comment/request, at http://www.insinkerator.com/environmental.shtml
you will find six contemporary studies – beginning with the UWisconsin
(’98) which Carol Diggelman conducted (later published in “Waste
Management and Research”) and ending with last year’s report (exec
summary) on the “Sink Your Waste” initiative in
Herefordshire/Worcestershire County cited in the WSJ article – along
some commentaries. The study from Sydney
also independently assessed four options for food scrap management.
Additional studies and commentaries are available from me, upon
request, as is
a comprehensive document summarizing findings – by topic, to make it
to find particular answers – from seventeen (17) studies, for those who
really want to dive into this topic.
worth noting that in the U.S. food waste
disposers daily divert millions of tons of food scraps from solid waste
transport and disposal systems. Probably fair to say that even in the
Area that disposers daily divert a significant amount of residential
scraps – and have done so for decades. After all, not much
difference between food and human waste – both @ 70% water, with
chemical composition. Plenty of studies of impacts/benefits re
treatment systems, but there’s also substantial evidence in the form of
the ‘wisdom of crowds’ of nearly all municipalities in the U.S.
chosen to allow disposers for decades. Dave Biddle’s Philadelphia is
example, where commercial disposers have been encouraged for @ 15
part to reduce odors and vermin caused by food waste stored in
point of the WSJ article is that where
disposers are not common for historical reasons, and pressure is
find effective answers, that municipalities are now making informed
about how best to manage food scraps, with some choosing to trade
in/reliance upon wastewater treatment plants and biosolids processing
collection and the challenge/cost of siting/operating composting
The article didn’t mention it, but that’s essentially the analysis
that led NYC in 1997 – after a decade of study – to fully permit
residential disposers (previously legal only in newer areas), and is
now in the
midst of studying the efficacy of commercial disposers for the same
albeit with a new imperative: of reducing GHG emissions from whatever
system is pursued, vs. continuing to ship 5,000 TPD of residential and
food waste to distant landfills.
As to Dan’s
concern about sewer
overflows, that issue exists with or without disposers; the added flow
disposers is less than 1% per daily household water
In mass balance terms, using NYC as an example, its WWTPs daily handle
billion gpd; if ALL 3 million homes had and used a disposer, the added
would be perhaps 5 million gpd, or a de minimis impact – in the words
February 28, 2008
To: David Biddle
Cc: Dan Knapp; Kendall
Growing Global Interest in Food Waste Disposers
Note that the WSJ article, which I read, was not a glib endorsement but
just a descriptive report of what's happening in Malmo, Sweden
- and a few other European cities. The garbage disposall was invented
in the US
marketed here wth the post-WW2 housing boom - 50% mkt penetration now.
never had much mkt in Europe but now is being positioned as a green
there as limits of successful backyard composting are being reached in
like Germany that have done it for a while. The article reports on a
Carol Diggelman in '98 looking at 5 different ways of managing food
concluded that disposals that fed to water treatment plants w/
recovery had a more benign enviro. footprint than trucking food waste
to LFs or
even to compost fcilities. anyone have a copy of tha study? Would love
the discussion in that.
David Biddle wrote:
Kendall-I would love a copy
of the WSJ
Dan- It seems to me that the problems that biosolid systems are having
country are more a function of a dilapidated or under-sized
that this issue calls forth the need to seriously examine that
Also, in your climate backyard composting is probably a bit more doable
northern climates like Philadelphia, Boston, Chicago,
etc. In addition, in many cities people don’t have space, literally.
in Philly the majority of backyards are postage size. Finally, in
seen, while the residential food waste component is high, the
institutional fraction is much higher. Short of daily collection of
carts, what is a Hilton Hotel supposed to do with their 2,000+ pounds
scrap and sauces?
I’m advocating (and Kendall and I have talked about this often) for a
very careful and thorough analysis of all the options for really
problem, especially for the commercial sectors. If it means that cities
look at renovating with $200 million bond options or privatizing their
or whatever, then so be it. Certainly, if the Bay Area is struggling
you say it is, this process must already be underway. I would hope all
Waste-Heads their are looking to be a part of the solution.
David Biddle, Executive
Commercial Recycling Council
Philadelphia, PA 19118
on 2/28/08 4:16 PM, Dan Knapp at firstname.lastname@example.org
that sewage treatment plants in the San Francisco Bay Area would not be
enthusiastic about the WSJ's glib endorsement of garbage disposals to
solid waste. I have read several articles in the local press about how
these plants are so maxed out that they are sometimes forced to dump
sewage into streams that drain to the Bay. In late January one major
sewage release in Marin County amounting to millions of gallons was one
lead stories on the evening news for a couple of weeks. Following that
spill, lots of dead shorebirds were found in the area, although no
link was established. Also, sewage treatment facilitiy operators are
advising customers via mailings never
to put grease into the sewage system at all, since it creates pipe
not to mention lots of Biological Oxygen Demand.
The best option is to compost food in your own backyard along with all
trimmings, food paper, and other organics such as cotton clothing.
done it for decades, and it's very satisfying, especially when combined
growing food in the enriched soil you get when you actually use the
compost. My soil horizon in the food garden is now about eight inches
deep after fifteen years of soil amending with dozens of cubic yards of
I'm also taking carbon that used to be in the air and putting it into
where it nourishes the soil critters and fungi that help plants grow.
soil is much easier to work than the heavy clay that I had to start
clods at all, and it holds water like a sponge.
Next best is to use curbside food and yard debris collection; these
processing systems are proliferating all over the Bay Area right now.
Urban Ore, Inc., a reuse and recycling business in Berkeley, CA
for 27 years.
On Feb 28, 2008, at 11:54 AM, Kendall Christiansen wrote:
the Wall Street Journal featured a report about the growing
interest – with a focus on the EU – in the efficacy of food waste
disposers (aka garbage disposals) as an environmental management tool,
immediate diversion of food scraps from the solid waste stream, and
wastewater treatment plants to process the solids in fertilizer
energy recovery where possible. In particular, it noted the experience
several cities that have intentionally opted for disposer-based systems
food scrap management.
Given that the WSJ remains subscription-based, if you’d like a copy of
the article – as well as its Environmental Capital blog post on the
topic – please let me know and I’ll forward. If you would
like access to one or more of the reports referenced in the article,
know that, too.
151 Maple Street
Brooklyn, NY 11225
writer is senior consultant on
environmental affairs for InSinkErator, the leading manufacturer of
and commercial food waste disposers, and former Chair of NYC’s Citywide
Recycling Advisory Board