Drinking water quality, NH
New Hampshire contaminants ranked by SDWA exceedance
Which regulated contaminants exceed their maximum contaminant level (MCL) most often across New Hampshire's community water systems, per EPA's Six-Year Review sample-level dataset (2012-2019). Source data is public; every value is citable.
Sample data. SYR4 ingest is in flight on prod; this page renders deterministic placeholder data until the V1 importer lands the NH cohort.
Top 5 contaminants by exceedance count
| Contaminant | Category | Samples | Above MCL | Munis affected |
|---|---|---|---|---|
| total trihalomethanes | disinfection byproduct | 1,240 | 89 | 37 |
| haloacetic acids (HAA5) | disinfection byproduct | 980 | 61 | 20 |
| lead | lead copper | 2,100 | 34 | 12 |
| arsenic | inorganic | 720 | 12 | 12 |
| nitrate (as nitrogen) | inorganic | 1,850 | 8 | 8 |
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.