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Tap water quality report

Londonderry

EPA monitoring tested this supplier for 44 contaminants and detected 13. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

44
contaminants tested
13
detected
6,255
people served
0
health-based violations
Water source
SWP
Ownership
Private
Counties served
Rockingham

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.

0
health-based violations
8
violations on file
0
still open
ViolationTypeStatusPeriod
MR Monitoring Resolved 2013-10-01 → 2014-01-01
MR Monitoring Resolved 2013-10-01 → 2014-01-01
MR Monitoring Resolved 2013-10-01 → 2014-01-01
MR Monitoring Resolved 2013-10-01 → 2014-01-01
MR Monitoring Resolved 2013-10-01 → 2014-01-01
MR Monitoring Resolved 2013-10-01 → 2014-01-01
MR Monitoring Resolved 2013-10-01 → 2014-01-01
MR Monitoring Resolved 2013-10-01 → 2014-01-01

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
PFOA 0.0064 µg/L 3/4 2024

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Bromodichloromethane
5.3 µg/L
No EPA limit set
51/51 SYR4 2014–2019
Chloroform
20 µg/L
No EPA limit set
51/51 SYR4 2014–2019
TTHM
26 µg/L 33%
of the EPA limit 80 µg/L
51/51 SYR4 2014–2019
Dibromochloromethane
1 µg/L
No EPA limit set
44/51 SYR4 2014–2019
Dichloroacetic Acid
11 µg/L
No EPA limit set
44/51 SYR4 2014–2019
Total Haloacetic Acids (HAA5)
20 µg/L 33%
of the EPA limit 60 µg/L
44/51 SYR4 2014–2019
Copper
156 µg/L 12%
of the EPA limit 1300 µg/L
21/21 SYR4 2015–2018
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
14/14 LCR 2024
Lead
2.2 µg/L 15%
of the EPA limit 15 µg/L
3/21 SYR4 2015–2018
Monochloroacetic Acid
15 µg/L
No EPA limit set
3/51 SYR4 2014–2019
Trichloroacetic Acid
8 µg/L
No EPA limit set
2/51 SYR4 2014–2019
Dibromoacetic Acid
1.4 µg/L
No EPA limit set
1/51 SYR4 2014–2019
31 contaminants tested, none detected
11Cl-PF3OUdS4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaBromoformHfpo-DaMonobromoacetic AcidNetfosaaNfdhaNmefosaaPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOSPfpeaPfpesPftaPftrdaPfunaLithium

Utility contact

Contact
LESLIE MORGAN

Frequently asked questions about Londonderry

Is Londonderry tap water safe to drink?

EPA monitoring detected 13 contaminants in Londonderry'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 Londonderry's water?

EPA monitoring detected Bromodichloromethane, Chloroform, TTHM, Dibromochloromethane, Dichloroacetic Acid, and others. The full list with the level and data source for each is above.

How many people does Londonderry serve?

Londonderry reports serving 6,255 people in New Hampshire, per its EPA record.

Has Londonderry had any water quality violations?

The EPA has 8 violations on file for Londonderry, of which 0 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.