In cooperation with the Southern   Division Naval Facilities Engineering Command

**Use of Borehole   Geophysical Logs for Improved Site Characterization at Naval Weapons Industrial   Reserve Plant, Dallas, Texas**

By Roberto Anaya, Christopher L.   Braun, and Eve L. Kuniansky

U.S. Geological Survey  Water-Resources Investigations Report 00–4150

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pdf (533 KB)

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**CONTENTS**

Abstract 

Introduction 

Purpose and Scope 

Description of Study Area 

Approach 

Use of Borehole Geophysical Logs 

Gamma-Ray Log Processing and Analysis 

Cone-Penetrometer Test Log Processing and Analysis 

Electromagnetic-Induction Log Processing and Analysis 

Site Characterization 

Summary 

References 

**PLATES**

1�3. Maps showing: 

> 
1. Lines of section and logged well locations, Naval Weapons Industrial Reserve     Plant, Dallas, Texas     (pdf 26" X 20.5", 348 KB)

2. Lithologic sections *A�A'*, *C�C'*, *D�D'*, and *F�F'*     at Naval Weapons Industrial Reserve Plant, Dallas, Texas     (pdf 24" X 20", 534 KB)

3. Lithologic sections *G�G'*, *L�L'*, *M�M'*, *P�P'*,     *Q�Q'*, and *R�R'* at Naval Weapons Industrial Reserve Plant, Dallas,     Texas     (pdf 36" X 20", 661 KB)

**FIGURES**

1. Map showing location of the study area 

2. Graph showing comparison of natural, filtered, and classified gamma-ray   log data 

3. Graph showing comparison of a cone-penetrometer test (CPT) log and a nearby   gamma-ray log 

4. Boxplots showing range and distribution of conductivity for wells with no   detected contaminants 

**TABLE**

1. Statistics for clay-content sediment classes in uncontaminated areas of   the shallow alluvial aquifer 

**VERTICAL DATUM, ABBREVIATIONS,   AND ACRONYMS**

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

**Abbreviations:**

cm/s, centimeter per second 

cps, counts per second 

°F, degree Fahrenheit 

ft, foot 

ft/s, foot per second 

gal/d, gallon per day 

gal/min, gallon per minute 

in., inch 

µg/L, microgram per liter 

mi, mile 

mS/m, millisiemens per meter 

**Acronyms:**

CPT, cone-penetrometer test 

EM, electromagnetic 

GOCO, government-owned, contractor-operated 

NAS, Naval Air Station 

NWIRP, Naval Weapons Industrial Reserve Plant 

RCRA, Resource Conservation and Recovery Act 

RFI, RCRA Facility Investigation 

SOUTHDIV, Southern Division Naval Facilities Engineering Command 

TCE, trichloroethene 

USGS, U.S. Geological Survey

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**Abstract**

A shallow alluvial aquifer at the Naval Weapons Industrial Reserve Plant near   Dallas, Texas, has been contaminated by organic solvents used in the fabrication   and assembly of aircraft and aircraft parts. Natural gamma-ray and electromagnetic-induction   log data collected during 1997 from 162 wells were integrated with existing   lithologic and cone-penetrometer test log data to improve characterization of   the subsurface alluvium at the site. The alluvium, consisting of mostly fine-grained,   low-permeability sediments, was classified into low, intermediate, and high   clay-content sediments on the basis of the gamma-ray logs. Low clay-content   sediments were interpreted as being relatively permeable, whereas high clay-content   sediments were interpreted as being relatively impermeable. Gamma-ray logs,   cone-penetrometer test logs, and electromagnetic-induction logs were used to   develop a series of intersecting sections to delineate the spatial distribution   of low, intermediate, and high clay-content sediments and to delineate zones   of potentially contaminated sediments. 

The sections indicate three major sedimentary units in the shallow alluvial   aquifer at NWIRP. The lower unit consists of relatively permeable, low clay-content   sediments and is absent over the southeastern and northwestern part of the site.   Permeable zones in the complex, discontinuous middle unit are present mostly   in the western part of the site. In the eastern and southeastern part of the   site, the upper unit has been eroded away and replaced by fill material. Zones   of potentially contaminated sediments are generally within the uppermost clay   layer or fill material. In addition, the zones tend to be local occurrences.

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