01The verdict: is Northumberland water safe?
Northumberland's drinking water has significant quality concerns based on EPA testing data. With a grade of C+ (69.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 2,715 residents using groundwater (wells).
Lead is over its legal limit
Measured at 168.0 ppb against the EPA Action Level of 15 ppb. The ledger below shows how far over — and which filter removes it.
See the measurement ↓Top half in New Hampshire
Northumberland ranks #45 of 98 graded New Hampshire cities.
See the comparison ↓Check back after the next refresh
EPA data updates on a rolling basis; we fold in new samples and violations every month.
Get alerts ↓Northumberland's drinking water received a grade of C+ (69.3 out of 100), indicating fair water quality. The city's 2 water systems serve approximately 2,715 residents using groundwater.
Lead levels were measured at 168.0 ppb (90th percentile), which exceeds the EPA action level of 15 ppb. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 43 violations on record, including 4 health-based violations. 9 remain unresolved.
Northumberland ranks #45 out of 98 cities in New Hampshire for water quality, placing it mid-range in the state. Northumberland relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. Lead levels exceed the EPA action level of 15 ppb, which typically indicates aging lead service lines or lead solder in the distribution system. An NSF 53-certified filter is strongly recommended for drinking and cooking water. As a small community water system, Northumberland may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Northumberland's water
Every contaminant flagged in Northumberland, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Over Limit — EPA Action Level: 15 ppb
Exceeds the EPA action level. Lead enters at the service line, not the treatment plant — your address matters more than the city average. Lead service line replacement and an NSF 53-certified point-of-use filter are recommended.Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 168.0 | 15 | ppb | Inorganic | Over Limit |
Cities ranked by 90th-percentile lead PF PFAS in New Hampshire
Cities ranked by compounds detected Cu Copper in New Hampshire
Cities ranked by 90th-percentile copper
03Northumberland's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 43 violations on record, including 4 health-based violations. 9 remain unresolved.
9 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▲ Up 141 ppb since 1993. The latest reading (168 ppb, 2004) is over the action level. Sampled at higher-risk homes (90th percentile).
04Where Northumberland's water comes from
Northumberland's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
2 systems
2 water systems, operated under local government ownership.
2,715 people
Residents served across Northumberland's service area.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by local government ownership and serves approximately 2,715 people through 2 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| GROVETON WATER SYS | NH1781010 | 2,650 | Groundwater |
| LOST NATION WATER | NH1781030 | 65 | Groundwater |
Water bodies near Northumberland
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05How Northumberland compares
Scores for nearby New Hampshire cities on one line, with the average marked.
dashed line = New Hampshire average (66/100)
Northumberland scores 69.3/100 — on par with the New Hampshire average of 66/100. It outscores 5 of 10 nearby cities. Full New Hampshire rankings →
50.9 / 100ANashua, NH
88.7 / 100DConcord, NH
51.3 / 100BPortsmouth, NH
80.7 / 100AKeene, NH
89.2 / 100BDover, NH
84 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
06What to do at home
Steps matched to what testing actually found in Northumberland's water — not generic advice.
Filter drinking & cooking water
NSF 53-certified pitcher or under-sink filter. Lead level (168.0 ppb) exceeds the EPA action level of 15 ppb
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Northumberland alerts
We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.
All water alerts →Frequently asked questions
Is Northumberland, NH tap water safe to drink?
Northumberland's water quality earned a grade of C+ (69.3/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #45 out of 98 cities tested in New Hampshire.
What contaminants are in Northumberland's water?
Lead was measured at 168.0 ppb (90th percentile). 43 violations are on record.
How is Northumberland's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Northumberland?
Yes — lead levels exceed the EPA action level of 15 ppb. We recommend an NSF 53-certified filter or reverse osmosis system. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Northumberland's water come from?
Northumberland's water is sourced from Groundwater. The city has 2 water systems serving approximately 2,715 residents.
What health violations has Northumberland's water system had?
Northumberland has 4 health-based violations on record. The most recent violation was recorded in September 2020. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 9 violations remain unresolved.
Is Northumberland's groundwater at risk of contamination?
Northumberland uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 43 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Northumberland's water compare to other cities?
Northumberland ranks #45 out of 98 cities in New Hampshire (better than 54% of state cities) and #10784 out of 15382 cities nationally (30th percentile). The grade of C+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.