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RE: [greenyes] successful single stream programs
John,

I have a question as to what you define residuals to be in the sort that
you conducted. Are the "residuals" in the sample sort you cite of 6.48%
the materials that are not accepted in your program? Did you conduct the
sample sort after collections, but before processing? 

We define those materials in the Eureka Recycling pilot study in Saint
Paul as "outthrows". If that is what you are saying are residuals, then
I would say that our study in Saint Paul had consistent findings in the
single-stream pilot. We had a rate of "outthrows" from the single-stream
pilot of approximately 5%. 

However, residuals as defined by our study were the combination of
"outthrows" with the materials that were too contaminated/commingled
after processing to be shipped to any viable market and had to be
landfilled, or used as landfill cover instead. Once those materials were
added into the quantity of "residuals", our study found the residual
rate to be approximately 27% on average.
   
Back to the issue of outthrows. What we also found as we talk to various
single-stream programs around the country, the longer that a single
stream program had been operating, the higher the amount of outthrows.
It appears that with the use of carts, there is less direct feedback to
the consumers/residents about what they are placing out for collection,
since the drivers are not getting out of the vehicles having to look
into the carts/bins, and no longer leaving behind materials or tags
indicating a problem. As time passes, the message seems to be that it
must be okay for the resident to place it out if it is gone when they
bring the cart back in. This is leading to significantly more
non-recyclable materials, or outthrows, entering into the stream. Los
Angeles is a prime example of this, but certainly not the only one. 



-----Original Message-----
From: John Brand [mailto:jbrand@no.address] 
Sent: Friday, March 28, 2003 12:25 PM
To: greenyes@no.address
Subject: [greenyes] successful single stream programs

 The City of Moorpark, California, has a single stream residential
curbside collection program. A characterization sort was done to test
the residual rate. The single stream residual contamination rate is
6.48%. With yard waste, the overall residential diversion rate is over
55%. Spot inspections of the yard waste found that residual rate was
negligible by weight, just the usual plastic bags. It was felt that the
low residual rate in the single stream program indicates Moorpark
residents have a good understanding of the program. Based on these
findings and other considerations, the City approved an automated
curbside collection system. We have a reasonable level of confidence
that automation will not result in greater contamination of the
residential curbside single stream collection. Automated three-cart
collection (discards, recyclables, yard trimmings) will be implemented
citywide by the end of June, 2003. Continuous education seems to be the
key. Complete recycling and disposal instructions are on the automated
carts, on the back of every bill, and sent to each household four times
a year inside the quarterly City Newsletter and Recreation Guide. The
info also occasionally scrolls on the City cable TV channel. A
"Recycling News" and other educational material are distributed at every
City-event and at all of the information kiosks at City offices.






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