Free Connecticut water report: PFAS & lead levels for every water system, worst-affected cities, and EPA violations. Check your ZIP.
Connecticut is a small, densely populated state where approximately 3.6 million residents are packed into just over 5,500 square miles. Drinking water comes primarily from surface reservoirs and groundwater wells, with the state's numerous reservoirs – many built in the 19th and early 20th centuries – serving as the backbone of supply for the major utilities. The Connecticut Water Company and regional water authorities in New Haven, Hartford, and other cities manage systems that serve the majority of the population, while smaller community systems and private wells serve suburban and rural areas.
The Connecticut Department of Public Health (DPH) oversees drinking water quality for approximately 2,500 public water systems. The Long Island Sound watershed, which drains most of the state, has been the focus of decades of water quality work addressing nitrogen loading, industrial discharge, and urban runoff. Connecticut's industrial heritage – brass manufacturing in the Naugatuck Valley, aircraft engines in East Hartford, submarine construction in Groton – has left a legacy of contamination that affects groundwater in specific corridors.
The state's reservoir-based supply is generally well-protected by watershed management programs, but the infrastructure is aging. Many treatment plants and distribution systems date to the mid-20th century or earlier, and the cost of upgrading them falls on a relatively small rate-payer base.
The EPA's UCMR5 monitoring has detected PFAS at public water systems across Connecticut, reflecting the state's mix of military, industrial, and commercial PFAS sources. Manufacturing facilities that used PFAS-containing coatings and treatments, airports where AFFF was deployed, and landfills receiving PFAS-laden waste have all contributed to the contamination picture.
Connecticut has been proactive on PFAS regulation. The state established an action level of 70 ppt for five combined PFAS compounds (PFOA, PFOS, PFHxS, PFNA, and PFHPA) and has been working to adopt enforceable MCLs that align with or go beyond the 2024 federal standards. The Connecticut Department of Energy and Environmental Protection (DEEP) and DPH have coordinated on PFAS investigation and response across the state.
Groundwater contamination is a particular concern in the towns surrounding known PFAS sources. Connecticut's dense development means that contamination plumes from one site can affect multiple water systems and private wells in a relatively small area.
Naval Submarine Base New London in Groton is the most significant military PFAS source in Connecticut. As the primary East Coast submarine base, it has decades of AFFF use history on the installation. The Navy has confirmed PFAS in groundwater on and around the base, and investigations are ongoing to determine the full extent of contamination in surrounding communities.
The base sits along the Thames River and borders the town of Groton, where some residents rely on groundwater wells for their drinking water. The Department of Defense has included Naval Submarine Base New London in its PFAS investigation program and is working with state regulators on monitoring and potential remediation.
Bradley Air National Guard Base in East Granby, adjacent to Bradley International Airport, is another site where AFFF use has led to PFAS investigation. The base shares the airport complex, and firefighting foam used in training exercises has been detected in surrounding groundwater monitoring wells.
Other military and former military sites in Connecticut under PFAS review include the former Naval Air Station Quonset Point's Connecticut-based operations and various National Guard facilities. See our military bases page for the full list.
Connecticut's regulatory framework for PFAS combines drinking water action levels with broader environmental investigation requirements. DPH has required public water systems that detect PFAS above action levels to notify the public and take corrective action, which may include treatment installation or taking sources offline.
The state has also conducted targeted PFAS sampling beyond UCMR5 requirements, focusing on areas near known or suspected contamination sources. DEEP has investigated PFAS at manufacturing facilities, fire training areas, and landfills, generating data that feeds into the broader understanding of where contamination exists.
According to DPH data, approximately 23% of Connecticut residents rely on private wells for their drinking water. This is a significant number for a state this small, and private wells are not subject to PFAS testing requirements under state or federal law. DPH has recommended that private well owners near known contamination sources test for PFAS, but the cost falls on the homeowner.
Connecticut's participation in UCMR5 has added to the state's PFAS dataset, confirming detections at systems that had not previously been tested and in some cases revealing contamination at unexpected locations.
For a detailed explanation of PFAS compounds and their health effects, see our PFAS guide.
Connecticut's small size means that contamination sources are never far from population centers. The good news is that the state's regulatory response has been relatively aggressive.
1. Check your ZIP code at the homepage to see available monitoring data for your water system. We compile UCMR5, state DPH, and utility data in one place. 2. If you are near Naval Submarine Base New London, Bradley Air National Guard Base, or any known industrial PFAS source, and you rely on a private well, testing is strongly recommended. PFAS lab tests cost $200-400. 3. For systems or wells with confirmed PFAS, a reverse osmosis or activated carbon filter rated for PFAS removal is the most effective household step. Our water filter guide breaks down which certifications matter. 4. Request a detailed water report for your address to see historical data and trends for your specific area.
Connecticut has better PFAS data than many states and is moving toward stricter standards. Check your specific location to see what the data shows for your water supply.