The environmental footprint of remediation covers more than just the activities at a cleanup site. The materials and energy consumed during the process may have indirect impacts on humans and the environment that may outweigh those directly associated with the site.

The life-cycle assessment (LCA) is a standardized method that can determine the impact of those activities. To date, LCA has been used primarily by businesses to benchmark operations or to evaluate and compare products or alternative processes. But there is increased interest in using it to develop consumer information to support sustainable consumption (www.epa.gov/nrmrl/lcaccess/why-lca.html).

When applied to remediation, LCA focuses primarily on onsite resource and energy consumption, as well as environmental impacts that occur off the contaminated property, such as transportation and fuel production, and the regional health effects of emissions. A life-cycle assessment can provide benchmarks for existing systems and retrospectively identify opportunities to decrease impacts in future cleanups. It can also be used to compare different remediation options when selecting technology.

Life-cycle framework as applied to remediation The application of life-cycle management to remediation should include cradle to grave considerations as well as the local, regional and global impacts of all activities. This should include raw materials acquisition, use and ultimate disposal as life-cycle phases, and account for outputs such as emissions and their impact to human and ecosystem health.

The broad spectrum of impact categories provided by LCAs can be incorporated into a full cost-benefit analysis that includes external factors not traditionally considered. Tools are available for total cost accounting as well (www.earthshift.com/tools.htm). With life-cycle management, we can expand short-term and narrow economic decision making to include the full environmental and human health impacts.

But conducting a full assessment can prove time intensive and costly. The best option is often difficult to choose because of consequential environmental trade-offs. The LCA approach is a systematic and rigorous assessment that categorizes the results into 12 to 20 separate ecosystem and human impact categories. Table 1 on the following page shows just a few of these as they relate to specific stressors.

Boiling down a dozen or more impact category results to a single score for easy interpretation is helpful. However, trying to weigh the relative importance of diverse impacts such as global warming, human health and acidification can be controversial.

There are, however, some acceptable ways by which to group the results into several umbrella categories, such as resource consumption and human and ecosystem impacts.

Only a few studies have been conducted to evaluate the use of LCA for remediation. Most follow two life-cycle frameworks developed specifically for remediation: one for the Ontario Ministry of the Environment (ISBN 0-7778-6940-3) and another for NATO (EPA 542-R-01-002).

The Canadian framework includes a matrix system for evaluation using life-cycle management criteria. This can be used as a screening tool to reveal broader impacts in lieu of a full assessment. After forming a process flow diagram and identifying all the inputs and outputs for each process, individual inventory items are linked with a potential environmental impacts checklist that associates the impacts with the physical, chemical or biological stressors. Each stressor can be ranked by level of concern if enough process information is known.

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At its most basic level, the framework approach helps to identify key areas for improvement or opportunities for reducing burdens.

Currently, there are no standardized tools to tell us how far we must reach to reduce the burdens that would take us to a happy medium of sustainability. At a minimum, applying life-cycle thinking, expanding the site boundary beyond the fence line and considering green alternatives would be great progress. We need to apply broader and more complete thinking to better inform the public, policy makers, property owners, and technology vendors so that decisions minimize the overall burdens and costs to society. In effect, life-cycle thinking tells us in which direction to go to reduce burdens and a life-cycle assessment can help quantify the improvements made.

Bob Boughton is a senior engineer at the California Department of Toxic Substances Control. Any views expressed in this article are the views of the author’s and do not necessarily represent the views of the Calif. EPA.