USGS

 

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 02-4076


Changes in Ground-Water Quality in the Canal Creek Aquifer Between 1995 and 2000-2001, West Branch Canal Creek Area, Aberdeen Proving Ground, Maryland

By Daniel J. Phelan, William B. Fleck, Michelle M. Lorah, and Lisa D. Olsen

 

This report is available as a pdf.

 

ABSTRACT

Since 1917, Aberdeen Proving Ground, Maryland has been the primary chemical-warfare research and development center for the U.S. Army. Ground-water contamination has been documented in the Canal Creek aquifer because of past disposal of chemical and ordnance manufacturing waste. Comprehensive sampling for volatile organic compounds in ground water by the U.S. Geological Survey in the West Branch Canal Creek area was done in June-October 1995 and June-August 2000. The purpose of this report is (1) to compare volatile organic compound concentrations and determine changes in the ground-water contaminant plumes along two cross sections between 1995 and 2000, and (2) to incorporate data from new piezometers sampled in spring 2001 into the plume descriptions.

Along the southern cross section, total concentrations of volatile organic compounds in 1995 were determined to be highest in the landfill area east of the wetland (5,200 micrograms per liter), and concentrations were next highest deep in the aquifer near the center of the wetland (3,300 micrograms per liter at 35 feet below land surface). When new piezometers were sampled in 2001, higher carbon tetrachloride and chloroform concentrations (2,000 and 2,900 micrograms per liter) were detected deep in the aquifer 38 feet below land surface, west of the 1995 sampling. A deep area in the aquifer close to the eastern edge of the wetland and a shallow area just east of the creek channel showed declines in total volatile organic compound concentrations of more than 25 percent, whereas between those two areas, concentrations generally showed an increase of greater than 25 percent between 1995 and 2000.

Along the northern cross section, total concentrations of volatile organic compounds in ground water in both 1995 and 2000 were determined to be highest (greater than 2,000 micrograms per liter) in piezometers located on the east side of the section, farthest from the creek channel, and concentrations were progressively lower at piezometer locations closer to the creek channel. Total volatile organic compound con-centrations increased more than 25 percent in some areas in the middle depths of the aquifer; however, it could not be determined if a defined plume was moving farther downgradient along ground-water flow paths toward the creek channel, or vertically downward because of density differences within the aquifer.

 

TABLE OF CONTENTS

Abstract

Introduction

Purpose and scope

Description of study area

Hydrogeologic setting

Site history

Description of contaminant plumes and potential source areas

Previous investigations

Acknowledgments

Methods of investigation

Changes in ground-water quality between 1995 and 2000ĘC2001

Comparison of maximum concentrations

Distribution of volatile organic compounds

Section A-A"

Total volatile organic compounds (VOCs)

1,1,2,2ĘCTetrachloroethane (TeCA)

Trichloroethene (TCE)

Carbon tetrachloride (CT)

Chloroform (CF)

Section C-C'

Total volatile organic compounds (VOCs)

1,1,2,2 Tetrachloroethane (TeCA)

Trichloroethene (TCE)

Carbon tetrachloride (CT)

Chloroform (CF)

Summary and conclusions

References cited

Appendix: Sampling locations for wells and piezometers in the West Branch Canal Creek

study area, Aberdeen Proving Ground, Maryland


This report is available online in Portable Document Format (PDF). If you do not have the Adobe Acrobat PDF Reader, it is available for free download from Adobe Systems Incorporated.

 

View the full report in PDF (6.2 MB)

 

Document Accessibility:  Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.

 

For more information about USGS activities in Maryland, Delaware and the District of Columbia contact:

 

Director
MD-DE-DC Water Science Center
U.S. Geological Survey
8987 Yellow Brick Road
Baltimore, MD 21237
Telephone: (410) 238-4200
Fax: (410) 238-4210

 

or access the USGS Water Resources of Maryland, Delaware, and District of Columbia home page at:  http://md.water.usgs.gov/.


U.S. Department of the Interior, U.S. Geological Survey
Persistent URL: http://pubs.water.usgs.gov/wri024076
Page Contact Information: GS Pubs Web Contact
Last modified: Thursday, September 01 2005, 02:21:54 PM
FirstGov button  Take Pride in America button