Is Londonderry, NH tap water safe?

Data: U.S. EPA · How we read the data · How we check it

No federal limits exceeded in EPA data for Derry Water Dept. 1 PFAS were detected below the limits.

18 public water systems serve parts of Londonderry. The largest, Derry Water Dept, serves 17,528 people, and one system here had PFAS above a federal limit. Your water bill names your system.

Largest system

Derry Water Dept

17,528 people · Purchased surface water · EPA ID NH0611010

Buys treated water from Manchester Water Works.

PFAS	Highest average	Limit	Status
PFOA One sample above limit	3.2 ppt	4 ppt	One sample above limit
PFOS Not detected	–	4 ppt	Not detected
PFHxS Not detected	–	10 ppt	Not detected
PFNA Not detected	–	10 ppt	Not detected
HFPO-DA (GenX) Not detected	–	10 ppt	Not detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 0 ppb at the 90th percentile (Dec 2023, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Across New Hampshire, 9 of 49 water systems EPA tested had PFAS above a 2024 federal limit, and 25 systems were above the lead action level in results from the last five years. New Hampshire results.

Londonderry homes and lead pipes

38%

of homes built before 1980 (New Hampshire 52%, US 50%)

built before 1950 (New Hampshire 22%)

14%

of households rent (New Hampshire 27%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Londonderry town (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Londonderry

Londonderry Water System
6,255 people · Purchased surface water · New Hampshire · lists this city
PFOA above limit
Brook Park Ests Water System
880 people · Purchased surface water · New Hampshire · lists this city
Not in EPA's PFAS sample
Avery Estates Water System
383 people · Purchased surface water · New Hampshire · lists this city
Not in EPA's PFAS sample
Ministerial/Parrish Hills Water System
305 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Oakridge Condos Water System
250 people · Groundwater · New Hampshire · lists this city
Radium (combined 226/228) violations
Springwood Hills Water System
228 people · Purchased surface water · New Hampshire · lists this city
Not in EPA's PFAS sample

11 more systems

Harvest Village Water System
185 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Olde Country Village Water System
130 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Ponderosa MHP
110 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Hanafin Farm Water System
105 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Pinehaven Water Trust
95 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Rolling Meadows Condos I Water System
88 people · Groundwater · New Hampshire · lists this city
Nitrate violation
Boumil Grove Condos Water System
72 people · Groundwater · New Hampshire · lists this city
Gross alpha violationsAlso: Radium (combined 226/228) violations · Coliform bacteria violation
Rolling Meadows Condos III
50 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Rolling Meadows Condos IV Water System
42 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Southview Condos Water System
38 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Bitim Apartments Water System
28 people · Groundwater · New Hampshire · lists this city
Arsenic violations

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
Derry 6 mi Derry Water Dept	Derry Water Dept	None above limits	0 ppb
Merrimack 7 mi Merrimack Village District	Merrimack Village District	None above limits	0 ppb
Manchester 8 mi Manchester Water Works	Manchester Water Works	Above limit	0 ppb
Hudson 8 mi Hudson Water Dept	Hudson Water Dept	Above limit	0 ppb
Nashua 10 mi Pennichuck Water Works	Pennichuck Water Works	None above limits	0 ppb
Salem 11 mi Salem Water Dept	Salem Water Dept	Above limit	2 ppb

Londonderry ZIP codes (1)

03053

Questions

Is Londonderry tap water safe to drink?

Derry Water Dept has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Londonderry, NH?

18 public water systems serve parts of Londonderry. The largest is Derry Water Dept (17,528 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Londonderry tap water have PFAS?

Derry Water Dept had 1 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.

Do Londonderry homes have lead pipes?

Census estimates put 38% of Londonderry homes as built before 1980 (New Hampshire: 52%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Derry Water Dept's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.