Drinking water quality, DE
Delaware contaminants ranked by SDWA exceedance
Which regulated contaminants exceed their maximum contaminant level (MCL) most often across Delaware'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 | - | 2,555 | 0 | 61 |
| 1,1-dichloroethylene | - | 2,555 | 0 | 61 |
| 1,2,4-trichlorobenzene | - | 2,609 | 0 | 61 |
| 1,2-dibromo-3-chloropropane | - | 2,958 | 0 | 61 |
| 1,2-dichloroethane | - | 2,555 | 0 | 61 |
| 1,2-dichloropropane | - | 2,556 | 0 | 61 |
| 2,4,5-tp | - | 944 | 0 | 54 |
| 2,4-d | - | 944 | 0 | 54 |
| alachlor | - | 1,032 | 0 | 56 |
| antimony, total | inorganic | 851 | 0 | 56 |
| arsenic | inorganic | 996 | 0 | 56 |
| asbestos | - | 1 | 0 | 1 |
| atrazine | - | 1,032 | 0 | 56 |
| barium | inorganic | 851 | 0 | 56 |
| 1,1,1-trichloroethane | - | 2,556 | 0 | 61 |
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.