Compliance record
Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.
| Violation | Type | Status | Period |
|---|---|---|---|
| MCL | Health-based | Resolved | 2004-08-01 → 2004-08-31 |
| MCL | Health-based | Resolved | 2004-08-01 → 2004-08-31 |
| MCL | Health-based | Resolved | 2004-08-01 → 2004-08-31 |
| MCL | Health-based | Resolved | 2004-08-01 → 2004-08-31 |
| MCL | Health-based | Resolved | 1998-09-01 → 1998-09-30 |
| MCL | Health-based | Resolved | 1998-09-01 → 1998-09-30 |
| MCL | Health-based | Resolved | 1998-09-01 → 1998-09-30 |
| MCL | Health-based | Resolved | 1998-09-01 → 1998-09-30 |
| MCL | Health-based | Resolved | 1998-06-01 → 1998-06-30 |
| MCL | Health-based | Resolved | 1998-06-01 → 1998-06-30 |
PFAS detected
| Contaminant | Max | Detection rate | Period |
|---|---|---|---|
| PFOA | 0.0046 µg/L | 3/4 | 2024 |
Other contaminants detected
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Bromodichloromethane | 2.16 µg/L No EPA limit set
worst single sample: 5.6 µg/L | 80/80 | SYR4 | 2014–2019 |
| Chloroform | 4.845 µg/L No EPA limit set
worst single sample: 20 µg/L | 80/80 | SYR4 | 2014–2019 |
| TTHM | 7.52 µg/L 9.4% of the EPA limit 80 µg/L
worst single sample: 26 µg/L | 80/80 | SYR4 | 2014–2019 |
| Total Haloacetic Acids (HAA5) | 16.3 µg/L 27% of the EPA limit 60 µg/L
worst single sample: 29.5 µg/L | 71/80 | SYR4 | 2014–2019 |
| Dichloroacetic Acid | 7.48 µg/L No EPA limit set
worst single sample: 11 µg/L | 69/80 | SYR4 | 2014–2019 |
| Dibromochloromethane | 0.9000 µg/L No EPA limit set
worst single sample: 1 µg/L | 68/80 | SYR4 | 2014–2019 |
| Copper | 122.807 µg/L 9.4% of the EPA limit 1300 µg/L
worst single sample: 313.795 µg/L | 31/31 | SYR4 | 2014–2017 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 14/14 | LCR | 2023 |
| Monochloroacetic Acid | 23 µg/L No EPA limit set
worst single sample: 27 µg/L | 6/80 | SYR4 | 2014–2019 |
| Lead | 24.7968 µg/L 165% of the EPA limit, at the 95th percentile of samples — 15 µg/L
worst single sample: 26.8364 µg/L | 4/31 | SYR4 | 2014–2017 |
| Trichloroacetic Acid | 8.57 µg/L No EPA limit set
worst single sample: 8.6 µg/L | 4/80 | SYR4 | 2014–2019 |
32 contaminants tested, none detected
Utility contact
Frequently asked questions about Derry Water Dept
Is Derry Water Dept tap water safe to drink?
EPA monitoring detected 12 contaminants in Derry Water Dept's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.
What contaminants were detected in Derry Water Dept's water?
EPA monitoring detected Bromodichloromethane, Chloroform, TTHM, Total Haloacetic Acids (HAA5), Dichloroacetic Acid, and others. The full list with the level and data source for each is above.
How many people does Derry Water Dept serve?
Derry Water Dept reports serving 17,370 people in New Hampshire, per its EPA record.
Has Derry Water Dept had any water quality violations?
The EPA has 12 violations on file for Derry Water Dept, of which 12 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.