|The economics of earthbags
vs. cinder blocks
(CMUs, or Concrete Masonry Units)
(see links at
bottom of page for references)
14" x 26"
14" x 26"
x 8" x 16" concrete blocks
per 100 lbs:
coverage per 100 lbs:
||3 cubic feet
jute or hemp
|Common chemical byproducts in manufacturing:
ox0-alchohols, carboxylic acids
lead, arsenic, cadmium, chromium, molybdenum, hydrochloric
acid, sulfur dioxide, hydrocarbons, ash particulates - released into air, storm drains, and groundwater
term impact to environment:
decomposition can lead to minute airborne distribution of tiny fibers
is typically deposited in landfills, leaching chemicals (such as mercury)
into soil, groundwater, aquifers & waterways
cement industry, both nationally and internationally, is under fire
& sweating bullets in ways it's never before imagined.
Starting in 2007, revelations about the industry's
"hidden costs" began
to receive some wide
mainstream reportage & investigation.
- Portland cement manufacture is
responsible for some 5% of CO2 emissions worldwide.
- Portland cement manufacture is the 4th
largest source of mercury contamination in the US.
- Portland cement kilns are phenomenal
energy consumers, needing to be heated to temperatures of 2,700-3,000
degrees Fahrenheit in order to convert raw materials into their end
- Under the auspices of the EPA,
many cement manufacturers have been using highly toxic waste to fuel
their kilns - the belief being that the high heat destroys or breaks
down the toxins & pathogens. Some "reasonable
excessive emissions have been permitted in a "greater good"rationale.
- Air emissions from portland cement manufacture
to as CKD, or cement kiln dust) contain - besides mercury -
hydrocarbons, hydrochloric acid,
sulfur dioxide, particulates,
and various heavy metals, including arsenic, lead, chromium,
cadmium, and molybdenum.
used in the manufacture or portland cement
a pH value of 12 or above, making it phenomenally caustic.
unconstrained runoff & incidental seepage enters the
soil and sewer lines, and ends up
in groundwater, aquifers, and waterways.
response, the concrete industry in this country has joined forces and
formed the “Concrete Sustainability Initiative” – under the auspices of
the WBCSD (World Business Council for Sustainable
Comprised of some 200 multinational corporations, it enjoys privileged
seats (and major influence) with the World Bank, the WTO (World Trade
Organization), the IMF (International Monetary Fund), and the OECD
(Organization for Economic Cooperation &
of the WBCSD includes corporations such as Alcoa, Chevron, General
Motors, DuPont, 3M, Deutsche Bank, Coca-Cola, Unilever, Gazprom, BP,
Wal-Mart and Royal Dutch Shell.
To give the concrete industry credit, they are (after having the
on the wall read to them) actually making
some progress in reducing emissions & releases, and even coming
with some alternative methods & materials (such as using rice
hulls) to create “greener” concrete.
- as is so often the case -
(not token) environmental reform tends to be
a great deal of foot-dragging, court appeals, dithering about the data
produced by "our experts" vs. "their experts". In the meantime, the
industry continues to -grow, and their chief sense of
responsibility remains to their stockholders - which translates into
reducing costs by all feasible means in order to maximize profits.
Despite whatever present or future regulations that domestic concrete
may find itself forced to comply with, countries like
China & India are still thumbing their noses at the global call
reduction in emissions. Worse, many Western concrete
manufacturers, finding that they can’t keep up with ever-more-stringent
regulations at home, are going to Eastern Europe and Russia and the
Ukraine, buying old cement plants for a song, and skirting
Where do those $1.00 concrete blocks at Home Depot and Lowe’s come
they’re made domestically, then the true cost must include the impact
water, our fish & wildlife, our health, and our
energy consumption (with the result of frantic calls by politicians for
more coal-burning & nuclear power plants).
On the other hand, if these "big box" concrete
blocks are made
overseas, then their true cost is
the impact to the environment and the infrastructure that
the people of the countries in which they're made, plus immense
to ship them to American ports and then truck them over American
highways (more pollution)... notwithstanding that they may contain materials not sanctioned for domestic manufacturers.
Where do cinder blocks go when they die? Broken
into rubble, they're dumped in solid
waste landfills all around America (landfills themselves facing a
crisis), where mercury and other
contaminants are leached into water
tables (our drinking water) and streams. For a disturbing look at some
of the causes behind the epidemic rise in breast cancer, click here.
We think earthbags make a lot more sense. While
the polypropylene bags are admittedly made of petroleum-based plastic
polymers, the amount used per bag is modest, and (if not plastered
over) they are recylable
(Resin Identification Code 5). Burlap bags are fully biodegradable.
In terms of mass, 1,000 empty polypropylene bags (at about 85
lbs, capable of building approx. 2,583 cubic feet) weigh less than
three 8"x8"x16" cinder blocks (at about 90 lbs, capable of building
approx. 1.8 cubic feet) .
While both poly & burlap bags are sourced
from Asia, and carry
a carbon footprint based on manufacture and transportation to North
America, this too is negligible by comparison. The only way to
improve on polypropylene earthbags as a modular construction component
is to hope for the development affordable vegetable-based polymers
(pending), to use burlap or hemp bags, or to forego using bags
altogether & use adobe bricks or rammed-earth construction.