National Water-Quality Assessment (NAWQA) Program Studies in New Jersey

Science Center Objects

The USGS National Water-Quality Assessment Project (NAWQA) is now part of the USGS National Water-Quality Program (NWQP). NAWQA provides nationally consistent data and information on the quality of the Nation’s water. Studies provide information on current water-quality conditions, a baseline for trend evaluation, and an understanding of what factors affect water quality. Groundwater studies for the NAWQA program provide information on the quality of water in shallow monitoring wells, domestic-supply wells, and public-supply wells. The data collected from surface water samples will be used in a national context to describe water quality characteristics of rivers and streams influenced by various land uses (urban, agricultural, and reference).

Map of New Jersey's geology

Geological Map of New Jersey

(Public domain.)

In 1991, Congress established the National Water-Quality Assessment (NAWQA) to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has been a leading source of scientific data and knowledge used by national, regional, state, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs.

NAWQA studies have been conducted during decadal cycles:

  • Cycle I: 1991-2001
  • Cycle II: 2002-2012
  • Cycle III: 2013-2023

NAWQA Cycle 3 has the followig science goals:

  • Goal 1 –Assess the current quality of the Nation’s freshwater resources and how water quality is changing over time (Status and Trends)
  • Goal 2 – Continuing: Evaluate how human activities and natural factors, such as land use and climate change, are affecting the quality of surface water and groundwater (Understanding Causes)
  • Goal 3 –Determine the effects of contaminants, excess nutrients, sediment, and streamflow alteration on aquatic ecosystems (Understanding Effects)
  • Goal 4 –Predict the effects of human activities, climate change, and management strategies on water quality and ecosystem condition (Forecasting)


Groundwater Studies

As part of the NWQP, groundwater quality is being characterized in 20 of the nation’s 68 Principle aquifers, including the Northern Atlantic Coastal Plain aquifer system underlying  southern New Jersey.  NAWQA studies of Groundwater quality – Current Conditions and Changes Through Time include Land Use Studies (LUS), Major Aquifer Studies (MAS), and Principal Aquifer Studies (PAS). These three study types are based on sampling networks of wells distributed across an area of interest.

  • LUS networks typically consist of observation wells that are relatively shallow;
  • MAS networks typically consist of domestic-supply wells that are intermediate in depth; and
  • PAS networks typically consist of public-supply wells that are relatively deep.

As part of NAWQA Cycle III, USGS scientists collect and record both water levels and water quality data on local groundwater through well networks and collect samples within LUS, MAS, and PAS network within the Kirkwood-Cohansey aquifer system.

The Decadal Change in Groundwater Quality web-mapping application shows how concentrations of pesticides, nutrients, metals, and organic contaminants in groundwater are changing during decadal periods across the Nation. Site information and data are available here: 


Fish Shocking on the Bound Brook

USGS Scientists Jonathan Kennen, Tim Reilley, Jason Schvansa, and Dan Skulski fish shocking for a NAWQA Ecology study on the Bound Brook at Middlesex, New Jersey (USGS Site ID 01403900) during Cycle 2, 2008

(Public domain.)

Surface-Water Studies

NAWQA characterizes the status and trends of water quality and aquatic ecosystems by monitoring ambient water-quality and ecological conditions through the newly established National Water Quality Network (NWQN) for Rivers and Streams. The NWQN is the primary source of data for the systematic annual reporting of ambient conditions nationally. The new NWQN includes 22 large river coastal sites, 41 large river inland sites, 30 wadeable stream reference sites, 10 wadeable stream urban sites, and 10 wadeable stream agricultural sites.



    Two NWQN sites are currently monitored in New Jersey:

    The large coastal river site Delaware River at Trenton, NJ (USGS Site ID 01463500). Water-quality samples are collected from this site 14 times per year and analyzed for: 

    • Field Parameters such as pH, specific conductance, dissolved oxygen and turbidity
    • Nutrients (nitrogen and phosphorus species)
    • Chloride and sulfate
    • Total dissolved solids
    • Dissolved organic and inorganic carbon
    • Selected trace elements
    • Suspended sediment
    • Pesticides


    The reference site McDonalds Branch in Byrne State Forest, NJ (USGS Site ID 01466500). Ecological samples are collected at this site once per year in August and the data is available online at the USGS BioData website. Water-quality samples are collected from this site 18 times per year and analyzed for:

    • Field Parameters such as pH, specific conductance, dissolved oxygen and turbidity
    • Nutrients (nitrogen and phosphorus species)
    • Chloride and sulfate
    • Dissolved organic carbon
    • Selected trace elements