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.