Chittenden County, Vermont: drinking water report. Chittenden County is Vermont's most populous county, with about 168,000 residents including Burlington.
Chittenden County is Vermont's most populous county, with about 168,000 residents including Burlington. The Champlain Water District draws from Lake Champlain, serving most of the county's population. The lake has been under increasing ecological pressure from agricultural runoff, urban stormwater, and legacy contamination – issues that affect both the lake's ecology and the drinking water drawn from it.
Lake Champlain's phosphorus problem has worsened over the past decade. According to the Lake Champlain Basin Program's 2024 monitoring data, total phosphorus in Missisquoi Bay exceeded 100 ug/L during summer – over six times the target level. Burlington's intake in the broader lake is less affected, but cyanobacterial blooms have been detected near the intake during late summer, requiring enhanced treatment.
The former Burlington International Airport has confirmed PFAS contamination. Vermont DEC's 2024 investigation found PFOS at 30 ppt in monitoring wells near the airport's fire training area. The contamination has affected private wells in the Winooski area east of the airport. A 2024 DEC compliance report noted that the Champlain Water District's treated water showed PFAS at 4 ppt – below the state standard but detectable.
Burlington's Lake Champlain water supply is thoroughly treated and meets all standards. The primary household concerns are algal blooms during late summer (which treatment addresses) and trace PFAS that is difficult to remove completely at the plant level.
Check your water for current data. For PFAS and potential algal byproducts, reverse osmosis at the kitchen tap provides the most comprehensive household protection. Our water filter guide covers lake-water-appropriate systems. Pull your detailed report for seasonal patterns, and visit our Vermont page for statewide data.