In cooperation with the U.S. Air   Force, Aeronautical Systems Center,  Environmental Management Directorate, Wright-Patterson Air Force Base, Ohio

**Subsurface Evaluation   of the West Parking Lot and Landfill 3  Areas of Air Force Plant 4, Fort Worth, Texas, Using Two-  Dimensional Direct-Current Resistivity Profiling**

By Christopher L. Braun and S.A.   Jones

U.S. Geological Survey  Water-Resources Investigations Report 02–4248

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pdf version (511 KB)

zipped plates 1–15 (3.65 MB)

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**CONTENTS**

Abstract 

Introduction 

> 
Purpose and Scope 

Description of the Study Area 

Acknowledgments 

Methods 

> 
Two-Dimensional Direct-Current Resistivity Profiling 

Data Acquisition 

Data Processing 

Subsurface Evaluation 

> 
West Parking Lot Transects 

PL–1 

PL–2 

PL–3 

PL–4, PL–5, and PL–6 

Landfill 3 Transects 

GR–1 

GR–2 

GR–3 

GR–4 

Horizontal Sections

Section 192 

Section 190 

Section 188 

Section 186 

Summary 

References 

**PLATES**

| 1–5.     | Maps showing:                                                                                               |
|---------------------|-------------------------------------------------------------------------------------------------------------|
|                | 1.                                                                                                     | Location of two-dimensional direct-current resistivity transects       in study area |
|                | 2.                                                                                                     | Water-level altitudes in the Walnut Formation, February 15, 2000, Air       Force Plant 4, Fort Worth, Texas |
|                | 3.                                                                                                     | Land-surface altitude, Air Force Plant 4, Fort Worth, Texas |
|                | 4.                                                                                                     | Terrace alluvium/fill thickness (base of terrace alluvium/fill represents       top of Walnut Formation), Air Force Plant 4, Fort Worth, Texas |
|                | 5.                                                                                                     | Depth to top of Paluxy Formation, Air Force Plant 4, Fort Worth, Texas |
| 6.             | Sections showing graphics used to interpret transect PL–4,       Air Force Plant 4, Fort Worth, Texas |
| 7–9.          | Maps showing:                                                                                               |
|                | 7.                                                                                                     | Approximate extent of dense nonaqueous-phase liquid (DNAPL) in Walnut       Formation based on IT Corporation field observations, Air Force Plant 4,       Fort Worth, Texas |
|                | 8.                                                                                                     | Altitude of top of Walnut Formation (top of Walnut Formation represents       base of terrace alluvium/fill), Air Force Plant 4, Fort Worth, Texas |
|                | 9.                                                                                                     | Altitude of top of Paluxy Formation, Air Force Plant 4, Fort Worth, Texas |
| 10–11.   | Sections showing graphics used to interpret transects:                                                      |
|                | 10.                                                                                                    | PL–1, PL–2, PL–3, PL–5, and PL–6, Air Force       Plant 4, Fort Worth, Texas |
|                | 11.                                                                                                    | GR–1, GR–2, GR–3, and GR–4, Air Force Plant 4,       Fort Worth, Texas |
| 12–15.   | Maps showing inverted resistivity values along a horizontal       section at an altitude of:                |
|                |                                                                                                        | 192 meters above sea level, Air Force Plant 4, Fort Worth, Texas |
|                |                                                                                                        | 190 meters above sea level, Air Force Plant 4, Fort Worth, Texas |
|                |                                                                                                        | 188 meters above sea level, Air Force Plant 4, Fort Worth, Texas |
|                |                                                                                                        | 186 meters above sea level, Air Force Plant 4, Fort Worth, Texas |

**FIGURES**

| 1.   | Map showing location of study area                                                                                                                                                                                                                                      |
|-----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 2.   | Diagram showing three-dimensional representation of inverted resistivity       from field data along four horizontal sections at altitudes of 192, 190,       188, and 186 meters above sea level in the west parking lot of Air Force       Plant 4, Fort Worth, Texas |

**VERTICAL DATUM**

Sea Level: In this report, “sea level” refers to the National Geodetic   Vertical Datum of 1929—a geodetic datum derived from a general adjustment   of the first-order level nets of the United States and Canada, formerly called   Sea Level Datum of 1929.

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