Re: [GreenYes] landfill calculations

["Roger Guttentag" <rgutten@concentric.net>]

Dear Wayne:

The following are comments based on a very quick review of your attached
spreadsheet.

The problematic parts of your analysis I think revolves around your
assumptions regarding:

1. The in-ground compaction density in your landfill.

Your analysis is based on an "in-truck" density of about 750 lbs / cy for
MSW.  The actual in-ground landfill compaction density should be much higher
(see link to the following article -
http://www.forester.net/mw_0109_operations.html )

2. The impact on landfill in-ground compaction densities by removing OCC.

The other issue not examined by your analysis would be any possible
beneficial improvements in landfill compaction densities by the removal of a
light density material like OCC.  This, in turn, would positively impact
working landfill life.

A brief comment on your spreadsheet style:

It shows the typical ad-hoc structure that results from "thinking into the
worksheet".  Even though it is short it is not easy to follow.  I would
suggest the following structure for your worksheet:

I. Results section - include a brief explanation as to what you are trying
to show.
II. Assumptions section - all working assumptions and calculation constants.
III.  Analysis section - Show sequence of calculations leading to result
seen in first section.

Appropriate use of borders to demarcate sections, brief descriptive labels
for specific calculations and selective use of gray shading to highlight
important numbers would be helpful as well.

Roger M. Guttentag
610-584-8836
rgutten@concentric.net

----- Original Message -----
From: Wayne Turner <WAYNET@cityofws.org>
To: <greenyes@grrn.org>
Sent: Monday, December 03, 2001 9:53 AM
Subject: [GreenYes] landfill calculations


I've attached an excel spreadsheet with calculations for expected landfill
savings from an OCC ban that we're trying to implement.  I'd appreciate any
feedback on the assumptions and calcuations that I've made.  I'm not aware
of any universal LF savings calculation model so I've sort of made it up as
I go.  Critique/suggestions sought and appreciated.

Thanks.


B. Wayne Turner
City of Winston-Salem
Utilities Division
phone: (336) 747 8418
email: waynet@cityofws.org



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