SWANA's upcoming conference in March is on landfill gas, not bioreactors. I suppose they will cover bioreactors as a subspecies of landfills producing gas for energy or whatever, though. Sorry for the "misremembering."
Urban Ore, Inc.
On Feb 15, 2008, at 3:27 PM, Dan Knapp wrote:
I too remember some discussion on leachade recirculation, and maybe the current "bioreactor" technologies could count recirculation as an ancestral practice, but I believe they are a different animal with different capital requirements and different motives. SWANA is doing a whole conference this year on bioreactors; anyone going? We ought to be sending people to these things to find out what they're proposing and bring back more current info.
Urban Ore, Inc.
On Feb 14, 2008, at 10:01 AM, amy perlmutter wrote:
Just a point on your point below that ?when a generally-accepted principle is upended in favor of its opposite, as when "dry tomb" landfilling as best landfill practice suddenly changes to "saturate it with water" landfilling, the public has every right to smell a rat.?
When I first started getting involved in solid waste in the very early 80?s, my recollection is that what is now called a bioreatctor was state of the art in landfilling. I haven?t kept up with all the discussion on this so may be wrong as to exact definitions, but I do know that what was being touted as best landfill design back then was recirculating the leachade (much better term than leachate!). That was a long time ago, but my memory is that it was supposed to speed up decomposition and may have had some other benefits as well, such as toxicity reduction of the leachade. I?m not making a statement for or against that type of design, just saying that perhaps bio-reactor landfills were upended for dry tomb.
23 Avon Street
Cambridge, MA 02138
On 2/14/08 3:35 AM, "GreenYes group" <email@example.com> wrote:
> == 1 of 2 ==
> Date: Wed, Feb 13 2008 1:28 pm
> From: Dan Knapp
> Hello there,
> On Alan's point about leachate degradation of rubber/plastic liners,
> some years back I helped Lane County, Oregon avoid a costly mistake
> when they discovered that their hillside landfill between Eugene and
> Cottage Grove had sprung multiple leaks that were draining leachade
> into the Willamette River via Camas Swale, a wetland located at the
> foot of the landfill. The county solid waste people wanted to build
> a seven-mile plastic pipeline to take the collected leachade to the
> municipal sewage treatment plant in Eugene, a public works project
> that would have cost many millions and that would have created
> pressure for urban sprawl on both sides of the new sewer main. The
> argument that won the day for onsite treatment (still only a
> palliative, but better than the pipeline) was strong research
> evidence I summarized in an Op-ed piece for the Eugene Register-Guard
> that common solvents such as trichlorethelyene easily migrate through
> plastic barriers, even rigid plastic ones, and that over time,
> continued migration accelerates erosion, decomposition, and failure
> of the plastic barriers. So yes, I believe Alan is right that adding
> water (a powerful solvent) to all the other known and unknown
> solvents present in mixed-waste landfills will increase hydrostatic
> pressure, greatly increase mass that wants to flow downhill in
> response to gravity, and accelerate degradation of rubber/plastic
> In general when a generally-accepted principle is upended in favor of
> its opposite, as when "dry tomb" landfilling as best landfill
> practice suddenly changes to "saturate it with water" landfilling,
> the public has every right to smell a rat.
> As I said in an earlier post, my hypothesis as to why waste companies
> are so strong for bioreactorism right now is that it would ultimately
> shrink the volume of the landfill contents, so that the companies
> might apply for extending permitted airspace on top of the old cells
> and keep their heavily subsidized mix/mash/bury profit machine going
> a few years longer. Maybe I'm wrong about this, but it seems
> plausible given the difficulty landfill fans now have convincing
> others to go along with their preferences and grant them new
> permitted airspace above whatever new virgin wetland or headwaters
> area they pick next. Also it allows them to do more greenwashing by
> claiming to generate energy from stuff no one wants, which they
> manufacture with their collection methods.
> Yours for source separation and an end to phony "recycling"
> technologies of all stripes and types.
> Dan Knapp
> Urban Ore, Inc.