01The verdict: is New Castle water safe?
New Castle's drinking water has significant quality concerns based on EPA testing data. With a grade of C+ (66.7/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 910 residents using surface water (rivers, lakes, or reservoirs).
Lead is over its legal limit
Measured at 17.0 ppb against the EPA Action Level of 15 ppb. The ledger below shows how far over — and which filter removes it.
See the measurement ↓910 people, 1 system
All figures on this page come from federal EPA compliance and testing data for the systems serving this city.
See the systems ↓1 violation in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓New Castle's drinking water received a grade of C+ (66.7 out of 100), indicating fair water quality. The city's 1 water system serves approximately 910 residents using purchased surface water.
Lead levels were measured at 17.0 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 29 violations on record, including 20 health-based violations. 3 remain unresolved.
New Castle ranks #50 out of 98 cities in New Hampshire for water quality, placing it below average in the state. The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection. 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, New Castle may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in New Castle's water
Every contaminant flagged in New Castle, 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. | 17.0 | 15 | ppb | Inorganic | Over Limit |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.45 | 1.3 | mg/L | 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
03New Castle'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 29 violations on record, including 20 health-based violations. 3 remain unresolved.
7 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.
▼ Down 34 ppb since 1993. The latest reading (17 ppb, 2007) is over the action level. Sampled at higher-risk homes (90th percentile).
1.4mg/L(1993)
One sampling round on record — 112% of the 1.3mg/L EPA action level. Sampled at higher-risk homes (90th percentile).
04Where New Castle's water comes from
New Castle's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Purchased Surface Water
Rivers, lakes, or reservoirs — more exposed to runoff, agriculture, and seasonal swings than groundwater.
Wholesale supplier
Multi-barrier treatment: coagulation, sedimentation, filtration, and disinfection to meet EPA standards.
1 system
1 water system, operated under local government ownership.
910 people
Residents served across New Castle's service area.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards. These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge. The system is operated by local government ownership and serves approximately 910 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| NEW CASTLE WATER WORKS | NH1661010 | 910 | Purchased Surface Water |
Water bodies near New Castle
As a surface-water system, these water bodies may directly influence New Castle's drinking water supply.
05Pressure on New Castle's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Flood & storm history
10 federal disaster declarations on record for Rockingham County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Rockingham County is in D2 (severe drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How New Castle compares
Scores for nearby New Hampshire cities on one line, with the average marked.
dashed line = New Hampshire average (66/100)
New Castle scores 66.7/100 — 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.→
07What to do at home
Steps matched to what testing actually found in New Castle's water — not generic advice.
Filter drinking & cooking water
NSF 53-certified pitcher or under-sink filter. Lead level (17.0 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 New Castle alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is New Castle, NH tap water safe to drink?
New Castle's water quality earned a grade of C+ (66.7/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #50 out of 98 cities tested in New Hampshire.
What contaminants are in New Castle's water?
Lead was measured at 17.0 ppb (90th percentile). 29 violations are on record.
How is New Castle'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 New Castle?
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 New Castle's water come from?
New Castle's water is sourced from Purchased surface water. The city has 1 water system serving approximately 910 residents.
What health violations has New Castle's water system had?
New Castle has 20 health-based violations on record. The most recent violation was recorded in October 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
How does New Castle's water compare to other cities?
New Castle ranks #50 out of 98 cities in New Hampshire (better than 49% of state cities) and #11175 out of 15382 cities nationally (27th percentile). The grade of C+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does New Castle's small water system affect quality?
New Castle's system serves approximately 910 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 29 violations on record.