Drinking water quality, IA
Iowa contaminants ranked by SDWA exceedance
Which regulated contaminants exceed their maximum contaminant level (MCL) most often across Iowa'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 | - | 1,811 | 0 | 498 |
| 1,1-dichloroethylene | - | 1,815 | 0 | 498 |
| 1,2,4-trichlorobenzene | - | 1,834 | 0 | 498 |
| 1,2-dibromo-3-chloropropane | - | 10 | 0 | 2 |
| 1,2-dichloroethane | - | 1,834 | 0 | 498 |
| 1,2-dichloropropane | - | 1,811 | 0 | 498 |
| 2,4,5-tp | - | 1,084 | 0 | 486 |
| 2,4-d | - | 1,812 | 0 | 498 |
| alachlor | - | 1,923 | 0 | 498 |
| antimony, total | inorganic | 1,019 | 0 | 477 |
| arsenic | inorganic | 1,618 | 0 | 482 |
| asbestos | - | 89 | 0 | 81 |
| atrazine | - | 2,085 | 0 | 498 |
| barium | inorganic | 1,023 | 0 | 478 |
| 1,1,1-trichloroethane | - | 1,820 | 0 | 498 |
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.