Sustainable Geoenvironmental Engineering Practice - Sustainable Practices in Geoenvironmental Engineering - page 474

The ordinate shown in the diagram represents soil quality index (SQI). The SQI
is a composite index that incorporates analyses that include consideration of the
physical, chemical, and biological indicators relating to the soil resource applica-
tion under review. Thus, for example, the speciic component indicators for the
physical, chemical, and biological indicators leading to calculations of the SQI for
waste management would differ from those obtained for agricultural production,
or for forestry. A more detailed discussion of the SQI and the various indicators
will be found later in this chapter.
Artiicial recharge—i.e., recharge through human intervention—involves the use of soil
conditions, fertilizers, added nutrients, biological agents, and good agricultural land man-
agement practice. The term soil amendments is used as a general catch-all term to include
all the preceding items and processes. These soil amendments, when introduced into a
tired soil, are designed to improve the soil qualities through improvement of the physi-
cal, chemical, and biological properties of the soil—to allow for better use of the soil as a
resource material. Improvements in soil permeability, iniltration, water retention, nutrient-
holding capacity, and soil structure—on top of the addition of nutrients and fertilizers—
constitute the artiicial soil recharge process.
13.3.2.3 Protection of Soil and Water Resources
The impacts of signiicant consequence on the soil and water resources in the geoenviron-
ment are due to physical disturbances of the land environment and direct and/or con-
tamination of the soil and water resources, as shown in Figure 13.1. The various factors,
conditions, and circumstances wherein impacts are generated have been discussed in
the previous chapters. The three different categories for protection of the soil and water
resources in the land environment are
1. Direct and speciic protective measures to ensure no degradation of soil and water
qualities. This category of actions and measures assumes that the soil and water
qualities are at acceptable levels, and that with proper management, they will be
sustainable.
2. Measures and actions to mitigate and minimize detrimental impact to both soil
and water qualities. We assume that the impacts are managed to the extent that
their effects do not degrade both soil and water qualities and also do not pose
health threats to humans and other biotic receptors.
3. Application of treatment and remediation technologies to return soil and water
qualities to levels acceptable for use. This category applies to situations where
soil quality and/or water quality have degraded to the state that treatment and
remediation are required to return them to the levels of quality required for
use.
The actions included in the various measures undertaken for the three categories of pro-
tection and management of soil and water resources range from passive to aggressive. The
physical and chemical buffering properties of the soil are central to the effectiveness of the
passive protection technique. At the other end of the scale are physical protection barriers
such as liner-barrier systems that prevent the migration of leachates and contaminants
and treatment, and remediation techniques that require aggressive physical, chemical, and