Enviromental aspects of Brownfield
Regeneration
Barbara Vojvodíková, Marcela Maturová
„This project has been funded with support from the European Commission. This publication [communication] reflects the views only
of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.“
Awareness
• What does contaminated site means?
• What are basic steps in site exploration in relation to
environmental burdens?
• What is elementary classification of decontamination
methods?
• How does selected decontamination methods work?
Goals of the teaching unit
• Explain contamination issues of brownfield sites
• Outline approaches to contamination assessment
and decontamination methods
Content
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Contaminated site term definition
Enviromental assessment procedure
Sampling steps
Decontamination methods classification
Decontamination methods examples
Contamination
Construction materials
Volatile Dust
Human health
Undeground Water
Contaminated sites
• The term 'contaminated site' refers to a well
delimited area where the presence of soil
contamination has been confirmed. The severity of
the impacts to ecosystems and human health can be
such that remediation is needed, specifically in
relation to the current or planned use of the site.
Potentially contaminated site
• The term "potentially contaminated site" includes
any site where soil contamination is suspected but
not verified and detailed investigations need to be
carried out to verify whether relevant impacts exist.
Environmental Assessment
• Traditionally brownfield environmental assessment
covers three phases:
• site assessment,
• site investigation, and
• development of remedial actions.
Site Assessment
• A preliminary examination of a site to determine the
potential contamination. It includes a review of
present and historical landuses and preliminary tests
of places that are suspected
Site Investigation
• This phase includes a more thorough review of
conditions at the site.
• Typically it includes:
• Performing soil borings and collecting soil samples;
• Installing water monitoring wells and collecting
groundwater samples from each well; and
• Analyzing all samples for the presence of
contaminants.
Environmental Sampling - 7 steps
•
The scope of environmental sampling can be
illustrated by a sample’s life with the following
seven consecutive steps:
1.
2.
3.
4.
5.
6.
7.
a sample is planned (“conceived”);
a sampling point is identified;
the sample is collected;
the sample is transferred to the laboratory;
the sample is analyzed;
the sample expires and is discarded; and
the sample reincarnates as a chemical data point
Remediation methods
• The intent of soil remediation is two-fold:
• to eliminate the exposure of humans and living
organisms to the contaminants, and
• to eliminate the sources of contamination to
groundwater.
Sorting of decontamination technologies
• by place
• according remediated media type
• used strategies
Sorting of decontamination technologies (2)
• by place
– in-situ
– ex-situ
Sorting of decontamination technologies (3)
• by type of media being remediated
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soil
sediment, sludge
groundwater
surface water
air emissions
off-gasses
Strategy
• Pollutants immobilization
• Extraction and separation from environment
• Disintegration and transformation of pollutant
• A few examples
Pic.:
Thermal desorption
• Thermal desorption removes harmful chemicals from
soil and other materials (like sludge and sediment) by
using heat to change the chemicals into gases.
• These gases are collected with special equipment.
The dust and harmful chemicals are separated from
the gases and disposed of safely. The clean soil is
returned to the site.
• Thermal desorption is not the same as incineration,
which uses heat to destroy the chemicals.
Thermal desorption
Source: http://www.epa.gov/superfund/community/pdfs/suppmaterials/treatmenttech/thermal_desorp.pdf
Air stripping
• It’s the process of forcing air through polluted water
to remove harmful chemicals.
• The air causes the chemicals to change from a liquid
to a gas (evaporate).
• The gas is then collected and cleaned.
• It’s commonly used to treat groundwater as part of a
pump and treat remedy.
Air stripping
Source: http://www.epa.gov/tio/download/citizens/airstripping.pdf
Soil washing
• Soil washing “scrubs” soil to remove and separate
the portion of the soil that is most polluted.
• This reduces the amount of soil needing further
cleanup.
• Soil washing alone may not be enough to clean
polluted soil.
• Therefore, most often it is used with other methods
that finish the cleanup.
Soil washing
Source:
Bioventing
• Technology that stimulates the natural in situ
biodegradation of any aerobically degradable
compounds in soil by providing oxygen to existing
soil microorganisms.
• Uses low air flow rates to provide only enough
oxygen to sustain microbial activity.
• Oxygen is most commonly supplied through direct
air injection into residual contamination in soil.
Bioventing
Source: http://www.frtr.gov/matrix2/section4/4_1.html
Conclusions
• For determination of site’s environmental burdens it
is necessary to perform site investigation
• Based on the findings a proper decontamination
method or combination of methods must be chosen
• There are many decontamination methods and their
suitability depends on media type and contaminants
detected
Thank you for your attention
http://browntrans.vsb.cz
„This project has been funded with support from the European Commission. This publication [communication] reflects the views only
of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.“