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The environmental survey made according to the
assignment given by MÁVÉPSZER at a MÁV (Hungarian State Railways) railway
station revealed a hydrocarbon contamination in the soil and the groundwater.
The estimated volume of the contaminated soil in an area of
8200 m2 was about 24 020 m3 with an affected groundwater body of a similar size.
8200 m2 was about 24 020 m3 with an affected groundwater body of a similar size.
The contamination was caused by diesel leakage
from oil skimmer tanks and storage tanks in the northern parts, diesel leakage from
a refueling unit in the southern part, and several other oily cooling liquid
and machine oil leakage also in the southern part of the station.
While planning the intervention, it was an
important issue that the intervention should not or only slightly interfere in
the running of the railway station.
Water treatment was carried out with
pump-and-treat technology, using air-stripping towers and skimmer equipment. In
case of soil treatment we used an enzymatic ex situ method (using depots and
watering) on the shallowest soils and in situ method (drain-ditches,
air-sparging injection wells) for soils deeper than 80-100 cm.
During the operation about 100 000 m3
water was yielded and treated and more than
5000 liters of free phase floating hydrocarbon was skimmed. Additionally the soils were treated as well. Ultimately the contamination in the station was completely eliminated, which was confirmed by the follow-up monitoring test as well.
5000 liters of free phase floating hydrocarbon was skimmed. Additionally the soils were treated as well. Ultimately the contamination in the station was completely eliminated, which was confirmed by the follow-up monitoring test as well.