New Jersey Ambient Groundwater-Quality Monitoring Network

Science Center Objects

The USGS, in cooperation with the New Jersey Department of Environmental Protection, New Jersey Geological and Water Survey, Ambient Groundwater-Quality Monitoring Net­work (AGWQMN), which is designed to characterize the status of groundwater quality at or near the water table as a function of land use. Shallow groundwater is generally the first and most significantly affected part of the groundwater system, and the quality of this water is related to human activities at the land surface. Additionally, the quality of shallow groundwater is important because it is this water that recharges deeper aquifers used for potable supplies and provides baseflow to local streams and wetlands.

The AGWQMN is a long-term monitoring network with goals to assess the status of groundwater quality by examining the concentrations of various constituents that can be used as environmental indicators, assess water-quality trends by examining data collected on a 3-year cycle, determine the effects of land use on shallow ground-water quality, identify threats from nonpoint sources of contamination, and identify emerging or new environmental issues of concern to the public.

The net­work consists of 150 shallow wells distributed throughout the State of New Jersey among three land-use types. Sixty wells are in agricultural areas, 60 are in urban/suburban areas, and 30 are in undeveloped areas. The State of New Jersey has been subdivided by the NJDEP into five watershed management regions (WMRs) – Passaic, Raritan, Upper Delaware, Lower Delaware, and Atlantic Coastal. These five WMRs are divided into 20 watershed-management areas (WMAs). Beginning in Water Year 1999, approximately 30 sites were sampled in one or several of the five regions every year with a goal of completing the cycle of sampling all 150 wells every 5 years. Beginning in Water Year 2015, the number of wells sampled annually transitioned to 150 wells sampled every 3 years (50 wells sampled per year). Water Year 2017 was the first cycle of collecting water-quality samples at 50 groundwater wells per year.



Samples from the wells are analyzed for field parameters, major ions, nutrients, organic carbon, trace elements, volatile organic compounds, pesticides, gross alpha and gross beta radioactivity, and pre- and polyfluoroalkyl substances (PFAS).



Execpt for PFAS samples, all samples are collected using standard, documented USGS sampling techniques ( to ensure that USGS quality-assurance guidelines are met. The Standard Operating Procedure for PFAS is pending publication.  All data are analyzed, reviewed, and verified before publication.



All data are publicly available at the USGS National Water Information System web site (NWISWeb) at

Current and archived electronic data can be accessed at