Ambient Groundwater Quality Monitoring in New York

The Ambient Groundwater Quality Monitoring Project is an ongoing cooperative effort between the U.S. Geological Survey (USGS) and the New York State Department of Environmental Conservation (NYSDEC). The objective is to quantify, understand, and report on ambient groundwater quality in aquifers across New York. The project began in 2002, and all data are publicly accessible through USGS Water Data for the Nation, as well as through USGS reports and USGS data releases linked on this webpage.

In spring 2024, USGS and NYSDEC began the first comprehensive statewide groundwater quality analysis that combined the upstate New York dataset (nearly 900 wells sampled) with USGS-collected groundwater quality data from Long Island (nearly 200 wells sampled) to better understand the quality of groundwater used for drinking water across New York State. The analysis focused on the factors affecting the occurrence and distribution of constituents statewide, with particular attention to those of regional or statewide public health concern. Based on the findings, the program was redesigned to assess the impacts of land use on the groundwater quality of shallow unconfined aquifers. The goals of the program may continue to change based on ongoing findings and changing priorities. 

The redesigned Ambient Groundwater Monitoring Program consists of two networks; each sampled once every five years:

• Statewide Network — An unfixed network of 150 shallow, unconfined wells, randomly selected each cycle and stratified equally by land use: 50 wells in areas dominated by agriculture, 50 in areas dominated by development, and 50 in all remaining areas.
• Trend Network — A fixed network of 50 unconfined public water-supply wells and springs.

Well locations in the Statewide Network rotate every five-year cycle, while locations in the Trend Network remain constant across cycles. Sampling will resume in summer 2026, with water samples analyzed for more than 100 constituents, including physical parameters, nutrients, major ions, trace elements, total organic carbon, volatile organic compounds, pesticides, and several contaminants of emerging concern (CECs), such as PFAS compounds and 1,4-dioxane