Sullivan County, New York: drinking water report. Sullivan County in New York's Catskills region has a population of about 80,000.
Sullivan County in New York's Catskills region has a population of about 80,000. The county relies heavily on small water systems and private wells serving rural and small-town communities. There are no large municipal systems – instead, dozens of small community systems and thousands of individual wells draw from fractured bedrock and glacial deposits. The county's former resorts and camps have left behind legacy contamination at some sites, and agricultural activity in the river valleys adds nutrients to groundwater.
Small-system compliance is the primary regulatory concern in Sullivan County. According to the NYSDOH's 2024 monitoring summary, four community water systems in the county had monitoring or treatment violations during the reporting period – a higher rate per capita than the state average. Small systems operate on limited budgets and may lack the resources for advanced treatment.
New York's strict PFAS MCLs of 10 ppt have flagged contamination in some Sullivan County systems. A 2024 NYSDOH assessment found two small systems in the county with PFAS detections above state limits. The sources are likely diffuse – biosolids, septic systems, and consumer products – rather than military or industrial point sources.
If you are on a private well in Sullivan County, you are your own water utility. No one is testing your water unless you do it yourself. Baseline testing for bacteria, nitrate, and PFAS is a reasonable investment.
Check your water for any available data on public systems in your area. For private wells, our water filter guide includes systems designed for well water with unknown contaminant profiles. Pull your detailed report for any available data, and visit our New York page for statewide context.
Drinking water is one exposure route. These federal datasets also cover Sullivan County, NY.
The EPA places Sullivan County, NY in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
61% of homes in Sullivan County, NY were built before 1980, and 29% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Sullivan County, NY averages 6.2 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide