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[greenyes] Life Cycle Cost Analyses as Junk Science

    When our usually discerning environmental economics reporter John Reindl
reports "For those interested in the concept of life cycle assessments as
applied to solid waste issues, you may be interested in a Finnish document
published last year with the title:  "Guidelines for the use of LCA in the
waste management sector", and available as a PDF document at
http://www.nordtest.org/register/techn/tlibrary/tec517/tec517.pdf,"; he
appears to have hotchskipped over some of that discernment.

    I read the study, and it is not good at documenting its inputs, and much
of it is little more than standard landfill apologia, without any factual
basis for any of its many controversial statements that minimize landfills'
environmental impacts.

    For example, it repeats the claims that bioreactors have
enhanced gas collection systems.  This is a key issue because concerns over
climate change would preclude any new system that introduces major new
volumes of greenhouse gases.

    To be clear, there has been NO published factual basis for such claims,
other than constant unsupported repetition of the naked assertion; and
indeed, the truth is precisely the opposite.

    For one thing, the standard rigid vertical pipes that have been found to
have the maximum drawing power to extract gas are generally not feasible in
bioreactors because the rapid differential decomposition tilts and breaks
them.  Instead flexible horizontal piping is often used which cannot support
as high negative pressures and tend to dip in soft spots and then flood,
which reduces
efficiency further.

    Moreover, whether vertical or horizontal, no gas collection system can
work effectively before the cap is installed over the closed landfill cell
creating a seal on top.  This is because, with the pipes spaced far apart,
the same vacuum that extends around the piping to reach far enough to draw
the gas from within the surrounding waste mass to the next pipe's zone of
influence will also extend to the surface and draw oxygen from the unsealed
surface. When oxygen mixes with
methane in the landfill, explosions and fires tend to occur, which is not
good.  Consequently, when air shows up in the gases in the piping more than
3-5%, the operators have to throttle the system and the efficiency degrades
unacceptably.

    This is important because bioreactors are operated to recapture air
space and that implies postponing the cap for years, all the time the rapid
decomposition fostered in these landfills concentrates most of the gas
creation into those very years when the collection system is throttled.

    So far, the bioreactor operators seem to have bamboozled the regulators
by pointing to higher gas capture volumes in the early years than in dry
tomb landfills.  But that completely misses the point. If gas creation has
increased ten times, for example, and gas capture has only doubled, one can
get a clearer picture of the potential magnitude of the problem.

    Europe is a source of much forward looking waste analyses and policies.
This, unfortunately -- with apologies of those on the list with Finnish
antecedents -- is not one of them.


                                                        Peter




______________________________
Peter Anderson
RECYCLEWORLDS CONSULTING Corp
4513 Vernon Blvd. Suite 15
Madison, WI 53705
Ph:    (608) 231-1100
Fax:   (608) 233-0011
Cell    (608) 438-9062
email: anderson@no.address







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