Soil
Soil samples of the material
that must be excavated to reach valuable ore bodies (overburden)
are taken before, during, and after mining and reclamation has taken
place. Soil samples are taken prior to the initiation of mining
activities in order to characterize important soil parameters indicative
of soil health (i.e. nutrient availability, soil structure, organic
matter content, pH). This information is collected to establish
pre-mining conditions which will be used to optimize reclamation
efforts. For abandoned mines, pre-mining information is commonly
not available. In these cases, native soil parameters are commonly
assessed at nearby sites. Soil samples are also taken after reclamation
activities have been completed to ensure that soil health has been
regained and to ensure that all soil contamination is either removed,
contained, or treated. Samples may also be taken of excavated, stockpiled
soils to determine whether important soil parameters have been depleted
from the soil matrix, especially if the soils are to be used as
topsoil for reclamation purposes. In addition stockpiled soils may
be intermixed with waste material which can cause soil contamination.
As a result, soil samples should also be analyzed to determine if
they are acidic or metal laden.
Soil samples are obtained by similar methods as tailings and waste
rock. Unlike waste rock, soil samples can be collected fairly easily
using drilling methods. The soil particles are smaller and are more
easily recovered on auger flights or as core samples. Obtaining
representative samples is still a challenge since, by nature, soils
type varies greatly both vertically and horizontally. It is important
to establish a well-planned sampling program that ensures representativeness
of the area. For more information on creating representative sampling
programs, see the data quality
section. Different drilling techniques are necessary depending
on whether the goal of the investigation is to collect undisturbed
samples or if disturbed samples will be sufficient. Samples are
classified as undisturbed or disturbed depending on how much alteration
there is to the soil
structure after it is removed from its in-situ state. The type
of drilling technique used also depends on whether only collection
of soil samples is desired or if the installation of a monitoring
well is also desired. When drilling for the purposes of installing
a monitoring well, a hollow stem technique should be used since
they create an opening for the monitoring well to be placed. Soil
samples are taken from cores that remove soil inside the hollow
stem. For more information on the different drilling methods, see
the tailings section.
Problem | Compliance
| Health & Safety | Sampling
| Analytical | Data
Quality
Site Assessment | Prediction
| Construction | GIS
| Monitoring & Assessment
|
