Is Winchester, NH Tap Water Safe to Drink?
Graded C- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
59.5/100
waterverge.com Winchester, NH — Water Quality Report
Winchester's drinking water received a grade of C- (59.5 out of 100), indicating poor water quality. The city's 3 water systems serve approximately 3,067 residents using groundwater.
Lead data is not currently available for this system. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 62 violations on record, including 6 health-based violations. 10 remain unresolved.
What to know about Winchester's water
Winchester ranks #69 out of 119 cities in New Hampshire for water quality, placing it below average in the state.
Winchester 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.
As a small community water system, Winchester may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 25 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Winchester, NH water safe to drink?
Winchester's drinking water has significant quality concerns based on EPA testing data. With a grade of C- (59.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 3,067 residents using groundwater (wells).
Recent water quality updates for Winchester
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Winchester's water quality assessment. Grade: C- (59.5/100).
Contaminants: Lead and Copper Rule.
Contaminants: 1,2-Dichloroethane, p-Dichlorobenzene, 1,1,2-Trichloroethane.
Contaminants: Public Notice, Lead and Copper Rule.
Federal disaster declaration (FEMA DR-4740). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4624). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Winchester's water supply.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Winchester's water system has 62 total violations on record, including 6 health-based violations. 10 remain unresolved. 25 violations were issued in the last 5 years.
Flood & environmental risk
Cheshire County has experienced 10 federally declared disasters since 1986. 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 Ashuelot River Above The Branch,, Ashuelot River, Connecticut River.
Where does Winchester's water come from?
Winchester's drinking water comes from groundwater (wells), supplied by 3 water systems serving approximately 3,067 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Ashuelot River Above The Branch, (river), Ashuelot River (river), Connecticut River (river).
What Winchester residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Winchester'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.
Winchester'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
D1 — moderate droughtCheshire County is currently in D1 (moderate 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
Cheshire County has experienced 10 federally declared disasters since 1986. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Winchester's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| 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. | 1.51 | 1.3 | mg/L | Inorganic | Over Limit |
Copper level (90th percentile)
Latest reading: 1.510 mg/L (1993)
EPA action level: 1.3 mg/L
See how Winchester compares by contaminant
Explore where Winchester ranks among all New Hampshire cities for specific contaminants.
Water source & infrastructure
Where Winchester's water comes from
Winchester'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 local government ownership and serves approximately 3,067 people through 3 water systems.
Water bodies near Winchester
Winchester is located near 3 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Winchester
| System Name | PWSID | Population | Source |
|---|---|---|---|
| WINCHESTER WATER DEPT | NH2531010 | 2,800 | GW |
| SOUTH PARRISH | NH2533010 | 140 | GW |
| GREEN VALLEY MOBILE HOME PARK | NH2533020 | 127 | GW |
How Winchester compares
Full New Hampshire rankings →Winchester's score of 59.5/100 is below 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 Winchester, NH
Wikipedia →Winchester is a town in Cheshire County, New Hampshire, United States. The population was 4,150 at the 2020 census. The primary community in the town, where 1,606 people resided at the 2020 census, is defined by the U.S. Census Bureau as the Winchester census-designated place (CDP). The town also includes the village of Ashuelot and part of Pisgah State Park.
Learn more about your water
Guides and resources related to Winchester's water quality findings.
Explore water quality across Cheshire
Frequently asked questions
Is Winchester, NH tap water safe to drink?
Winchester's water quality earned a grade of C- (59.5/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #69 out of 119 cities tested in New Hampshire.
What contaminants are in Winchester's water?
62 violations are on record.
How is Winchester'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 Winchester?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Winchester's water come from?
Winchester's water is sourced from Groundwater. The city has 3 water systems serving approximately 3,067 residents.
What health violations has Winchester's water system had?
Winchester has 6 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. 10 violations remain unresolved.
Is Winchester's groundwater at risk of contamination?
Winchester 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 62 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 Winchester's water compare to other cities?
Winchester ranks #69 out of 119 cities in New Hampshire (better than 42% of state cities) and #12173 out of 15744 cities nationally (23th percentile). The grade of C- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.