B.

One of two methods will normally be used to explore the subsurface. Either the area will be
ditched with a backhoe so that trenches can be entered for sidewall samples, or it will be
probed with a core-type earth auger according to an area and depth design pattern.

Each

method has advantages that depend on the situation. The auger is less physically disturbing to
the area, but if metal or other buried objects are discovered, a backhoe or other substitute
method may have to be employed,
C.

Subsurface soil samples will be identified with their grid location and depth measured in
centimeters from the surface of the ground to the top of the soil removal point. The nominal

sample size will be about 500 em3,

VI.

D.

Sidewall samples from a trench or core samples from an auger will be analyzed in a fixed
calibrated geometry using an intrinsic Ge detector and multichannel analyzer.

E.

It is emphasized that subsurface sampling is exploratory and may require a change in direction
during an operation. The important ingredients are planning, flexibility, and experienced
supervision. Under certain conditions, the FIDLER or PG-2 detectors may be used effectively
to facilitate searches for contaminatedsoil areas.

Soil Sampling Area Selection

A soil sample (for in situ van calibration purposes) shall be taken in each 4-hectare parcel. For a 24-hectare
island, this would call for 6 sample locations. Islands smaller than 16-hectare will still require 4 areas to be

sampled. For example:

24-Hectare Island

A-4-3

Select target paragraph3