Is New Castle, NH Tap Water Safe to Drink?
Graded C+ — but Lead and Copper were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
66.7/100
waterverge.com New Castle, NH — Water Quality Report
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.
What to know about New Castle's water
New Castle ranks #56 out of 119 cities in New Hampshire for water quality, placing it mid-range 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.
Water quality score
See methodology →Is New Castle, NH water safe to drink?
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).
Recent water quality updates for New Castle
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into New Castle's water quality assessment. Grade: C+ (66.7/100).
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-4740). Flood event — may have impacted local water infrastructure.
1 health-based. Contaminants: TTHM.
Federal disaster declaration (FEMA DR-4370). Coastal Storm event — may have impacted local water infrastructure.
1 health-based. Contaminants: TTHM.
Key contaminant findings
Based on the most recent EPA sampling data for New Castle's water supply.
Exceeds EPA action level. Lead service line replacement and point-of-use filtration recommended.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
New Castle's water system has 29 total violations on record, including 20 health-based violations. 3 remain unresolved. 1 violation was issued in the last 5 years.
Flood & environmental risk
Rockingham County has experienced 10 federally declared disasters since 1987. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Winnicut River.
Where does New Castle's water come from?
New Castle's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 910 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Winnicut River (river).
What New Castle residents can do
Recommended: NSF 53-certified pitcher or under-sink filter. This addresses the specific contaminants found in New Castle's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
New Castle's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Drought conditions
D2 — severe droughtRockingham County is currently in D2 (severe drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Rockingham County has experienced 10 federally declared disasters since 1987. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in New Castle's water supply, we recommend the following filter types.
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 |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.450 mg/L (1993)
EPA action level: 1.3 mg/L
See how New Castle compares by contaminant
Explore where New Castle ranks among all New Hampshire cities for specific contaminants.
Water source & infrastructure
Where New Castle's water comes from
New Castle's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
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.
Water bodies near New Castle
New Castle is located near 1 notable water body. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving New Castle
| System Name | PWSID | Population | Source |
|---|---|---|---|
| NEW CASTLE WATER WORKS | NH1661010 | 910 | SWP |
How New Castle compares
Full New Hampshire rankings →New Castle's score of 66.7/100 is on par with the average of 69/100 among major New Hampshire cities. It outscores 4 of 10 nearby cities. 6 of 10 nearby cities score higher.
Nearby cities
View New Hampshire rankings →About New Castle, NH
Wikipedia →Portsmouth is a city in Rockingham County, New Hampshire, United States. It had a population of 21,956 at the 2020 census. A historic seaport and popular summer tourist destination on the Piscataqua River bordering the state of Maine, Portsmouth was formerly the home of the Pease Air Force Base, since converted to Portsmouth International Airport at Pease.
Learn more about your water
Guides and resources related to New Castle's water quality findings.
Explore water quality across Rockingham
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 #56 out of 119 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 #56 out of 119 cities in New Hampshire (better than 53% of state cities) and #11345 out of 15744 cities nationally (28th 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.