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Life Cycle Assessment of Brownfield ManagementP. Lesage, L. Deschênes, R. Samson
CIRAIG – Interuniversity Reference Center for the
Life Cycle Analysis, Interpretation and Management of Products, Processes and Services
NSERC Industrial Chair in Site Remediation and Management
Dept. of Chemical Engineering
École Polytechnique de Montréal
The brownfield problem
• What is a brownfield?– Site whose expansion, redevelopment, or
reuse is complicated by a real or perceived contamination (US EPA)
– Necessitates an intervention
• Widespread in industrial countries– Canada – At least 30 000 sites– USA – 130 000 to 650 000 sites
Example (case study)
• 50 ha Montreal brownfield• Heavy industrial activity 1903-1992 (railway
company’s shops)• Mixed and persistent soil and groundwater
contamination (metal, PAH, PHC, sulphur), slag
Impacts of brownfields
• Economic– Loss of economic opportunity– Devaluation of surrounding
land– Encouragement of urban
sprawl – Loss of tax base
• Environmental– IF site contaminated, human health and ecological risk– Encouragement of urban sprawl (land competition)
• Low density land occupation, car dependence, etc.
• Social– Adverse impact on
neighbourhood image– Eyesore– Higher crime rate– Worsens inner-city
deterioration
Overview of presentation
Brownfields and the urban site life cycle• Presentation of the urban site life cycle• Environmental aspects
Brownfield management• Two functions• Environmental assessment
LCA of brownfield management• Existing approaches• Single-site application• Multiple-site application
Urban site life cycle
Greenfield
Transformation
Occupation/ Exploitation
Interventionrequired ?
Occupation end
Possible legacy
• Infrastructure (maybe decrepit)– Standing– Underground
• Presence of onsite contamination– Soil– Groundwater
• Land derelict– land so damaged by development that it is
incapable of beneficial use without treatment
Sites not requiring intervention
Greenfield
Transformation
Occupation/ Exploitation
No
No action
Interventionrequired ?
Occupation end
Sites requiring intervention
Brownfields: Intervention needed for reuse
Greenfield
Transformation
Occupation/ Exploitation
Intervention
Yes Brownfield
No action
Interventionrequired ?
Occupation end
Case study – Brownfield rehabilitation and redevelopment• Intervention
– Dig & haul– Onsite containment– Cover– Material recycling
• Transformation and exploitation– Industrial park– 1250 residences– Commercial area– Green spaces
Environmental aspects
• Primary impacts:– Impacts associated with the state of the site
• Secondary impacts– Impacts associated with intervention on a
brownfield
• Tertiary impacts– Impacts on regional land use resulting from
brownfield management decisions
Primary impacts• Impacts associated with the state of the site
– Life support functions– Biodiversity– Risk (if site contaminated)
t1 t3t2
Environmentalquality (EQ)
Time
1 GreenfieldNo actionBrownfield
2 RedevelopmentInterventionBrownfield
3 GreenfieldBrownfield Intervention
Secondary impacts
• Impacts associated with intervention on a brownfield– Local impacts of intervention (noise, dust,
etc.)– Long-term fate of managed contaminants– Life cycle impacts of intervention
Tertiary impacts
• Impacts on regional land use resulting from brownfield management decisions– Reintegrating brownfields in economy
counters urban sprawl– Land transformation differential– Differential impacts of urban and periurban
land occupation
Overview of presentation
Brownfields and the urban site life cycle• Presentation of the urban site life cycle• Environmental aspects
Brownfield management• Two functions• Environmental assessment
LCA of brownfield management• Existing approaches• Single-site application• Multiple-site application
Two functions of brownfield management
• Function 1: Risk management– For contaminated brownfields– Lower human and ecosystem risk to
acceptable levels
• Function 2: Brownfield redevelopment– Prevention of urban sprawl/“Smart growth”– Socioeconomic benefits
Environmental decision support
• Primary impacts:– Many tools for risk assessment and
management
• Secondary impacts– LCA-based tools for life cycle impacts of
intervention
• Tertiary impacts– General conclusions assumed valid, often no
case-specific evaluations
No tool for treating all environmental issues under one consistent framework (except possibly MCA)
Overview of presentation
Brownfields and the urban site life cycle• Presentation of the urban site life cycle• Environmental aspects
Brownfield management• Two functions• Environmental assessment
LCA of brownfield management• Existing approaches• Single-site application• Multiple-site application
Limitations of existing LCA in the field
• Limited to risk management function– Focus on how to go about the intervention
phase– Technology comparison
• Primary impacts excluded• Long-term fate of contaminants excluded• Tertiary impacts excluded• Land use impact category not fully
exploited
Life cycle of intervention for case study
Sitecharacterisation
Site preparation
Removal ofinfrastructure
Excavation
Pumping
Backfilling
Removed drymaterial
Excavated soiland waste
management
Monitoring
Pumpedgroundwater and
contaminantmanagementBackfill
acquisition
1 ha brownfield
1 ha contaminated site
1 ha prepared contaminated site
1 ha razed contaminated site
1 ha excavated site
1 ha decontaminated site
1 ha remediated site
Energy
Materials
Water
Emissionsto water
Emissionsto air
Otherreleases
Emissionsto soil
Proposal
• LCA can provide the framework to consider:– Both functions (risk management,
redevelopment)– Whole iterations of the urban site life cycle– Three classes of impacts
• Method – system expansion
Current research project restricted to residential reuse of site
Multi-functional FU
• Two functions in functional unit:– Manage risk within constraints of policy on
contaminated site– Develop and occupy x residential units for t
years
2 options to meet functions
Option 2
Greenfield
Transformation
Occupation/ Exploitation
No
No action Intervention
Yes Brownfield
No action
Interventionrequired ?
Occupation end
Option 1
Greenfield
Transformation
Occupation/ Exploitation
No
No action Intervention
Yes Brownfield
No action
Interventionrequired ?
Occupation end
Decontamination (1ha) & redevelopment (1ha)
Restrictive measures (1ha) & greenfield development
(>1ha)
Single site application
• Decision support for what should be done with a given brownfield
• Stakeholders: Site owners, municipality and other approving bodies, lenders
“Urban sprawl”“Smart growth”Tertiary
NoneHigh impactsSecondary
No improvement
ImprovementPrimary
Option 2Option 1Impacts
LCI modeling issues• Onsite contaminants
– Brownfield considered in ecosphere– Fate model
• Long-term fate of managed contaminants– Leaching from landfills and containment cells
• Tertiary impacts– Differential land use and infrastructure from statistical data– Differential use of residences function of time
• Marginal modeling– E.g. Transportation
1
Delay
Situation
Volume/capacity
Multiple site application
• Determine impacts of applying the decision to all brownfields of Montreal
• Stakeholders: municipal and national government
• Same two options compared
LCI modeling issues
• Decontamination technology mix
• Scale of change calls for modeling scenarios– New road construction for increased
transportation– Landfill capacity a major issue
• Scaled to the same reference flow(s)
Other possible applications of framework
• Prioritizing sites for intervention
• Comparisons of different types of redevelopment (commercial, industrial)
• Evaluating impacts of contaminated site legislation
• Evaluation of the externalities of management options – correct the market failure
Conclusion
• Brownfield management is an environmentally complex issue– Primary, secondary and tertiary impacts
• LCA so far limited to secondary (and sometimes primary) impacts
• LCA can give a holistic perspective on environmental impacts of brownfield management by considering the site’s whole life cycle.