Click center of display for a closeup view
Subsurface Investigations
Chemical Plant
Scientists and engineers used the geological and groundwater data obtained from thousands of boreholes drilled in and around the site. In total over 26,000 linear feet of rock borings were drilled over the course of the site investigations. Thousands more feet of soil and boreholes were drilled and sampled. The vast majority of the borings were between 20 and 150 feet in depth but some select borings were drilled to a depth of 650 feet to understand the potential for deep migration of groundwater. Both the vertical and angle borings were utilized to capture the features of the earth and rock beneath the site. Surface soil samples were taken in drainage areas as well as at the chemical plant, vicinity properties, and the quarry.
Subsurface Investigation
It was through extensive geological investigations and groundwater monitoring programs that the Department of Energy and its contractors were able to determine the appropriate level of remediation. In addition, the explorations helped determine the suitability of the chemical plant site as the location for the safe construction of the long-term disposal facility.
Additional equipment not shown which was used for subsurface investigations included:
- Boutwell permeability test equipment
- Injection equipment for groundwater studies.
- Pressure transducers to collect continuous water level and water quality data.
- Push-probes to collect discrete interval soil, water, and soil-gas samples.
- Geophysical probes for locating buried debris and for underground mapping.
- Hand-held auger for soil sampling approximately 4 feet below the surface.
Tools Used in the Trade
In the field, geologists use various tools to assist in identifying and reporting what is in the earth’s subsurface. Examples shown include:
- Geologic log sheets are used to record soil or rock types which have been cored/sampled from geologic layers below the earth’s surface.
- Rock pick or hammer assists in taking rock or soil samples as well as estimating soundness or durability of the rock.
- Penetrometer readings provide general ideas on hardness or density of a rock or soil (by measuring penetration effort).
- Color charts (based on the Munsell color system) aid in identifying the rock or soil type and give geologists a standard language for documenting these materials in reports
Quarry
Subsurface investigations at the Weldon Spring Site Remedial Action Project were conducted for a number of purposes. The investigations included:
- Soil sampling to establish where the contamination was, what the levels of the contaminants were, and how deep the contaminants go.
- Defining geologic layers such as thickness of clay and depth to top of bedrock.
- Delineating contamination in the aquifer beneath the site and contaminant transport pathways.
- Determining soil properties for disposal cell construction.
- Testing technologies for use in remediation (groundwater: pump and treat, interceptor trench)
LM Navigation Bar | LM Home | DOE Website | 
