Use of Borehole Geophysical Logging to Determine Fracture Distribution, Orientation, and Flow Directions and Rates in New Boreholes at the Ordnance Product Site, Cecil County, Maryland
WRD PROJECT #: MD187
PROJECT CHIEF: Phelan, Daniel J.
BEGIN DATE: 01-July-1998
END DATE: 30-Sept-2001
Customers currently supporting the project:
U.S. Environmental Protection Agency
Problem
Various munitions products, including fuses and detonators for military products, were assembled from 1960 to 1973 at the Ordnance Products site in Cecil County, Maryland. It is now a Superfund site that is administered by U.S. Environmental Protection Agency (USEPA) Region III. The primary problem is contamination of soil, surface water, and ground water with volatile organic compounds. USEPA will drill five new bedrock boreholes during FY99 and has requested USGS assistance with geophysical logging of these and three previously drilled boreholes, to identify and gain a better understanding of possible contaminant migration pathways through fractures in the bedrock.
Objectives
Determine fracture distribution, orientation, and flow directions and rates in at least eight boreholes at the Ordnance Products site.
Approach
The following geophysical logs will be run in at least five boreholes in the order listed, if scheduling of the equipment permits:
- Borehole video camera;
- Natural gamma;
- Single point resistance;
- Fluid temperature and resistivity;
- Caliper;
- Digital acoustic televiewer;
- Heat-pulse flowmeter.
Geophysical logging was performed August through September, 1999. Water-level measurements were made in each borehole at the start of the logging operations.
A Health and Safety Plan (HASP) approved by USGS was provided to USEPA before the start of operations. The borehole geophysical logs will be presented and interpreted in an Administrative Letter report to USEPA. The fist draft of the report was submitted to the USEPA in October, and is currently in review.
