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Water Quality Assessment Reports
Delaware River and Bay Water Quality Assessment Reports Overview

Every two years, the DRBC compiles a Delaware River and Bay Water Quality Assessment Report for the U.S. EPA, which provides an assessment of the Delaware River and Bay's support of various uses during previous years. The uses, which are protected by the DRBC's Water Quality Regulations (pdf 4 MB) or by the federal Clean Water Act of 1972, are:

  • Maintenance of aquatic life
  • Providing a raw water source for human consumption
  • Swimming and recreation
  • Fish consumption
  • Shellfish consumption

The assessment primarily involves comparing levels of key water quality indicators (pH, for example) with DRBC stream quality objectives, identifying impaired waters, or those that do not meet DRBC's water quality regulations. The regulations define "zones" in the Delaware River (pdf 1.4 MB) to which the stream quality objectives are applied, and the report assesses water quality based in part upon those zones.

Data used for the report come from a variety of sources. The foundation for the assessment comes from DRBC's three water quality monitoring programs that cover different sections of the Delaware River:

  • Scenic Rivers Monitoring Program (From Hancock, N.Y. to the Delaware Water Gap)
  • Lower Delaware Monitoring Program (from the Delaware Water Gap to Trenton, N.J.)
  • Delaware Estuary Boat Run Program (from Trenton, N.J. to the mouth of the Delaware Bay)

In addition, data from a variety of other sources were utilized in making the water quality assessments. These other sources include:

  • U.S. Geological Survey National Water Information System
  • Pennsylvania Department of Environmental Protection (DEP) Water Quality Network
  • New York State Department of Environmental Conservation Ambient Water Quality Monitoring Program
  • New Jersey DEP Ambient Surface Water Monitoring Program
  • U.S. Environmental Protection Agency's (EPA) National Coastal Assessment Program

The biennial reporting of water quality assessments of the Delaware River and Bay is intended to provide the U.S. EPA and the public with an overview of water quality conditions and to provide a basis for further study. More intensive studies and analyses are needed for focusing in on site-specific issues.

2016 Delaware River and Bay Water Quality Assessment

2016 Final Report:

Archived Delaware River and Bay Water Quality Assessment Reports (2014-1998)

2014 Final Report:

2012 Final Report:

2010 Assessment Methodology and Final Report:

Through coordination with our state and federal partners, DRBC identified several areas where we proposed to employ a different methodology in performing the assessment for 2010 than what was used in the past. The assessment methodology used to develop the 2010 Assessment was noticed in the Federal Register on June 24, 2009, available on the DRBC web site in July 2009, and finalized in November 2009.

2008 Assessment Report:

Delaware River and Bay Water Quality Assessment Report (pdf 1.2 MB; submitted to the U.S. EPA in April 2008)

2006 Assessment Report:

Delaware River and Bay Water Quality Assessment Report (pdf 2.6 MB; submitted to the U.S. EPA in October 2006)

2004 Assessment Report:

Consistent with the U.S. EPA's Guidance for the 2004 Assessment, Listing and Reporting Requirements Pursuant to Sections 303(d) and 305(b) of the Clean Water Act (July 21, 2003), assessed water bodies are placed into one of five categories:

  • Category 1: All designated uses are met
  • Category 2: Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met
  • Category 3: Insufficient data to determine whether any designated uses are met
  • Category 4: Water is impaired or threatened but a TMDL is not needed (see Section II E of this document)
  • Category 5: Water is impaired or threatened and a TMDL is needed

The report also describes the methodology utilized to assign water bodies to the categories.

Delaware River and Bay Water Quality Assessment Report (pdf 3.8 MB; submitted to the U.S. EPA in September 2004)

2002 Assessment Report:

Consistent with the U.S. EPA's Guidelines for Preparation of the Comprehensive State Water Quality Assessments [305(b) Reports] and Electronic Updates (September 1997), assessed water bodies are categorized into one of four use support levels:

  • Fully supporting the use;
  • Fully supporting the use, but the use is threatened;
  • Partially supporting the use; and
  • Not supporting the use

The report also describes the methodology utilized to assign water bodies to use support categories.

Delaware River and Bay Water Quality Assessment Report (pdf 3.86 MB; submitted to the U.S. EPA in September 2002, revised April 2003)

2000 Assessment Report:

Delaware River and Bay Water Quality Assessment Report (pdf 1.4 MB; submitted to the U.S. EPA in August 2000)

1998 Assessment Report:

Delaware River and Bay Water Quality Assessment Report (pdf 1.4 MB; submitted to the U.S. EPA in August 1998)