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.“

Contents

• Contaminated site term definition• Enviromental brownfield assessment procedure• Sampling steps• Decontamination methods classification• Decontamination methods examples

Contamination

Human health

Undeground WaterVolatile DustConstruction materials

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 Brownfield 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.

Remediation methods

• The intent of 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 in-situ ex-situ

according remediated media type

soilsediment, sludgegroundwatersurface waterair emissionsoff-gasses

used strategies Pollutants immobilization

Extraction and separation from environment

Disintegration and transformation of pollutant

Ruhr District, Germany, 2011

Example of contaminated soil isolating

Photo by B. Vojvodíková

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.

Source: http://www.epa.gov/superfund/community/pdfs/suppmaterials/treatmenttech/thermal_desorp.pdf

Thermal desorption

Air stripping

• It is 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 is 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: http://www.epa.gov/superfund/community/pdfs/suppmaterials/treatmenttech/soil_washing.pdf

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.

Source: http://www.frtr.gov/matrix2/section4/4_1.html

Bioventing

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.“