WaterVerge

Is Nashua, NH Tap Water Safe to Drink?

Graded A-, with 1 unresolved violation on record. See what was cited — and what it means for your tap. What to do next ↓

89K residents served 2 water systems PWSID: NH1621010
Overall Score
88.7 / 100
Violations
1 active
Last Updated
May 2026
Source
Surface water
#11 of 119 in New Hampshire Top 21% nationally
Private
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
A-GRADE
Water Quality Grade
88.7/100
waterverge.com
A- 88.7/100

Nashua, NH — Water Quality Report

Nashua's drinking water received a grade of A- (88.7 out of 100), indicating good water quality. The city's 2 water systems serve approximately 89,148 residents using surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 4 violations on record, including 3 health-based violations. 1 remains unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Nashua's water

Nashua ranks #11 out of 119 cities in New Hampshire for water quality, placing it one of the best 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.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

Hexavalent chromium (chromium-6) was detected at 0.10 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.

Quality Breakdown

Water quality score

See methodology →
88.7 out of 100 Grade A-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
44.1/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
15.6/20
B
1 PFAS compound detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Surface water.
Water Safety

Is Nashua, NH water safe to drink?

Use Caution

Nashua's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (88.7/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 2 water systems serve approximately 89,148 residents using surface water (rivers, lakes, or reservoirs).

1
Active Violations
0.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected
9 events
Disaster History

Recent water quality updates for Nashua

A timeline of significant water quality events, violations, and data updates.

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Nashua's water quality assessment. Grade: A- (88.7/100).

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Arsenic.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Disaster
HURRICANE SANDY

Federal disaster declaration (FEMA DR-3360). Hurricane event — may have impacted local water infrastructure.

Disaster
HURRICANE IRENE

Federal disaster declaration (FEMA DR-3333). Hurricane event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Nashua's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 11.3000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Violation history

Nashua's water system has 4 total violations on record, including 3 health-based violations. 1 remain unresolved.

MCLMRTT
Most recent violations:
Jan 2016 Arsenic Resolved
Sep 2013 Coliform (TCR) Resolved
Oct 2008 Lead and Copper Rule Open
Aug 2002 Surface Water Treatment Rule Resolved

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.

HURRICANE SANDY
Hurricane FEMA DR-3360
HURRICANE IRENE
Hurricane FEMA DR-3333
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3258

Where does Nashua's water come from?

Nashua's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 2 water systems serving approximately 89,148 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 Nashua residents can do

Request your utility's CCR

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.

Monitor alerts during storms

Nashua'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.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
11.3000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
11.8 µg/L
EPA MCL: 60 µg/L · 20% of limit
Within LimitUCMR 4 DataHAA6Br: 6.6 µg/LHAA9: 17.8 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
0.10 µg/L
CA MCL (no federal MCL): 10 µg/L · 1% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
86.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 6% of limit
DetectedUCMR 3 Data
Manganese
Inorganic
Detected
4.6 µg/L
EPA Secondary MCL: 50 µg/L · 9% of limit
DetectedUCMR 4 Data
Chlorate
Disinfection Byproduct
Elevated
190.0 µg/L
EPA Lifetime HA: 210 µg/L · 90% of limit
DetectedUCMR 3 Data
Lithium
Inorganic
Detected
11.3 µg/L
State screening level: 60 µg/L · 19% of limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

4
Total violations
3
Health-based
1
Active / unresolved
Jan 2016
Most recent violation
Compliance Record

Violations & advisories

4 Total
1 Active
3 Health-based
3 Resolved
Violations by category
Arsenic Rule
1
Total Coliform Rule
1
Lead and Copper Rule
1
Surface Water Treatment Rule
1
Oct 2008 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jan 2016 Resolved
Arsenic
Max Contaminant Level
Health-Based Health Resolved Mar 2016
Sep 2013 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Sep 2013
Aug 2002 Resolved
Surface Water Treatment Rule
Treatment Technique
Health-Based Health Resolved Aug 2002
Industrial pollution

Top industrial polluters within 10 miles of Nashua

Industrial polluters nearby

Reported releases to surface water by facilities near Nashua, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
BROX INDUSTRIES INC
Petroleum · BROX INDUSTRIES INC
HUDSON, NH03051
4.6 mi
PARKER HANNIFIN CORP CHOMERICS DIV
Computers and Electronic Products · PARKER HANNIFIN CORP
HUDSON, NH03051
3.3 mi
MORGAN ADVANCED CERAMICS INC
Chemicals · MORGANITE INDUSTRIES INC
HUDSON, NH03051
6.0 mi
COLT REFINING INC
Primary Metals · NA
MERRIMACK, NH03054
5.8 mi
ANHEUSER-BUSCH LLC (MERRIMACK BREWERY)
Beverages · ANHEUSER-BUSCH COS LLC
MERRIMACK, NH03054
5.4 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of Nashua

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.

Source: EPA Superfund National Priorities List

Environmental Risk

Drought conditions

D2 — severe drought

Hillsborough 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.

1
Weeks at D2+ (current streak)
7.4%
Months in D2+ (last 30y)
1
Weeks at D2+ (last 5y)

Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.

Environmental Risk

Flood & disaster history

9
Declared disasters
Oct 2012
Most recent
Flood
Most common type

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.

Oct 2012
HURRICANE SANDY
Hurricane FEMA #3360
Aug 2011
HURRICANE IRENE
Hurricane FEMA #3333
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3258
Oct 1996
FALL NORTHEASTER RAINSTORM
Flood FEMA #1144
Sep 1991
HURRICANE BOB & SEVERE STORMS
Hurricane FEMA #917
Aug 1990
SEVERE STORMS & FLOODING
Flood FEMA #876

Recommended water filters

Based on contaminants detected in Nashua's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS 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 ND 0.01 µg/L PFAS Not Detected
lithium 11.300 HI µg/L PFAS 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 ND HI µg/L PFAS Not Detected
PFBS 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 ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA 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
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 12.0 ppb from 1992 (12.0 ppb) to 2023 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Surface Water
Operator
Private
Population Served
89,148
Water Systems
2
Source breakdown
Surface Water
1
Groundwater
1
Water Source

Where Nashua's water comes from

Surface Water

Nashua'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 89,148 people through 2 water systems.

Local Hydrology

Water bodies near Nashua

Nashua is located near 4 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.

Souhegan River
river
Nashua River
river
Merrimack River
river
Beaver Brook
river
Infrastructure

Water systems serving Nashua

System Name PWSID Population Source
PENNICHUCK WATER WORKS NH1621010 89,073 SW
FARLEY RD ESTATES NH1622010 75 GW
Regional Comparison

How Nashua compares

Full New Hampshire rankings →

Nashua's score of 88.7/100 is above the average of 64/100 among major New Hampshire cities. It outscores 9 of 10 nearby cities.

Nashua (this city)
88.7
Manchester
50.9
Concord
51.3
Portsmouth
80.7
Keene
89.2
Dover
84
New Hampshire avg
64
City Profile

About Nashua, 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.

Share this reportHelp others learn about their water quality
WhatsAppXFacebookLinkedInEmail

Frequently asked questions

Is Nashua, NH tap water safe to drink?

Nashua's water quality earned a grade of A- (88.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #11 out of 119 cities tested in New Hampshire.

What contaminants are in Nashua's water?

Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 4 violations are on record.

How is Nashua'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 Nashua?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Nashua's water come from?

Nashua's water is sourced from Surface water. The city has 2 water systems serving approximately 89,148 residents.

What health violations has Nashua's water system had?

Nashua has 3 health-based violations on record. The most recent violation was recorded in January 2016. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.

How does Nashua's water compare to other cities?

Nashua ranks #11 out of 119 cities in New Hampshire (better than 91% of state cities) and #3259 out of 15744 cities nationally (79th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.