Clean or dirty?

greensort
On a recent visit to Hartsfield (Atlanta’s airport) I noticed that there were no recycling bins.  On closer inspection, and a little research, I realized that these were absent due to a new program they’ve introduced starting in November 2009 which lets customers dump whatever they want into the trash bins and the “sorting out” is done by the airport (actually a partner – read more below).  This got me wondering as to whether or not this was effective.  Sure enough I now know that although this has some advantages (see the press release by Hartsfield), it does have some problems.

ATL (the familiar three-letter-code for Hartsfield) generates nearly 70 tons of paper, plastic, food and other trash daily.

70 tonsDaily! That’s a lot of Nathan’s hot dog wrappers.  So indeed, steps taken to improve how much of this ends up in landfills are important steps.

Here from the press release is some of the benefit from this step:

“All waste generated by passengers, employees and businesses goes into the same container and is taken to a facility, where it is sorted and recycled. The Airport plans to reduce the amount of trash it sends to landfills by 50 percent by the end of the program’s first year — and by 70 percent by the end of the second year.”

Solid-waste handling company Waste Pro USA transports waste via an alternative-fuel truck to a material recovery facility (MRF), where it is sorted. All recyclable materials are recycled, and the rest is sent to landfills.

So this is a good thing, right?

Not necessarily…

An anonymous post to the article promoting this program goes like this:

“This process is what is known as a “Dirty MRF”. This is not the solution to recycling. Much of what could be recycled will end up in the landfill because it is ruined by waste. Single-stream recycling was introduced a few years back and it is a simple, easy solution to recycling. One container for recycling and one for waste. My request is that the busiest airport in world be a true leader in sustainability. A Dirty MRF concept is not impressive.”

This led me to an interesting description of a “dirty MRF” (which sounds much more intriguing than it is) at a very informative site on Mechanical and Biological waste treatment. There I found the table below – of strengths and weaknesses of Dirty MRFs.

So it comes down to a philosophical discussion of whether or not the technique of letting people throw anything into the bins actually gets more waste into a stream that may be able extract recyclables, outweighs the amount of energy and time in the sorting, and the amount of trash that ends up in landfills anyway.  Does anyone else out there with more knowledge and experience want to “weigh in” ?  Could we get someone from Hartsfield or Waste PRO USA to comment?

Strengths Weaknesses
Extracts additional recyclables from residual waste stream Low quality of recyclables output can render material of low value.
Generally lower capital costs compared to clean MRFs (per tonne equivalent) Unless there is a high level of separation in the plant, there is likely to be a major component of the waste entering the plant going to a disposal facility (landfill or energy from waste).
Can be used as part of an integrated system to gain energy and materials value out of the residual waste stream Where materials are divided for example into biodegradable and combustible material streams, the facility is reliant on the availability of other waste management operations.
Lower cost than MBT whilst achieving similar aims (although potentially less effectively) Potential dust / odour problems and health issues for staff on picking belts
Applying proven technology Any biodegradable stream derived from plant will be subject to the Animal By-products legislation
Outputs from the plant will still be classified as BMW under the Landfill Directive and active waste under Landfill Tax

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