Nageezi is a small settlement on
the far eastern side of the Navajo Nation in northern New Mexico.
It’s classic high-desert country, with ponderosa pines and
sagebrush and beige cliffs, along with the smattering of run-down
housing so often seen on reservations. But among the trailers and
tract homes sits one unusual structure, the kind that
wouldn’t seem out of place in a chic Santa Fe neighborhood.
Its walls are stucco, and in its courtyard, a pergola shaped like a
hogan faces the rising sun.
Mary and Kee Augustine,
Navajo elders, live in this home, which was built in 2005. For 35
years before that, their “home” was a 1960s cinderblock
box. Its foundation was crumbling, it lacked insulation, and had
bad heating and a leaky roof. This new home is comfortable, cool in
the summer and warm in the winter, and it was designed with Navajo
tradition in mind. It was made possible by a partnership between
the Arizona State University Stardust Center for Affordable Homes
and the Family and the Navajo Housing Authority. It was also made
possible by flyash – the nasty gray soot that’s left
over after burning coal.
Each year, along with all the
pollution they put into the air, coal-fired power plants in the
U.S. collectively regurgitate some 129 million tons of solid waste,
about half of which is flyash. Both the sheer magnitude of the
waste and its composition – it can contain high levels of
various toxins, including selenium, arsenic, mercury and lead
– make it a challenge to deal with. While power plants near
surface coal mines can just dump the stuff back into the mine,
other plants have a tougher time figuring out what to do with all
of the junk. And a push by activists for stricter federal
regulations could make things even more difficult, even for those
who dump into the mines.
In Page, Ariz., however, the
Navajo Nation’s housing authority has taken a novel approach
to utilizing the stuff. In 2005, it opened the Navajo FlexCrete
plant just a stone’s throw from the gigantic Navajo
Generating Station. There, the company uses flyash from the power
plant to create building blocks for homes.
The main
structure of the Augustines’ Nageezi home is made of
FlexCrete blocks. They look, at first glance, like conventional
concrete cinderblocks, but they’re not. They are solid and
much lighter than concrete and, because they are aerated, provide
their own insulation. The blocks are between 60 to 70 percent
flyash; the rest is a combination of nylon and conventional cement.
Using flyash in place of cement isn’t unusual; in
fact, people have done it since Roman times. Today, some 15 million
tons of flyash go into concrete products each year, with that much
again recycled for other uses such as road base. But the Navajo
FlexCrete plant uses more flyash in its product than many other
companies, giving the power plant one more place – aside from
a landfill — to put its ash. According to Paul Ostapuk, an
environmental engineer for the Navajo Generating Station, that
helps the plant recycle 80 to 90 percent of its flyash (currently,
only a small portion goes to FlexCrete, with the rest shipped to
cement companies around the region). The average U.S. coal-burning
plant only recycles about 40 percent of its ash. And, since
manufacturing one ton of Portland cement kicks nearly one ton of
greenhouse gases into the atmosphere, using flyash in place of
cement helps air quality.
That’s not to say that
the enviros are all holding hands and singing “Kumbaya”
over all ash recycling. “Not all ash reuses are created
equal,” says Lisa Evans, an attorney for Earthjustice who is
an outspoken proponent of stronger regulations for disposal of coal
combustion wastes. Sometimes, the stuff is used as road base, or
even spread on icy roads for safety, which risks introducing
particulates and potential toxins into the environment. Meanwhile,
some flyash has been found to be mildly radioactive –
depending on the source of the coal – which concerns Evans.
But generally, she supports projects like FlexCrete, as long as
tests show that the ash is not radioactive.
Jim Shirley,
Navajo FlexCrete’s plant manager, says toxins are not a
problem with his product. His company uses only the
“cleanest” portion of ash, and it’s all tested by
Arizona State University for contaminants before it’s used.
The plant produces some 2,000 pallets of bricks each
year, which have been used in houses from Phoenix and Flagstaff,
Ariz., to Durango, Colo., to Santa Fe and Nageezi, N.M. Shirley
says the company is hoping to soon establish distributors in
Phoenix, Telluride, Colo., and possibly in Utah.
Daniel
Glenn, Stardust’s design director, hopes to expand his
organization’s use of FlexCrete because he considers it a
local, green material that fits Stardust’s criteria for
building affordable homes. He also likes it because of it has a
high insulation value, and discourages both termites and fire. In
addition to the Nageezi home, Stardust has designed and built a
home with FlexCrete in Guadalupe, Ariz., one of the poorest
non-reservation areas in the country, and is hoping to use the
blocks for a 200-home project on the Salt River Pima Reservation in
Arizona. Meanwhile, Glenn and his colleagues are working with the
Navajo Housing Authority to create a prototype of a FlexCrete home
that can be mass-produced on the reservation.
“We
need to find ways to build with local materials,” says Glenn.
“We can’t rely on importing materials from other
regions.” With Western power plants pumping out some 17
million tons of solid coal waste each year, ash is one regional
material that’s not in danger of running out.
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