WaterVerge

Is New London, CT Tap Water Safe to Drink?

Graded C- — but Copper and Chlorate were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

46K residents served 4 water systems PWSID: CT0950011
Overall Score
55 / 100
Violations
48 active
Last Updated
May 2026
Source
Surface water
#83 of 158 in Connecticut Top 80% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
C-GRADE
Water Quality Grade
55/100
waterverge.com
C- 55/100

New London, CT — Water Quality Report

New London's drinking water received a grade of C- (55 out of 100), indicating poor water quality. The city's 4 water systems serve approximately 45,678 residents using surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 307 violations on record, including 16 health-based violations. 48 remain unresolved.

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

What to know about New London's water

New London ranks #83 out of 158 cities in Connecticut for water quality, placing it below average 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.

Hexavalent chromium (chromium-6) was detected at 0.09 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.

The system has seen 9 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
55 out of 100 Grade C-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
11.2/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
16/20
B
Lead at 0.0 ppb (90th percentile).
Contaminants
15.9/20
B
No PFAS compounds detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Surface water.
Water Safety

Is New London, CT water safe to drink?

Concerns Identified

New London's drinking water has significant quality concerns based on EPA testing data. With a grade of C- (55/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 45,678 residents using surface water (rivers, lakes, or reservoirs).

48
Active Violations
0.0 ppb
Lead (90th %ile)
None
PFAS Detected

Recent water quality updates for New London

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into New London's water quality assessment. Grade: C- (55/100).

Violation
2 drinking water violations recorded

Contaminants: Consumer Confidence Rule.

Violation
2 drinking water violations recorded

Contaminants: Consumer Confidence Rule.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Key contaminant findings

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

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

Well within EPA limits.

Copper Exceeds Limit
Detected: 3.24 mg/L Limit: 1.3 mg/L (EPA Action Level)

Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.

Violation history

New London's water system has 307 total violations on record, including 16 health-based violations. 48 remain unresolved. 9 violations were issued in the last 5 years.

OtherMRMONMCLTT
Most recent violations:
Jul 2025 Consumer Confidence Rule Open
Jul 2025 Consumer Confidence Rule Open
Jul 2024 Consumer Confidence Rule Open
Jul 2024 Consumer Confidence Rule Open
Dec 2023 Lead and Copper Rule Open

Where does New London's water come from?

New London's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 4 water systems serving approximately 45,678 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Poquonnock River (river), Bride Brook Nr East Lyme (river).

What New London residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in New London'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.

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
Copper (90th percentile)
Inorganic
Over Limit
3.24 mg/L
EPA Action Level: 1.3 mg/L · +20% over limit
Exceeds Limit
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
25.2 µg/L
EPA MCL: 60 µg/L · 42% of limit
Within LimitUCMR 4 DataHAA6Br: 4.9 µg/LHAA9: 30.1 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
0.09 µg/L
CA MCL (no federal MCL): 10 µg/L · 1% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
39.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 3% of limit
DetectedUCMR 3 Data
Manganese
Inorganic
Detected
2.0 µg/L
EPA Secondary MCL: 50 µg/L · 4% of limit
DetectedUCMR 4 Data
Chlorate
Disinfection Byproduct
Over HA
440.0 µg/L
EPA Lifetime HA: 210 µg/L · +20% over limit
Over Health AdvisoryUCMR 3 Data
PFAS Testing

Forever chemicals overview

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

Violation summary

307
Total violations
16
Health-based
48
Active / unresolved
Jul 2025
Most recent violation
Compliance Record

Violations & advisories

307 Total
48 Active
16 Health-based
259 Resolved
1 SNC
Violations by category
Volatile Organic Chemicals
58
Stage 1 Disinfectants and Disinfection Byproducts Rule
53
Total Coliform Rule
40
Consumer Confidence Rule
35
Synthetic Organic Chemicals
34
Jul 2025 Active
Consumer Confidence Rule
Other Violation 0
Jul 2025 Active
Consumer Confidence Rule
Other Violation 0
Jul 2024 Active
Consumer Confidence Rule
Other Violation 0
Jul 2024 Active
Consumer Confidence Rule
Other Violation 0
Dec 2023 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2023 Active
Consumer Confidence Rule
Other Violation 0
Jul 2023 Active
Consumer Confidence Rule
Other Violation 0
Dec 2020 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Oct 2017 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Aug 2017 Active
Consumer Confidence Rule
Other Violation 0
Aug 2017 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
Aug 2016 Active
Consumer Confidence Rule
Other Violation 0
Oct 2015 Active
Public Notice
Other Violation 0
Aug 2014 Active
Consumer Confidence Rule
Other Violation 0
Jul 2014 Active
Consumer Confidence Rule
Other Violation 0
Aug 2012 Active
Consumer Confidence Rule
Other Violation 0
Jul 2012 Active
Consumer Confidence Rule
Other Violation 0
Oct 2011 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Showing 20 of 307 violations
Industrial pollution

Top industrial polluters within 10 miles of New London

Industrial polluters nearby

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

Total reported releases to surface water: 54 lbs

FacilityTop chemicalTo surface water (lbs/yr)Distance
ELECTRIC BOAT CORP
Transportation Equipment · GENERAL DYNAMICS CORP
GROTON, CT06340
Copper compounds321.3 mi
DONCASTERS INC PRECISION CASTINGS NEW ENGLAND
Primary Metals · DONCASTERS LTD
GROTON, CT06340
Cobalt152.4 mi
AMERICAS STYRENICS ALLYNS POINT PLANT
Chemicals · AMERICAS STYRENICS LLC
GALES FERRY, CT06335
Zinc compounds77.5 mi
MONTVILLE POWER LLC
Electric Utilities · ARCLIGHT ENERGY PARTNERS
UNCASVILLE, CT06382
Polycyclic aromatic compounds06.6 mi
PCC STRUCTURALS
Primary Metals · BERKSHIRE HATHAWAY INC
GROTON, CT06340
Chromium02.4 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of New London

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

Recommended water filters

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

🔧
For Copper
Reverse Osmosis or KDF Filter
Copper exceeds the EPA action level of 1.3 mg/L

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
Copper (90th percentile) 3.24 1.3 mg/L Inorganic Over Limit
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 ND HI µg/L PFAS Not 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 13.0 ppb from 1992 (13.0 ppb) to 2025 (0.0 ppb).

Copper level trend (90th percentile)

EPA action level: 1.3 mg/L
Copper has increased by 0.780 mg/L from 1993 (2.460 mg/L) to 2000 (3.240 mg/L).
Infrastructure

Water source & infrastructure

Primary Source
Surface Water
Operator
Local Government
Population Served
45,678
Water Systems
4
Source breakdown
Purchased Surface Water
2
Surface Water
1
Groundwater
1
Water Source

Where New London's water comes from

Surface Water

New London'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 local government ownership and serves approximately 45,678 people through 4 water systems.

Local Hydrology

Water bodies near New London

New London is located near 2 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.

Poquonnock River
river
Bride Brook Nr East Lyme
river
Infrastructure

Water systems serving New London

System Name PWSID Population Source
NEW LONDON DEPT. OF PUBLIC UTILITIES CT0950011 27,620 SW
WATERFORD WPCA CT1520071 16,578 SWP
MONTVILLE WATER SUPPLY CT0864011 1,300 SWP
WATERFORD COUNTRY SCHOOL, INC. CT1520061 180 GW
Regional Comparison

How New London compares

Full Connecticut rankings →

New London's score of 55/100 is above the average of 47/100 among major Connecticut cities. It outscores 7 of 10 nearby cities.

New London (this city)
55
Ansonia
49.4
Ansonia
33.5
Ansonia
34.5
Berlin
41
Connecticut avg
47
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Frequently asked questions

Is New London, CT tap water safe to drink?

New London's water quality earned a grade of C- (55/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #83 out of 158 cities tested in Connecticut.

What contaminants are in New London's water?

Lead was measured at 0.0 ppb (90th percentile). No PFAS compounds were detected. 307 violations are on record.

How is New London'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 New London?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does New London's water come from?

New London's water is sourced from Surface water. The city has 4 water systems serving approximately 45,678 residents.

What health violations has New London's water system had?

New London has 16 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. 48 violations remain unresolved.

How does New London's water compare to other cities?

New London ranks #83 out of 158 cities in Connecticut (better than 47% of state cities) and #12562 out of 15744 cities nationally (20th percentile). The grade of C- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.