WaterVerge

Is Windham, NH Tap Water Safe to Drink?

Graded F — but Lead was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

3K residents served 16 water systems PWSID: NH2542030
Overall Score
38.4 / 100
Violations
30 active
Last Updated
May 2026
Source
Groundwater
#101 of 119 in New Hampshire Top 98% nationally
Private
Moderate data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
FGRADE
Water Quality Grade
38.4/100
waterverge.com
F 38.4/100

Windham, NH — Water Quality Report

Windham's drinking water received a grade of F (38.4 out of 100), indicating failing water quality. The city's 16 water systems serve approximately 2,682 residents using groundwater.

Lead levels were measured at 37.0 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 169 violations on record, including 53 health-based violations. 30 remain unresolved.

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

What to know about Windham's water

Windham ranks #101 out of 119 cities in New Hampshire for water quality, placing it among the lowest-rated in the state.

Windham 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, Windham may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.

The system has seen 12 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
38.4 out of 100 Grade F
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
6.4/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
2/20
F
Lead at 37.0 ppb (90th percentile).
Contaminants
17/20
B
PFAS + legacy contaminant analysis.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Windham, NH water safe to drink?

Concerns Identified

Windham's drinking water has significant quality concerns based on EPA testing data. With a grade of F (38.4/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 16 water systems serve approximately 2,682 residents using groundwater (wells).

30
Active Violations
37.0 ppb
Lead (90th %ile)
9 events
Disaster History

Recent water quality updates for Windham

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Windham's water quality assessment. Grade: F (38.4/100).

Violation
2 drinking water violations recorded

Contaminants: Total Haloacetic Acids (HAA5), TTHM.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

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 Windham's water supply.

Lead Exceeds Limit
Detected: 37.0 ppb Limit: 15 ppb (EPA Action Level)

Exceeds EPA action level. Lead service line replacement and point-of-use filtration recommended.

Violation history

Windham's water system has 169 total violations on record, including 53 health-based violations. 30 remain unresolved. 12 violations were issued in the last 5 years.

MRMCLRPTTTOther
Most recent violations:
Jul 2025 Total Haloacetic Acids (HAA5) Resolved
Jul 2025 TTHM Resolved
Apr 2025 Lead and Copper Rule Open
Sep 2024 Lead and Copper Rule Open
Oct 2023 Combined Radium (-226 and -228) 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 Windham's water come from?

Windham's drinking water comes from groundwater (wells), supplied by 16 water systems serving approximately 2,682 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Souhegan River (river), Nashua River (river), Merrimack River (river), Beaver Brook (river).

What Windham residents can do

Install a water filter

Recommended: NSF 53-certified pitcher or under-sink filter. This addresses the specific contaminants found in Windham's water.

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.

Flush your taps

Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.

Monitor alerts during storms

Windham'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
Over Limit
37.0 ppb
EPA Action Level: 15 ppb · +20% over limit
Exceeds LimitFilter: NSF-53
Compliance Record

Violation summary

169
Total violations
53
Health-based
30
Active / unresolved
Jul 2025
Most recent violation
Compliance Record

Violations & advisories

169 Total
30 Active
53 Health-based
139 Resolved
2 SNC
Violations by category
Volatile Organic Chemicals
63
Total Coliform Rule
33
Consumer Confidence Rule
13
Radionuclides and Revised Rad Rule
10
Stage 1 Disinfectants and Disinfection Byproducts Rule
10
Apr 2025 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Sep 2024 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Dec 2020 Active
Revised Total Coliform Rule
Reporting
Reporting 0
Oct 2020 Active
Lead and Copper Rule
Treatment Technique
Health-Based Health 0
Jul 2019 Active
Consumer Confidence Rule
Other Violation 0
Mar 2019 Active
Groundwater Rule
Treatment Technique
Health-Based Health 0
Jul 2018 Active
Consumer Confidence Rule
Other Violation 0
Jul 2018 Active
Consumer Confidence Rule
Other Violation 0
Jul 2017 Active
Consumer Confidence Rule
Other Violation 0
Jul 2017 Active
Consumer Confidence Rule
Other Violation 0
Nov 2015 Active
Public Notice
Other Violation 0
Oct 2015 Active
Public Notice
Other Violation 0
Aug 2015 Active
Groundwater Rule
Treatment Technique
Health-Based Health 0
Jun 2015 Active
Groundwater Rule
Treatment Technique
Health-Based Health 0
Jul 2014 Active
Consumer Confidence Rule
Other Violation 0
Mar 2013 Active
Groundwater Rule
Treatment Technique
Health-Based Health 0
Jul 2012 Active
Consumer Confidence Rule
Other Violation 0
Jul 2012 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Aug 2011 Active
E. COLI
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2011 Active
Consumer Confidence Rule
Other Violation 0
Showing 20 of 169 violations
Environmental Risk

Drought conditions

D2 — severe drought

Rockingham 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.

14
Weeks at D2+ (current streak)
7.7%
Months in D2+ (last 30y)
14
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 Windham's water supply, we recommend the following filter types.

🚰
For Lead
Reverse Osmosis or NSF 53-Certified Pitcher
Lead level (37.0 ppb) exceeds the EPA action level of 15 ppb
Read our guide →

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 37.0 15 ppb Inorganic Over Limit
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has increased by 18.0 ppb from 2007 (19.0 ppb) to 2020 (37.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Private
Population Served
2,682
Water Systems
16
Source breakdown
Groundwater
15
Purchased Surface Water
1
Water Source

Where Windham's water comes from

Groundwater

Windham's drinking water is drawn from underground aquifers through wells.

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 private ownership and serves approximately 2,682 people through 16 water systems.

Local Hydrology

Water bodies near Windham

Windham is located near 4 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

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

Water systems serving Windham

System Name PWSID Population Source
W AND E NH2542030 525 GW
WHISPERING WINDS NH1851020 460 SWP
GOLDEN BROOK NH2542010 323 GW
LAMPLIGHTER VILLAGE NH2542170 162 GW
WARDE REHABILITATION/NURSING NH2544010 155 GW
VILLAGES OF WINDHAM NH2542070 145 GW
FLETCHER CORNER ESTATES NH2542150 133 GW
SPRUCE POND ESTS NH2542180 118 GW
CASTLE REACH NH2542140 115 GW
WINDHAM TERRACE NH2544020 110 GW
HARDWOOD HTS BIRCH HILL NH2542060 100 GW
WOOD MEADOW ESTATES NH2542200 98 GW
HADLEIGH WOODS NH2542160 93 GW
WYNRIDGE CONDOS NH2542080 87 GW
CAMELOT III NH2542190 33 GW
MCAULEY COMMONS NH2542130 25 GW
Regional Comparison

How Windham compares

Full New Hampshire rankings →

Windham's score of 38.4/100 is below the average of 69/100 among major New Hampshire cities. 10 of 10 nearby cities score higher.

Windham (this city)
38.4
Manchester
50.9
Nashua
88.7
Concord
51.3
Portsmouth
80.7
Keene
89.2
New Hampshire avg
69
City Profile

About Windham, 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.

Economic Profile
$171,563
Median Income
$620,378
Median Home Value
$3,125/mo
Median Rent
3.5%
Unemployment
Community
42.1
Median Age
228
People / sq mi
63.6%
College Educated
95.3%
Homeownership
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Frequently asked questions

Is Windham, NH tap water safe to drink?

Windham's water quality earned a grade of F (38.4/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #101 out of 119 cities tested in New Hampshire.

What contaminants are in Windham's water?

Lead was measured at 37.0 ppb (90th percentile). 169 violations are on record.

How is Windham'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 Windham?

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 Windham's water come from?

Windham's water is sourced from Groundwater. The city has 16 water systems serving approximately 2,682 residents.

What health violations has Windham's water system had?

Windham has 53 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 30 violations remain unresolved.

Is Windham's groundwater at risk of contamination?

Windham 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 169 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 Windham's water compare to other cities?

Windham ranks #101 out of 119 cities in New Hampshire (better than 15% of state cities) and #15343 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.