First by way of background for everyone else: this involves a shift
from the so-called dry tomb approach to landfill designs (in which all
water is pretended to have been excluded to isolate the waste load) to one
which deliberately adds water to accelerate -- instead of supposedly
forestall -- decomposition of the organic fraction.
In my view the issue being addressed by wet cell (sometimes called
bioreactor or in-site recirculation) systems is valid. However, the means
by which the issue is addressed is questionable.
By way of further background: the fallacy of the so-called dry tomb
landfill approach that is codified in the current EPA landfill regulations
(sometimes referred to as Subtitle D) is the pretence that any barrier
system will maintain its integrity forever. Obviously, this assumption is
absurb on its face, yet that is precisely the rock upon which our so-called
"state of the art" engineering rests.
Since any barrier system will ultimately fail (and whether that means
25 years, 100 years or 250 years is irrelevant for anyone who feels it is
no more responsible to poison my great grandchildren than my kids), the key
question is whether corrective measures will be around to be undertaken at
that time when water broaches the cap and enters the waste load,
decomposition begins, leachate is generated and flows through the tears or
holes that develop in the liner, headed toward groundwater drinking water
supplies.
By attempting to maintain a dry tomb, all that we are doing is
delaying -- not preventing -- those leakages until after the time when the
landfill owner will be around to first detect and then correct these
threats to our drinking water. After all, when a $12 billion corporation
like Waste Management can see its stock value plummet from $60 to $14 in
four months and fall into technical default on its credit lines, and when
EPA regulations permit financial assurance for the liability for these
future landfill costs to both be limited to 30 years and, even within that
meaninglessly short time, to be established through captive insurance
companies whose financial strength depends upon the health of the waste
company's own stock, it seems obvious that there will be no financially
responsible party around when needed. For these reasons, cynics --
observing the relationship between the likely 30 year life of the liner and
the regulatory 30 year liability period -- have drawn the conclusion that
the purpose of the regulations was to protect the operators from liability,
not protect drinking water from contamination.
For years, engineers like Prof. Bob Ham and Dr. Fred Lee have been
attempting to force the waste industry and regulators to address this
self-apparent fallacy at the heart of our landfill regulations. In the
last three years, their exertions have finally begun to have an effect.
This is the backdrop against which the bioreactor approach has grown in
which at least some attempt is made to accelerate decomposition, and
thereby drain the waste material of its toxic loadings while the landfill
operator and the collection leachate collections systems are still around
and functioning.
The reason why I have serious reservations about bioreactors is that,
if it can be done technically in existing landfill cells (which has yet to
be adequately established), it appears only capable of partially
decomposing the organic fraction. For example, a substantial part of
discarded waste is confined in plastic bags which will isolate those loads
from the water being added, and there are questions about how effectively
water and decomposition can be dispersed through a waste load in-site.
There will be a temptation, if past history is any guide, for the
bioreactor research to be constrained so that it pursues an approach that
prioritizes a goal of developing a protocol that does not increase existing
disposal costs, and relegates to a subsidiary role the question of whether
the resulting decomposition from a least cost, in-site, recirculation
approach will protect drinking water.
I hope that you don't feel, after all this, like the little girl who
James Thurber observed writing a book report for school and noted that
"this book tells me more about penguins than I wanted to know."
Peter
____________________________________
Peter Anderson
RecycleWorlds Consulting
4513 Vernon Blvd. Ste. 15
Madison, WI 53705-4964
Phone:(608) 231-1100/Fax: (608) 233-0011
E-mail:recycle@msn.fullfeed.com