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Re: [GreenYes] Single-stream ergonomics
There are a series of issues that need to be looked at with single-stream.  One not yet mentioned in any of the discussions is cost.  From the studies that we have conducted in Saint Paul, MN, the single stream collection and processing system is the most expensive system of all of those currently operating.  Due to residuals, it is also the system with the least overall recovery of materials.  The issue of automation that "single stream"provides that reduces repetitive motion injuries can be applied to two-stream facilities as well.  A optical sorter that Eric keeps espousing is perfectly appropriate for a two-stream program as well.  Single stream systems without optical sorters are already more expensive then two stream systems.  Also, all of the single stream facilities that we surveyed in fact have more sorters per ton of material processed, not less, than two stream facilities.  Most of these additional sorters are working in pre-sort stations pulling out garbage and other contaminants that are getting into the stream.  This is due to automated collection of carts in which collection staff no longer have the same level of quality control ability or responsibility that they had in bin programs.  Is that presort job any more enjoyable/valuable then any other sorting jobs that currently exist, because they are the bread and butter of most of these new facilities.
The only new"automation" in the single stream facility compared to the two stream facilities is that there are screen that separate the containers from the fibers.  After that separation the single stream facility, low and behold, is a two stream facility.  Any automation that occurs after that point can be applied to either a single stream or two stream facility.  Currently, almost all new single stream facilities do not do anything different after that separation point then  any two stream facility.
Eric, iI am not sure why you keep referring to the decrease in manual sorting that you feel single stream provides.  Maybe it's a "grass is greener" issue since you are currently operating a two-stream facility.  The automation issues that single stream really addresses are at the curb.  The single stream processing facilities are just reponding to that automation, not creating new efficiencies of their own.

   All of our infoprmation strongly supports two-stream weekly collection of materials in bins when looking at costs and overall recovery and convenience to the residents.  We have a full study report posted at our website @   


Tim Brownell
President/Chief Operating Officer
Eureka Recycling
624 Selby Ave
Saint Paul, MN  55104
651-222-7678 ph
651-221-9831 fax

Eureka Recycling, an affiliated nonprofit of the Saint Paul Neighborhood Energy Consortium,
focuses exclusively on waste reduction and recycling services, programs, education and advocacy.

>>> Eric Lombardi <> 04/26 11:50 AM >>>
Hi all,

I need to weigh in and support Roger on this.  My 16 years of MRF design and
has always been on a path of greater automation and less manual sorting.
And just in the
last few years, optical sorting technologies have matured to the point that
I see great leaps
forward in the next generation of single-stream facilities that will greatly
reduce the need
for manual sorting.  And before anyone gets upset about losing jobs to
machines, ask
yourself if you would put your kid up there on the line doing that job.
These are not great jobs,
and the potential for repetitive motion injuries is real if someone does the
work for too many
years.  That's another reason why we use all-volunteer, short-term (under
six months) people
("mates") from the County Jail.  They are eager to earn time off from their
sentences, they like
the idea of helping the environment (for many of them they've never touched
the "environmental"
movement) and we've even hired some of them after they get out.  My main
point here is not
about using inmates ... I am just supporting the movement toward automation
and single-stream,
recognizing that producer responsibility with teeth is also essential for
incentivizing industry to
redesign their products and packaging to be less toxic, and more recyclable,
compostable and
re-usable, and, for addressing the "public subsidy" issues that Helen brings

Eric Lombardi

-----Original Message-----
From: Roger Guttentag <>
To: <>
Date: Thursday, April 25, 2002 10:06 PM
Subject: Re: [GreenYes] Single-stream ergonomics

>Going to single stream processing does not necessarily mean that there will
>be more people exposed to repetitive motion injury.  If we are talking
>a system design that is nothing more than a long sorting coneyor belt (and
>those systems unfortunately do exist) with scores of sorters positively
>sorting all materials, then I suppose this situation will occur.  However,
>current single stream system designs that I know about rely heavily on
>mechanized separation systems to make the concept work (e.g. separating
>fiber from non-fiber materials).  Whatever manual sorting is involved is
>either the same as what would be found in two stream sorting systems (e.g.
>positive manual sorting to remove a desired material from the sort line)
>quality control sorting (e.g. catching misses) which should not require as
>many movements per minute (otherwise it wouldn't be QC work).
>It should be noted that certain MRF sorting systems that have been adopted
>within the last 5 - 7 years have actually reduced the amount of manual
>sorting required.  One notable example is the use of star or disc screens
>positively sort OCC from OCC rich loads.  What used to take a team of
>sorters (let's say 6 - 12 laborers) to process a load now requires a
>with one (or two at most)QC sorters.
>Roger M. Guttentag
>----- Original Message -----
>From: Van Calvez <>
>To: <>
>Sent: Thursday, April 25, 2002 7:36 PM
>Subject: Re: [GreenYes] Re: 2002 Recycling Today Paper Recycling Conference
>> Here are 2 more cents on the single stream concept.
>> As an ergonomics professional, I have seen the impacts on having the
>> "professionals" do the work that the individual homeowner could do.  We
>> talking some pretty repetitive jobs here.  This generally spells high
>> of repetive motion injuries (and a crummy job in general).
>> Van Calvez
>> Human Nature Solutions
>> Bainbridge, WA
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