High commodity prices boost landfill mining prospects
Landfills contain tons of commodities that could be
recovered. While much of the technology needed for mining landfills is
already proven, the process is not yet economically feasible. But thanks
to record commodity prices this may soon change.
“At some point the land upon which landfills are located will become
too valuable to leave as landfills. The materials in the landfills -
especially aluminum, copper and some plastics - will become valuable
enough to make the mining, recycling and land rehabilitation processes
attractive,” said Patrick Atkins, president of Atkins 360 LLC in Pittsburgh
and an advisor for Pegasus Capital Advisors, a private equity fund.
Before joining Pegasus as an environmental consultant last year, Atkins
was the director of energy innovation at Alcoa, Inc., the Pittsburgh-based
aluminum producer. He was responsible for identifying and supporting
alternate energy sources for Alcoa.
A handful of states investigated the feasibility of mining landfills
last decade. But the idea has basically been dormant since then. Atkins
said no one is currently working on landfill mining on a commercial scale.
But with prices of many commodities hitting new records he thinks this
might change. “This is an idea that requires careful economic review,
and will not work in all cases, but it could be a winner in many settings,”
The lack of technology is not the problem. There are already economical
processes to re-melt aluminum for example. There are also processes used
to separate aluminum from solid waste before incineration, such as an
eddy current magnet that deflects aluminum from a flowing stream of material.
But Atkins said the two processes have not yet been put together to separate
aluminum from mined landfill material.
Atkins estimates that aluminum is about one quarter of one percent of
the material by weight in municipal landfills. Each year in the United
States about half of the 100 billion aluminum cans used are lost to landfills,
he said. At 30 cans per pound that amounts to 1.5 billion pounds of aluminum
“At $1.25 per pound of aluminum, the value is significant,” Atkins said.
Atkins’ former employer, Alcoa, is not interested in mining landfills
for aluminum at the moment. Kevin Lowery, a spokesman, said Alcoa has
instead invested significantly to expand its recycling capability and
capacity. “The biggest opportunity – and the more efficient one – would
be to get the material before it goes to a landfill,” Lowery said.
It is not only aluminum, however. There is steel, copper, plastics and
other materials of considerable value in landfills. Plus the land itself,
usually near or in cities, is of considerable value, Atkins said. Plus,
many landfills are being tapped to collect the methane gas that is being
generated as anaerobic bacteria degrade the organic material.
“This process of converting the organic components could also be accelerated
by the mining process, using controlled reactors to produce the gas rather
than relying on the more open, natural processes, which result in lower
British thermal units,” Atkins said.
Reid Lifset, associate director of the Industrial Environmental Management
Program at Yale University has done research on landfill mining. His
research focused on copper in landfills. He said that the economics behind
the process are not yet favorable.
“Most efforts at landfill mining reflect circumstances specific to a
particular location or facility,” Lifset said. For example there may
be need for fuel to fulfill a put-or-pay contract at a waste-to-energy
plant or a need to delay a landfill closure.
“Our research told us that with current technology and prices, landfill
mining is generally not economically viable - the benefits such as revenue
from sale of recovered metals, reduction in regulatory costs, generally
did not outweigh the costs,” he said.
Copper mines are extremely large enterprises allowing for the use of
gigantic equipment that results in economies of scale. “Landfills, especially
older ones, tend to be much smaller,” he said. “The copper in landfills,
while large in aggregate, is widely dispersed across many locations,
making it harder to realize similar economies of scale.”
Because costs would often outweigh benefits, Lifset said that landfill
mining on a commercial scale would probably not catch on in the near
future. “We have not ruled out the mining of landfills. But we do not
see it as likely in the near term,” Lifset said.
Higher tipping fees might make the process more economical, however.
Or higher costs for landfill closures might help. Also, if the prices
for secondary materials increase further, it might make landfill mining
more feasible, Lifset said. “The single largest thing that could enhance
landfill mining would be a breakthrough in the cost of processing.”
Lifset said his research found that landfill mining is not typically
motivated by materials recovery in the traditional sense. Instead, landfill
mining is often motivated by more than one goal. Projects would therefore
be more viable if they accomplish more than one thing – for example,
recovery of metals, provide fuel for a waste-to-energy facility, postpone
a landfill closure and remediate landfills with environmental problems.
“Most projects will only find a small subset of these benefits to be
relevant,” Lifset said.