Evaluating Stormwater Management Devices—

the Role of Life Cycle Assessment

Robbie Andrew1 and Eva-Terezia Vesely2

1 NZ Centre for Ecological Economics, Palmerston North2 Landcare Research, Auckland

Summary

• Life cycle assessment (LCA)• Rain gardens• Site• Analysis• Conclusions / Future work

Today’s Purpose

Address the following:

• General perception is that rain gardens are more env friendly

• Is LCA the tool for the job?• Indirect effects and impacts are

often ignored

Life Cycle Assessment (1)

• “Cradle to Grave”• ISO 14040 series

LCA: Sounds useful…

• An objective approach• ISO 14040• Direct and Indirect impacts• Bottom-up• International data gathering effort

LCA: But…

• Assumes linearity– Production of 2kg of product impacts

environment twice as much as production of 1kg

• System boundary critical– Conclusions can strongly depend on

how much you include in the analysis

The 3 Stages of LCA

• Goal and Scope Definition• Inventory Analysis• Impact Assessment

An Application

• Goal: To compare the life-cycle environmental impact of a rain garden with that of an equivalent conventional stormwater device

Study Site

• North Shore City• Design incomplete: difficulties with

sloping terrain Cost

Raingarden: Life Cycle

Screenshot from GaBi 4

Raingarden: Production

Raingarden: Use

Raingarden: Disposal

• This is a Work in Progress• Much of initial work complete• Data collection to continue• Monitoring data to be used• Impact Assessment

Conclusions / Future Work

Acknowledgements

• Surya Pandey and Robyn Simcock of Landcare Research

• Barbara Nebel of Forest Research• Foundation for Research, Science,

and Technology