Page 263 - Materials Chemistry, Second Edition

LIFE CYCLE ASSESSMENT AND END OF LIFE 251

perspective encourages waste planners to consider the environmental aspects
of the entire system including activities that occur outside of the traditional
framework of activities from the point of waste collection to final disposal, as
well as outside of cities and regions where wastes are generated. Since many
cities and regions transport their waste out of their community or state for man-
agement and disposal, the impacts of managing waste generated are not often
captured. LCA helps bring the "out-of-sight, out-of-mind" into sight and mind.
Waste management is a challenging issue because it must balance the techno-
logical, economic, environmental, and social dimensions. All of these play key
roles in the decision making process for waste management. Understanding
these multi-dimensional relationships is necessary for reaching sustainable
solutions. LCA provides a key piece to understanding the broad environmen-
tal aspects of waste management and must be combined with technological,
economic, and social information to make effective decisions. An LCA of waste
management can serve as either to support the development of a product LCA,
or to investigate and evaluate waste management alternatives and strategies
for decision making such as the U.S. Environmental Protection Agency's solid
waste management hierarchy (US EPA, 2012).
Most communities know the cost and [to varying extents] local emissions
associated with their waste management facilities, but few can capture the
comprehensive picture of the true burdens and benefits that occur outside of
their immediate region and infrastructure. LCA not only expands the bound-
aries to consider a broader scope of environmental burdens but, and perhaps
more importantly, captures benefits of materials and energy conservation
and recovery. Table 11.1 provides a qualitative overview of the key life cycle
burdens and benefits associated with waste management alternatives.
For example, material recycling means less waste to be disposed of in a land-
fill but also requires infrastructure and equipment for collection, processing
and transportation. On the benefits side, material (paper, plastic, metal, glass)
recycling avoids landfill-related impacts and creates beneficial offsets by virtue
of displacing the use of virgin resources. Figure 11.1 illustrates the calculation
of this beneficial offset for newsprint. The magnitude of the beneficial offset
varies considerably by material. For example, metals recycling exhibits large
offsets whereas glass has relatively smaller offsets (on a tonnage basis).
Energy recovered from waste via waste-to-energy (WTE) and/or landfill
gas-to-energy also creates beneficial offsets by virtue of displacing the use of
fossil (and other) fuels to produce electrical energy in the utility sector. The
magnitude for offsets varies by regional electricity grid mix and whether base
load or average load is assumed to be displaced.

11.3 LCA of Waste Management Versus GHG Inventory/
Reporting, Sustainability Reporting, and Other
Environmental Initiatives

In general, an LCA takes a comprehensive global perspective regardless of
where a particular operation is located or who has "ownership" of emissions.