Is Old Lyme, CT Tap Water Safe to Drink?
Graded D — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
46/100
waterverge.com Old Lyme, CT — Water Quality Report
Old Lyme's drinking water received a grade of D (46 out of 100), indicating poor water quality. The city's 11 water systems serve approximately 4,823 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 778 violations on record, including 42 health-based violations. 132 remain unresolved.
What to know about Old Lyme's water
Old Lyme ranks #111 out of 158 cities in Connecticut for water quality, placing it below average in the state.
Old Lyme 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.
The system has seen 93 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Old Lyme, CT water safe to drink?
Old Lyme's drinking water has significant quality concerns based on EPA testing data. With a grade of D (46/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 11 water systems serve approximately 4,823 residents using groundwater (wells).
Recent water quality updates for Old Lyme
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Old Lyme's water quality assessment. Grade: D (46/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Consumer Confidence Rule.
Contaminants: Public Notice.
Key contaminant findings
Based on the most recent EPA sampling data for Old Lyme'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
Old Lyme's water system has 778 total violations on record, including 42 health-based violations. 132 remain unresolved. 93 violations were issued in the last 5 years.
Where does Old Lyme's water come from?
Old Lyme's drinking water comes from groundwater (wells), supplied by 11 water systems serving approximately 4,823 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Indian River (river).
What Old Lyme residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Old Lyme'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 Old Lyme'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. | 2.81 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Old Lyme compares by contaminant
Explore where Old Lyme ranks among all Connecticut cities for specific contaminants.
Water source & infrastructure
Where Old Lyme's water comes from
Old Lyme'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 4,823 people through 11 water systems.
Water bodies near Old Lyme
Old Lyme is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Old Lyme
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CTWC - SHORELINE REGION-SOUND VIEW | CT1050732 | 3,028 | GW |
| CTWC - SHORELINE REGION-POINT O WOODS | CT1050752 | 1,068 | GW |
| CHADWICK HOMEOWNERS ASSN., INC. | CT1050011 | 292 | GW |
| WHISPERING PINES MHP | GA3050030 | 94 | GW |
| RYE FIELD MANOR ELDERLY HOUSING | CT1056241 | 78 | GW |
| MILE CREEK APARTMENTS | CT1050131 | 60 | GW |
| LYMEWOOD ELDERLY HOUSING | CT1056221 | 50 | GW |
| LYME ACADEMY APARTMENTS,LLC | CT1059251 | 48 | GW |
| LAUREL HEIGHTS ASSOCIATION, INC. | CT1056231 | 45 | GW |
| LYME REGIS, INC. | CT1050141 | 32 | GW |
| BOXWOOD CONDOMINIUM ASSOCIATION | CT1051011 | 28 | GW |
How Old Lyme compares
Full Connecticut rankings →Old Lyme's score of 46/100 is on par with the average of 47/100 among major Connecticut cities. It outscores 6 of 10 nearby cities.
Nearby cities
View Connecticut rankings →About Old Lyme, CT
Wikipedia →Clinton is a town in Middlesex County, Connecticut, United States. The town is part of the Lower Connecticut River Valley Planning Region. The population of the town was 13,185 at the 2020 census. The town center along the shore line was listed as a census-designated place (CDP) by the U.S. Census Bureau in the 2020 census.
Learn more about your water
Guides and resources related to Old Lyme's water quality findings.
Explore water quality across New London
Frequently asked questions
Is Old Lyme, CT tap water safe to drink?
Old Lyme's water quality earned a grade of D (46/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #111 out of 158 cities tested in Connecticut.
What contaminants are in Old Lyme's water?
Lead was measured at 0.0 ppb (90th percentile). 778 violations are on record.
How is Old Lyme'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 Old Lyme?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Old Lyme's water come from?
Old Lyme's water is sourced from Groundwater. The city has 11 water systems serving approximately 4,823 residents.
What health violations has Old Lyme's water system had?
Old Lyme has 42 health-based violations on record. The most recent violation was recorded in August 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 132 violations remain unresolved.
Is Old Lyme's groundwater at risk of contamination?
Old Lyme 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 778 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 Old Lyme's water compare to other cities?
Old Lyme ranks #111 out of 158 cities in Connecticut (better than 30% of state cities) and #13961 out of 15744 cities nationally (11th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.