 | 0 | 548 |
| alachlor | - | 3,620 | 0 | 549 |
| antimony, total | inorganic | 4,435 | 0 | 552 |
| arsenic | inorganic | 4,436 | 0 | 552 |
| atrazine | - | 3,687 | 0 | 549 |
| barium | inorganic | 4,440 | 0 | 552 |
| 1,1,1-trichloroethane | - | 4,785 | 0 | 552 |
For citizens
Look up your own water system by name on the muni search, then read the drinking-water quality band on its profile page for per-contaminant readings + MCL ratios.
For chemical suppliers
Contaminants near or above MCL signal treatment-chemical procurement pressure. Lane intelligence pairs this with per-chemical bid timing on the supplier tier.