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

Anaya, Roberto; Braun, Christopher L.; Kuniansky, Eve L.

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.

Genre:

USGS Numbered Series

ProdID:

25907

Citation Author:

Anaya, Roberto; Braun, Christopher L.; Kuniansky, Eve L.

Citation Contributing Office:

Geological Survey (U.S.)

Citation Datum:

Citation Day:

Citation Edition:

Citation Editor:

Citation End Page:

Citation Issue:

Citation Keywords:

Citation Language:

ENGLISH

Citation Larger Work Title:

Citation LatN:

0324500

Citation LatS:

0324300

Citation LonE:

-0965800

Citation LonW:

-0970000

Citation Month:

Citation No Pagination:

Citation Number Of Pages:

Citation Online Only Flag:

Citation Phsyical Description:

Report: iv, 10 p.; 3 Plates

Citation Projection:

Citation Public Comments:

Prepared in cooperation with the Southern Division Naval Facilities Engineering Command

Citation Publisher:

Geological Survey (U.S.)

Citation Series:

Water-Resources Investigations Report

Citation Series Code:

WRI

Citation Series Number:

2000-4150

Citation Search Results Text:

Use of Borehole Geophysical Logs for Improved Site Characterization at Naval Weapons Industrial Reserve Plant, Dallas, Texas; 2000; WRI; 2000-4150; Anaya, Roberto; Braun, Christopher L.; Kuniansky, Eve L.