Is Londonderry, NH Tap Water Safe to Drink?
Graded F — but Copper and PFOA were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
39/100
waterverge.com Londonderry, NH — Water Quality Report
Londonderry's drinking water received a grade of F (39 out of 100), indicating failing water quality. The city's 19 water systems serve approximately 9,297 residents using purchased surface water.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound, with levels exceeding EPA maximum contaminant levels in the water supply.
The system has 605 violations on record, including 134 health-based violations. 109 remain unresolved.
What to know about Londonderry's water
Londonderry ranks #99 out of 119 cities in New Hampshire for water quality, placing it among the lowest-rated 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.
Of particular concern: PFAS "forever chemical" levels exceed the 2024 EPA maximum contaminant levels. These synthetic compounds don't break down naturally and require specialized filtration such as reverse osmosis or granular activated carbon.
The system has seen 8 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Londonderry, NH water safe to drink?
Londonderry's drinking water has significant quality concerns based on EPA testing data. With a grade of F (39/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 19 water systems serve approximately 9,297 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Londonderry
A timeline of significant water quality events, violations, and data updates.
PFAS levels exceed EPA maximum contaminant levels. Reverse osmosis or activated carbon filtration recommended.
Latest EPA compliance and testing data incorporated into Londonderry's water quality assessment. Grade: F (39/100).
Contaminants: Lead and Copper Rule.
1 health-based. Contaminants: Groundwater Rule.
1 health-based. Contaminants: Combined Radium (-226 and -228).
Federal disaster declaration (FEMA DR-3360). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Londonderry's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
PFAS "forever chemicals" exceed EPA maximum contaminant levels. Reverse osmosis or granular activated carbon filtration strongly recommended.
Violation history
Londonderry's water system has 605 total violations on record, including 134 health-based violations. 109 remain unresolved. 8 violations were issued in the last 5 years.
Flood & environmental risk
Hillsborough County has experienced 9 federally declared disasters since 1973. 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 Souhegan River, Nashua River, Merrimack River, Beaver Brook.
Where does Londonderry's water come from?
Londonderry's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 19 water systems serving approximately 9,297 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Souhegan River (river), Nashua River (river), Merrimack River (river), Beaver Brook (river).
What Londonderry residents can do
Recommended: Reverse osmosis system. This addresses the specific contaminants found in Londonderry'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.
Londonderry'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 ↓Forever chemicals overview
National PFAS report →Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Londonderry
Industrial polluters nearby
Reported releases to surface water by facilities near Londonderry, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
BROX INDUSTRIES INC HUDSON, NH03051 | — | — | 5.4 mi |
PARKER HANNIFIN CORP CHOMERICS DIV HUDSON, NH03051 | — | — | 9.1 mi |
MORGAN ADVANCED CERAMICS INC HUDSON, NH03051 | — | — | 5.1 mi |
HOLOGIC INC LONDONDERRY, NH03053 | — | — | 6.4 mi |
ALCUMET INC LONDONDERRY, NH03053 | — | — | 5.4 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Londonderry
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- TINKHAM GARAGE0.8 mi
- AUBURN ROAD LANDFILL5.3 mi
- NEW HAMPSHIRE PLATING CO6.4 mi
- MOHAWK TANNERY8.8 mi
Source: EPA Superfund National Priorities List
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
Hillsborough County has experienced 9 federally declared disasters since 1973. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Londonderry'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. | 0.0 | 15 | ppb | Inorganic | Safe |
| 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. | 3.77 | 1.3 | mg/L | Inorganic | Over Limit |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | ND | HI | µg/L | PFAS | Not Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | ND | HI | µg/L | PFAS | Not Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | ND | HI | µg/L | PFAS | Not Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | ND | HI | µg/L | PFAS | Not Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | 0.006 | 0.004 | µg/L | PFAS | Over MCL |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | ND | HI | µg/L | PFAS | Not Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Londonderry compares by contaminant
Explore where Londonderry ranks among all New Hampshire cities for specific contaminants.
Water source & infrastructure
Where Londonderry's water comes from
Londonderry'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 private ownership and serves approximately 9,297 people through 19 water systems.
Water bodies near Londonderry
Londonderry is located near 4 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Londonderry
| System Name | PWSID | Population | Source |
|---|---|---|---|
| LONDONDERRY | NH1391010 | 5,380 | SWP |
| BROOK PARK ESTS | NH1392060 | 875 | SWP |
| CENTURY VILLAGE CONDOS | NH1392180 | 875 | GW |
| AVERY ESTATES | NH1392250 | 380 | SWP |
| MINISTERIAL/PARRISH HILLS | NH1392310 | 298 | GW |
| OAKRIDGE CONDOS | NH1392010 | 250 | GW |
| SPRINGWOOD HILLS | NH1392260 | 225 | SWP |
| HARVEST VILLAGE | NH1392290 | 175 | GW |
| OLDE COUNTRY VILLAGE | NH1392030 | 130 | GW |
| PONDEROSA MHP | NH1393060 | 110 | GW |
| HANAFIN FARM | NH1392330 | 105 | GW |
| PINEHAVEN WATER TRUST | NH1392040 | 88 | GW |
| ROLLING MEADOWS CONDOS I | NH1392200 | 88 | GW |
| WAGON WHEEL | NH1393050 | 88 | GW |
| BOUMIL GROVE CONDOS | NH1392050 | 72 | GW |
| ROLLING MEADOWS CONDOS III | NH1392220 | 50 | GW |
| ROLLING MEADOWS CONDOS IV | NH1392230 | 42 | GW |
| SOUTHVIEW CONDOS | NH1392300 | 38 | GW |
| BITIM APARTMENTS | NH1392320 | 28 | GW |
How Londonderry compares
Full New Hampshire rankings →Londonderry's score of 39/100 is below the average of 69/100 among major New Hampshire cities. 10 of 10 nearby cities score higher.
Nearby cities
View New Hampshire rankings →About Londonderry, NH
Wikipedia →Nashua is a city in southern New Hampshire, United States. As of the 2020 census, it had a population of 91,322, the second-largest in northern New England after nearby Manchester. It is one of two county seats of New Hampshire's most populous county, Hillsborough; the other being Manchester.
Learn more about your water
Guides and resources related to Londonderry's water quality findings.
Explore water quality across Rockingham
Frequently asked questions
Is Londonderry, NH tap water safe to drink?
Londonderry's water quality earned a grade of F (39/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #99 out of 119 cities tested in New Hampshire.
What contaminants are in Londonderry's water?
Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 605 violations are on record.
How is Londonderry'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 Londonderry?
PFAS compounds exceed EPA limits — a reverse osmosis or activated carbon filter is recommended.
Where does Londonderry's water come from?
Londonderry's water is sourced from Purchased surface water. The city has 19 water systems serving approximately 9,297 residents.
What health violations has Londonderry's water system had?
Londonderry has 134 health-based violations on record. The most recent violation was recorded in October 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 109 violations remain unresolved.
How does Londonderry's water compare to other cities?
Londonderry ranks #99 out of 119 cities in New Hampshire (better than 17% of state cities) and #15285 out of 15744 cities nationally (3th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.