Environmental Engineering Reference
In-Depth Information
contaminants—thought it was a “usual'' soil and groundwater contamination with the
contaminant mixture floating on the surface of the groundwater overlain and under-
lain by a naturally occurring waterproof clay layer. However, painful and expensive
experience revealed the extreme behavior of chlorinated hydrocarbons that was able
to seep through the waterproof clay layer and reach the deep subsurface waters, Hun-
gary's carefully protected drinking water reservoir. Another unpleasant surprise was
that the incineration of such an uncontrolled mixture of chemicals needed special pre-
paredness and equipment, so that only a small part was burned in Hungary, and about
14,000 tonnes of hazardous waste had to be transported to and destroyed in Austria
and Germany in special incinerators. As much as 150,000 tonnes of contaminated soil
remained at the waste disposal site still endangering groundwater, drinking water and
humans. Eventually, the owner declared bankruptcy without a successor in 2007.
Similar situations can still be identified in Europe and in many developing coun-
tries; that is why the lesson learned from the historical contamination cases is important
to disseminate. The cases draw the attention to risk communication, which should be
an important tool in risk management. The risk communication of the industrial and
mining companies has been insufficient in many European countries; the Hungarian
red mud flood case clearly demonstrates this: people of Kolontár and Devecser, West-
ern Hungary (two settlements downstream from the Ajka red mud pond) did not know
anything about red mud and its alkalinity in spite of living only a few meters away
from the red mud pond number ten, which failed in 2010.
3 TYPICAL SOIL CONTAMINANTS
Typical soil contaminants can be emitted onto soil through the atmosphere in the form
of wet and dry deposition by precipitation (in dissolved form) or wind (particulate
matter), through surface waters by floods and by solid erosion.
Typical soil contaminants polluting soil via atmosphere may be the following:
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PAHs from heating and incineration;
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Polychlorinated biphenyl and dioxins from incineration;
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Metals from smelters;
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Metals from traffic (fuel combustion: lead, cadmium, copper, antimony);
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Acid rain;
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Particulate matter.
Soil contamination with the mediation of surface waters may be the following:
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Contaminated run-off water;
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Eroded contaminated solid material or waste;
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Floods disposing of contaminated sediment on soil.
Direct contaminant input into and onto soil may be the following:
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Industrial sites and areas where chemicals are produced and used;
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Subsurface pipes and containers for petroleum hydrocarbons, storage and trans-
port of fuel and liquid chemicals;
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