Is Derry, 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.

14 public water systems serve parts of Derry. The largest, Derry Water Dept, serves 17,528 people. 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.

Derry homes and lead pipes

40%

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

10%

built before 1950 (New Hampshire 22%)

30%

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 Derry town (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Derry

Drew Woods Water System
1,413 people · Purchased surface water · New Hampshire · lists this city
Not in EPA's PFAS sample
Maple Hill Acres Water System
500 people · Purchased surface water · New Hampshire · lists this city
Not in EPA's PFAS sample
Oakwood Terrace Water System
310 people · Purchased surface water · New Hampshire · lists this city
Not in EPA's PFAS sample
Glen Ridge Dev Water System
263 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Maple Haven Water System
258 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Hi and Lo Estates Water System
150 people · Purchased surface water · New Hampshire · lists this city
Not in EPA's PFAS sample

7 more systems

Centennial Estates Water System
140 people · Groundwater · New Hampshire · lists this city
Nitrate violation
Annie Oakley MHP
127 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Farmstead Acres Water System
93 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Autumn Woods Water System
73 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Willow Bend Water System
55 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample
Old Coach Village Water System
50 people · Groundwater · New Hampshire · lists this city
Arsenic violations
Running Brook Water System
47 people · Groundwater · New Hampshire · lists this city
Not in EPA's PFAS sample

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
Londonderry 6 mi Derry Water Dept	Derry Water Dept	None above limits	0 ppb
Salem 8 mi Salem Water Dept	Salem Water Dept	Above limit	2 ppb
Manchester 11 mi Manchester Water Works	Manchester Water Works	Above limit	0 ppb
Hudson 11 mi Hudson Water Dept	Hudson Water Dept	Above limit	0 ppb
Merrimack 12 mi Merrimack Village District	Merrimack Village District	None above limits	0 ppb
Nashua 14 mi Pennichuck Water Works	Pennichuck Water Works	None above limits	0 ppb

Derry ZIP codes (1)

03038

Questions

Is Derry 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 Derry, NH?

14 public water systems serve parts of Derry. 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 Derry 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 Derry homes have lead pipes?

Census estimates put 40% of Derry 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.