Is North Stonington, CT 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 ↓
63.2/100
waterverge.com North Stonington, CT — Water Quality Report
North Stonington's drinking water received a grade of C (63.2 out of 100), indicating fair water quality. The city's 3 water systems serve approximately 2,309 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 267 violations on record, including 19 health-based violations. 48 remain unresolved.
What to know about North Stonington's water
North Stonington ranks #61 out of 158 cities in Connecticut for water quality, placing it mid-range in the state.
North Stonington 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, North Stonington may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is North Stonington, CT water safe to drink?
North Stonington's drinking water has significant quality concerns based on EPA testing data. With a grade of C (63.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 2,309 residents using groundwater (wells).
Recent water quality updates for North Stonington
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into North Stonington's water quality assessment. Grade: C (63.2/100).
Contaminants: Lead and Copper Rule.
Contaminants: Lead and Copper Rule.
Contaminants: Lead and Copper Rule.
Key contaminant findings
Based on the most recent EPA sampling data for North Stonington's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
North Stonington's water system has 267 total violations on record, including 19 health-based violations. 48 remain unresolved. 4 violations were issued in the last 5 years.
Where does North Stonington's water come from?
North Stonington's drinking water comes from groundwater (wells), supplied by 3 water systems serving approximately 2,309 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Poquonnock River (river), Shetucket River (river), Yantic River (river).
What North Stonington residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in North Stonington'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.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Recommended water filters
Based on contaminants detected in North Stonington'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. | 2.26 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how North Stonington compares by contaminant
Explore where North Stonington ranks among all Connecticut cities for specific contaminants.
Water source & infrastructure
Where North Stonington's water comes from
North Stonington'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 2,309 people through 3 water systems.
Water bodies near North Stonington
North Stonington is located near 3 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving North Stonington
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SCWA, NORTH STONINGTON DIVISION (NST) | CT1020021 | 1,860 | GW |
| SCWA, CEDAR RIDGE DIVISION | CT1020011 | 370 | GW |
| NORTHSTONE GARDENS | CT1021001 | 79 | GW |
How North Stonington compares
Full Connecticut rankings →North Stonington's score of 63.2/100 is above the average of 47/100 among major Connecticut cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Connecticut rankings →About North Stonington, CT
Wikipedia →Gales Ferry is a census-designated place and village in the town of Ledyard, Connecticut, United States. It is located along the eastern bank of the Thames River. The community developed as a result of having a ferry to Uncasville located at this site, and from which the village was named. Gales Ferry was listed as a census-designated place for the 2010 Census. As of the 2020 census, Gales Ferry had a population of 1,159.
Learn more about your water
Guides and resources related to North Stonington's water quality findings.
Explore water quality across New London
Frequently asked questions
Is North Stonington, CT tap water safe to drink?
North Stonington's water quality earned a grade of C (63.2/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #61 out of 158 cities tested in Connecticut.
What contaminants are in North Stonington's water?
Lead was measured at 0.0 ppb (90th percentile). 267 violations are on record.
How is North Stonington'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 North Stonington?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does North Stonington's water come from?
North Stonington's water is sourced from Groundwater. The city has 3 water systems serving approximately 2,309 residents.
What health violations has North Stonington's water system had?
North Stonington has 19 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. 48 violations remain unresolved.
Is North Stonington's groundwater at risk of contamination?
North Stonington 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 267 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 North Stonington's water compare to other cities?
North Stonington ranks #61 out of 158 cities in Connecticut (better than 61% of state cities) and #11788 out of 15744 cities nationally (25th percentile). The grade of C reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.