A Historical Look at Changing Water Quality in the Delaware River Basin

Fact Sheet 2020-3007
Integrated Water Availability Assessments Program
By:  and 


  • Document: Report (pdf)
  • Data Release: USGS data release – Water-quality trends and trend component estimates for the Nation's rivers and streams using Weighted Regressions on Time, Discharge, and Season (WRTDS) models and generalized flow normalization, 1972–2012
  • Download citation as: RIS | Dublin Core


In 2019 the U.S. Geological Survey (USGS) launched a pilot regional Integrated Water Availability Assessment (IWAA) in the Delaware River Basin (fig. 1). IWAA is intended to explore, test, and refine systems and processes for assessing water availability for human and ecological uses and understanding their underlying controls. Water quality plays an important role in supporting ecological health and determining the suitability of water for human consumption, recreation, agriculture, and industry. Understanding how water quality has changed over time in response to natural and human-induced changes in landscape and climate identifies potential challenges in safeguarding water for all uses. The USGS has evaluated water-quality trends across the Nation, and 22 of the evaluated sites are in the Delaware River Basin. These 22 sites are in the Appalachian Plateau, Valley and Ridge, Piedmont, and Coastal Plain Physiographic Provinces. Data from these sites indicate decadal to multidecadal changes in water quality and provide an initial look at how nutrient concentrations, such as total phosphorous, total nitrogen, and nitrate, and salinity indicators, such as specific conductance, sulfate, and chloride, have varied over time in the basin. The time period of the evaluation ranged from 1972 to 2012.

Suggested Citation

Murphy, J.C., and Shoda, M.E., 2020, A historical look at changing water quality in the Delaware River basin: U.S. Geological Survey Fact Sheet 2020–3007, 2 p., https://doi.org/10.3133/fs20203007.

ISSN: 2327-6932 (online)

Study Area

Table of Contents

  • Changes in Water Quality Through 2012
  • Nutrient Runoff
  • Potential Corrosivity
  • Effects of Water Quality on Water Availability
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title A historical look at changing water quality in the Delaware River basin
Series title Fact Sheet
Series number 2020-3007
DOI 10.3133/fs20203007
Year Published 2020
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Ohio-Kentucky-Indiana Water Science Center, WMA - Earth System Processes Division
Description Report: 2 p.; Data Release
Country United States
State Delaware, New Jersey, New York, Pennsylvania
Other Geospatial Delaware River basin
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details