Delaware River Basin (DelR) NAWQA Study Unit

Science Center Objects

The Delaware River Basin (DELR) NAWQA study began in 1997 and is a multi-district effort. Coordinated from our West Trenton, New Jersey office, the study also includes paticipation by our Harrisburg, Pennsylvania and Troy, New York offices. During the first two years of the study (1997-1998) staff was hired, a liaison committee was started, existing data was analyzed, and plans for three years (1999-2001) of intensive data collection were developed. The intensive efforts will include multi-scale study approaches to collect samples of water, suspended and bed sediment, biologic tissues, and aquatic communities. The DELR NAWQA study is then scheduled to enter a low-intensity phase of monitoring and report writing in 2002 and return to another 3 years of intensive study again in 2008-2010.


Advances in the treatment of municipal and industrial waste and changes in manufacturing and processing techniques over the past 25 years have led to improved water quality in many parts of the Delaware River Basin. One indication of this improvement is the return of shad runs to the Delaware River. The presence of toxic compounds, however, still leads to consumption advisories for many fish species, and nutrient loadings adversely affect water quality and the health of ecological communities. Many of the water-quality issues in the Delaware River Basin can be related to the high human population density in the area and related activities associated with urban, industrial, and agricultural land use. Most concerns are related to human health (the quality of domestic water supply, the safety of water contact recreation, and the safety of eating game fish) and the health of ecological communities.

Rafting in the Upper Delaware River

Rafting, canoeing, and fishing are some of the major recreational uses of the upper part of the Delaware River Basin

(Credit: David B. Soete, USGS. Public domain.)

Some of the major water-quality issues that are currently being addressed by water-resource managers in the Delaware River Basin include–

  • Relation of land use to nonpoint sources of contaminants.
  • Effects of natural settings on the distribution, fate, and effects of contaminants in water, sediment, and biota.
  • Relations between streamflow and loadings of nutrients, contaminants, and pathogens.
  • Effects of nutrients and habitat on algae and macrophytes in streams, lakes, and estuaries.
  • Distribution of toxic substances, particularly polychlorinated biphenyls (PCBs), and trace elements in surface water, groundwater, and biota.
  • Presence of human pathogens and pesticides in drinking-water supplies and recreational waters.
  • Effect of dams, impoundments, and diversions on water quality, and on the health of fish and benthic invertebrate communities.
  • Development of management strategies for protecting areas of existing high water quality.
  • Effects of on-lot septic systems and reduced streamflow caused by groundwater withdrawals on water quality and ecological communities.
  • Distribution of natural radioactivity in domestic groundwater supplies.
  • Effects of groundwater/surfacewater interactions on water quality.
  • Effects of coal-mine discharges on water quality and ecological communities.

The Delaware River Basin NAWQA study will characterize spatial and temporal variations in water quality and relate those changes to natural processes and human factors. This scientific characterization can be used by waterresource managers, State and local governments, citizens' groups, and planners as a basis for implementing water-quality management actions and evaluating long-term changes in water quality.


Study Area Description

The Delaware River drainage basin encompasses over 12,000 square miles and includes parts of New York (2,363 mi2), Pennsylvania (6,465 mi2), New Jersey (2,969 mi2), and Delaware (968 mi2) (figure 1). The basin is about 260 miles long from north to south and ranges in width from 40 to 80 miles. About 7.2 million people reside within the study unit boundaries. Surface-water diversions out of the basin supply water to more than 7.0 million additional people in the New York City and northern New Jersey metropolitan areas. The study area covers the entire drainage basin, except for the coastal plain in the state of Delaware and the tidal portions of the Delaware Estuary.

Average annual precipitation ranges from 42 inches in southern New Jersey to about 55 inches in the Catskill Mountains of southern New York; annual snowfall ranges from 13 inches in southern New Jersey to about 50 inches in northwestern New Jersey and southern New York. Generally, precipitation is evenly distributed throughout the year. Annual average temperatures range from 56 degrees Fahrenheit (oF) in southern New Jersey to 50 oF in southern New York.



During the past 25 years, industry and government have made large financial investments in manufacturing, processing, and wastewater-treatment facilities to reduce the amount of contaminants being discharged. Although these investments have led to improved water quality across the Nation, concerns about the effects of nutrients, toxins, and pathogens on human health and that of ecological communities remain. To address the need for consistent and scientifically sound information for managing the Nation's water resources, the U.S. Geological Survey began the National Water-Quality Assessment (NAWQA) program in 1991. This program is unique in that it integrates surface- and groundwater-quality monitoring with the study of aquatic ecosystems. The goals of the NAWQA program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers (water-bearing sediments and rocks), (2) describe how water quality is changing over time, and (3) increase our understanding of the natural and human factors that affect water quality (Leahy and others, 1990, Gilliom and others, 1995).


USGS Study Teams from Delaware/Maryland, New Jersey, New York, and Pennsylvania:

Jeff Fischer - Project Chief (NJ)

Douglas Chichester (PA)

R. Edward Hickman (NJ)

Karen R. Murray (NY)

Paul Dunne (NJ)

Tim Oden (NJ)

Michael D. Bilger (PA)

Robin A. Brightbill (PA)

Susan Edwards (PA)

Kim Orlick (NJ)

Kristin Romanok (NJ)

John Byrnes (NY)

All Data can be found in the Water Resources Data Reports for the following sites and topics:

01411500  Maurice R. @ Norma, NJ
01420500  Beaver Kill @ Cooks Falls
01423000  W. Br. Delaware R. @ Walton, NY
01425000  W. Br. Delaware R. @ Stilesville, NY
01431500  Lackawaxen R. @ Hawley, PA
01432000  Walenpaupack, at dam @ Wilsonville, PA
01434000  Delaware R. @ Port Jervis, NY
01435000  Neversink R. nr Claryville, NY
01437500  Neversink R. nr Godeffroy, NY
01439500  Bush Kill @ Shoemakers, PA
01440000  Flat Brook nr Flatbrookville, NJ
01442500  Broadhead Cr. @ Minisink Hills, PA
01447000  Delaware R. @ Northampton St., Easton, PA
01449000  Lehigh R. @ Lehighton, PA
01451800  Jordan Cr. nr Schnecksville, PA
01454700  Lehigh R. @ Glendon, PA
01457400  Musconetcong R. @ Riegelsville, NJ
01459500  Tohickon Cr. nr Pipersville, PA
01463500  Delaware R. @ Trenton, NJ
01464500  Crosswicks Cr. @ Extonville, NJ
01464907  Little Neshaminy Cr. @ Valley Rd. nr Neshaminy, PA
01465500  Neshaminy Cr. nr Langhorne, PA
01467000  N. Br. Rancocas Cr. @ Pemberton, NJ
01467150  Cooper R. @ Haddonfield, NJ
01470500  Schuylkill R. @ Berne, PA
01470779  TulpeHocken Cr. nr Bernville, PA
01472000  Schuylkill R. @ Pottstown, PA
01472157  French Cr. nr Phoenixville, PA
01473000  Perkiomen Cr. @ Graterford, PA
01474000  Wissahickon Cr., at mouth, Philadelphia, PA
01474500  Schuylkill R. @ Philadelphia, PA
01477120  Raccoon Cr. nr Swedesboro, NJ
01478650  White Clay Cr. @ Newark, DE
01481500  Brandywine Cr. @ Wilmington, DE

Misc QW Fish Collection Results
Trace Elements in Fish Samples
Organochlorine in Fish Samples
Water Quality Miscellaneous Synoptic Sampling
Trace Elements in Streambed Sediment Samples
Organochlorine in Streambed Sediment Samples