What if you could use plants to turn industrial waste sites into fertile, productive cropland? Better yet, what if you could produce biofuels in the process? By marrying bio-remediation and crop production, a group of Carnegie Mellon University graduates hopes to do just that: produce biodiesel and ethanol on reclaimed land.

"It’s a proven technology, but in an unproven environment," said Mr. Butcher, 27. "The idea of growing energy crops is not necessarily a new one; the idea of growing them on distributed sites on vacant land, in an urban context, is kind of a new idea."

Kind of. It’s happening elsewhere, in dribs and drabs. Monroeville’s Cardinal Resources plants poplar trees, which suck up toxic waste, at manufacturing sites around the country, but doesn’t convert those plants into fuels. In Los Angeles, a design team funded by the Annenberg Foundation has turned a 32-acre rail yard into a massive cornfield and garden. But that project, dubbed "Not a Cornfield," is more urban artwork than laboratory. The closest parallel can be found in Michigan, where Michigan State University researchers are turning a 2-acre dump site into land for biodiesel and ethanol crops.

Using plants, enzymes, fungi, or microorganisms to depollute contaminated areas isn’t an entirely novel concept. Phytoremediation - using plants to clean up the soil - has been practiced for centuries. Due to general increases in industrial pollution and the sheer potential of the idea, using naturally and (more recently) genetically-engineered organisms to ameliorate pollution has gained special emphasis in the last 20 years.

The CMU group is taking the next logical step in bioremediation by attempting to create a usable byproduct, in this case fuel:

GTECH [Growth Through Energy and Community Health], a nonprofit that sprang out of a master’s thesis, is hoping to bring all of the divergent threads together, stitching a strategy that will cleanse contaminated industrial land, occupy vacant urban plots and produce renewable fuels, the last of which happens to be one of the hot political topics du jour.

Test crops already have been planted. At the former LTV Steel site in Hazelwood, the GTECH crew has taken over six barren acres of fill and planted hybrid poplar trees, switchgrass and sunflowers. The first two can be reduced into cellulosic ethanol — that is, ethanol that isn’t corn- or grain-based — while sunflowers become conventional biodiesel.

Testing several types of crops is important, since each plant removes different contaminants. For example, ragweed and poplar trees sequester lead. Barley and sugar beets excel at removing salt and have commonly been used to desalinate agricultural land. Naturally occurring bacteria can be harnessed to assist in cleaning up oil spills. And sunflowers are apparently well-suited to remove arsenic and uranium from soils - just in case you had a chemical explosion or a nuclear meltdown.

It’s also important to find crops with properties conducive to making biofuels. Growing ethanol- or biodiesel-producing crops on contaminated land bypasses the food vs. fuel issue and could make more land available for cultivation.

But it isn’t clear that any of these crops will actually work for the intended purpose, especially on really polluted sites. Will it take a succession of several different crops or polyculture to fully remediate the soil? Will the plants even grow under such poor conditions? And more importantly for the project, will the biofuels meet ASTM fuel standards, considering the contaminant load they could contain?

"We’re not growing on even farmland, which is hard enough to grow on," said Ms. Koch, 33. "We’re growing on vacant properties, which are usually demolished houses that have brick and glass and cement and rebar and all kinds of terrible things. [Crop] quality is going to be a concern," especially in the first years. It’s a concern at Michigan State, too. Will the end product meet industry standards — and, should they come to pass, federal standards — for what makes usable biofuel?

Time will tell.  In any case, it’s a great idea, and the group deserves a nod:

"You’re going to see a lot more land, whether it’s a brownfield or otherwise, get utilized for crops like that. I wouldn’t be surprised to someday see all the highway grass be switchgrass instead," he said. Rather than paying PennDOT workers to mow grass along the sides of highways, farmers or biofuel companies might bid for the rights to harvest the switchgrass, which sprouts perennially and grows well in poor soil and cooler climates.

CMU grads want to use blighted industrial, residential sites to produce bio-fuel crops. July 10, 2007. Post-Gazette.
Wikipedia: Phytoremediation
Wikipedia: Bioremediation

Photo Credit: Post-Gazette