(Bank et al. 2002). Thus, it is recommended to apply noise barriers together with
wildlife passages to promote crossings between railway sides in order to maintain
dispersal processes and ensure the long-term persistence of the species (Bank et al.
2002; Schulte-Werning et al. 2012). However, reducing the noise disturbance may
reduce the ability of wildlife to perceive incoming trains, and consequently increase
the risk of collision (see Chap. 2).
Soil Pollution
Cleaning the ballast using ethylenediaminetetraacetate (EDTA) with water or
thermosetting plastic resin are techniques that allow the recycling of pollutant
components in the surroundings of the railway network. Cleaning it can typically
involve the use of products such as solvents or surfactants, which vary in efficiency
and potential environmental impacts (Anderson et al. 2002). The ballast cleaning
technology with aqueous solutions of disodium EDTA can ensure metal extraction
without altering the stones’ mechanical and physical characteristics, allowing reuse
of the ballast (Di Palma and Petrucci 2015). The use of EDTA offers a high
extraction efficiency of heavy metals (Di Palma et al. 2011); however, this chemical
agent should be administered with caution because it has low biodegradability in
the environment (Bucheli-Witschel and Egli 2001).
Using water to extract the ballast pollutants is very common in many countries
(Di Palma et al. 2012). However, this method requires a great amount of surfactant
water, and the disposal of the waste produced after cleaning must be treated
appropriately (Cho et al. 2008). Incineration, landfilling, or recycling of the waste
are the options available, with the choice depending on the solvent system and on
the nature of the waste (Anderson et al. 2002). Dry cleaning that uses thermosetting
plastic resin can successfully remove ballast pollutants in a very short time (Cho
et al. 2008). In areas with high levels of contamination, the support material should
be renovated regularly, including changing the ballast, and wood sleepers should be
replaced by concrete (Wiłkomirski et al. 2011).
Soil Erosion
There are techniques commonly used to minimize the effects of soil erosion on
railways and highways: grass plantation, use of gypsum, application of
compost/mulch coverage, use of concrete prefabricated panes, lattice plots, and
interception and drainage. There is evidence that as the grass cover level increases,
the soil erosion rate decreases (Gyasi-Agyei et al. 2001). For example, buffel grass
(Cenchrus ciliaris) is one of the preferred species for revegetation of railway
embankments in Australia (Bhattarai et al. 2008); in some of the areas (Central
Australia and Western Queensland), this grass spreads readily in soils with crumbly
6 Railway Disturbances on Wildlife: Types, Effects, and Mitigation …
91
wildlife passages to promote crossings between railway sides in order to maintain
dispersal processes and ensure the long-term persistence of the species (Bank et al.
2002; Schulte-Werning et al. 2012). However, reducing the noise disturbance may
reduce the ability of wildlife to perceive incoming trains, and consequently increase
the risk of collision (see Chap. 2).
Soil Pollution
Cleaning the ballast using ethylenediaminetetraacetate (EDTA) with water or
thermosetting plastic resin are techniques that allow the recycling of pollutant
components in the surroundings of the railway network. Cleaning it can typically
involve the use of products such as solvents or surfactants, which vary in efficiency
and potential environmental impacts (Anderson et al. 2002). The ballast cleaning
technology with aqueous solutions of disodium EDTA can ensure metal extraction
without altering the stones’ mechanical and physical characteristics, allowing reuse
of the ballast (Di Palma and Petrucci 2015). The use of EDTA offers a high
extraction efficiency of heavy metals (Di Palma et al. 2011); however, this chemical
agent should be administered with caution because it has low biodegradability in
the environment (Bucheli-Witschel and Egli 2001).
Using water to extract the ballast pollutants is very common in many countries
(Di Palma et al. 2012). However, this method requires a great amount of surfactant
water, and the disposal of the waste produced after cleaning must be treated
appropriately (Cho et al. 2008). Incineration, landfilling, or recycling of the waste
are the options available, with the choice depending on the solvent system and on
the nature of the waste (Anderson et al. 2002). Dry cleaning that uses thermosetting
plastic resin can successfully remove ballast pollutants in a very short time (Cho
et al. 2008). In areas with high levels of contamination, the support material should
be renovated regularly, including changing the ballast, and wood sleepers should be
replaced by concrete (Wiłkomirski et al. 2011).
Soil Erosion
There are techniques commonly used to minimize the effects of soil erosion on
railways and highways: grass plantation, use of gypsum, application of
compost/mulch coverage, use of concrete prefabricated panes, lattice plots, and
interception and drainage. There is evidence that as the grass cover level increases,
the soil erosion rate decreases (Gyasi-Agyei et al. 2001). For example, buffel grass
(Cenchrus ciliaris) is one of the preferred species for revegetation of railway
embankments in Australia (Bhattarai et al. 2008); in some of the areas (Central
Australia and Western Queensland), this grass spreads readily in soils with crumbly
6 Railway Disturbances on Wildlife: Types, Effects, and Mitigation …
91