Life & Limb: Process Could Aid Removal of Contaminants from Iowa Soil
Cedar Rapids Gazette
March 23, 2008
NOTE: Louis Licht will discuss opportunities for using phytoremediation to reduce agricultural pollution and improve on-farm energy independence at an April 28 University of Iowa conference: Keep it Small; Keep it All: Cultivating the Bioeconomy at the Local Scale. Click here for more information.
By David DeWitte
NORTH LIBERTY — The founder of a Corridor business that led a revolution in the use of trees to clean up soil contamination sees a bright future for trees in making Iowa agriculture greener and more energy independent.
Fast-growing poplars consume copious amounts of water. A 1-acre poplar grove only three years old can extract more than 800,000 gallons of water from the soil annually.
Microorganisms that live on poplar roots can digest many toxins in the soil. That’s of particular interest in Iowa, where there are concerns about the disposal of sludge from waste lagoons on hog farms and contaminants under “brownfield” sites in urban areas.
The poplar’s unique ability to grow roots from a planted stem makes it possible to plant the trees at considerable depths.
The combined characteristics create what Licht calls a “root zone reactor” that can be used to clean up a specific amount of land based on the number of poplars planted.
While the potential to use poplars to remove soil contamination seemed clear to Licht, it lacked credibility with environmental regulators. Licht began a research program at the University of Iowa with Jerry Schnoor, a professor of civil and environmental engineering, to fill the breach in scientific knowledge.
With an entrepreneurial attitude he attributes to his upbringing on a Lowden farm, Licht incorporated Ecolotree Inc. shortly before graduating in 1990.
Since then, the little North Liberty company has designed and installed pollution cleanup systems using poplar trees at more than 100 sites in 29 states.
The use of trees for soil cleanup is known as “phytoremediation.” Licht’s contributions to the process earned him the UI Hancher Finkbine Medallion, two awards from the National Professional Engineers Council and multiple awards from Fortune 500 companies for successful cleanup projects.
He even gained a splash of celebrity in 1999 when People magazine featured him in a two-page article.
Ironically, Ecolotree hasn’t gotten much business in its own backyard.
Beginning in 1993, it worked with the former Bluestem Solid Waste Agency on plans to use a tree cap or “eCap” on the Cedar Rapids landfill known locally as Mount Trashmore. The agency eventually rejected planting the trees as part of the cover for the landfill when it closed, but Ecolotree’s research on the project was put into practice installing poplar trees on a Pennsylvania landfill 16 months ago.
Ecolotree continues to find new uses for the process.
One recent project that captured the imagination of central Wyoming residents was a three-acre “oasis” planted in the arid, treeless Wyoming plains from Iowa-grown poplar saplings. The oasis was created to dispose of sodium from 10 million gallons of polluted water that had been extracted from coal seams during the development of methane wells.
Licht and his Ecolotree crew returned this month from a three-state trip in which Iowagrown trees were planted at a Florida utility for arsenic control, an Ohio meat packing plant to control odor and an Indiana farmers co-op that needed to clean up pollution from a demolished fuel depot.
In one week, Ecolotree will install an irrigation system in a 6-acre poplar tree cap to clean up 40,000 gallons per day of fluid leaching from a landfill in St. Louis.
Eventually, Licht says, the same process could be used to irrigate urban waste water from Iowa towns.
The biggest change Licht has seen since 2000 is a change in attitude among mainstream Americans toward energy selfsufficiency, fossil-fuel greenhouse gas emissions, and air and water pollutants from agriculture. That has translated into new projects and promising new uses for phytoremediation.
“People are thinking more holistically and strategically,” Licht said.
Understanding the larger picture and spending on environmental efforts where it produces the greatest impact will be the key, Licht says. He points out that just 2 percent of the watershed surface of the central United States controls 80 percent of the pollutants that drain into the Gulf of Mexico.
That 2 percent is located in four spots — downhill from tilled soil, downhill from manure, downhill from urban runoff and at waste water treatment plant discharges.
Licht says poplar plantings on these strategic lands could be periodically harvested. At current oil prices, Licht says the economics of chipping the wood and using commercially available methods to make onfarm heating fuel are extremely interesting.
An annual poplar harvest can be worth $1,000 per acre if it displaces liquefied propane gas for grain drying or heating homes, Licht said.
Key to installing poplars on Iowa farms, Licht says, would be developing incentives so that the trees compete with row crops like corn and soybeans.
Besides the value of using the trees for fuel, Licht says the poplars could generate revenue through carbon credit trading and pollution credit trading.
“If we can have a fuel that we can grow here, and produce here, and move it over 3 feet and use it, that’s much more efficient than what we have now,” Licht says.
Licht is getting more involved in spreading his message, serving on a platform committee for the Johnson County Democratic Party on agricultural issues. He’s also working with school districts to develop science curriculum to involve students in projects that will combat climate change.
Licht also is pursuing grants to fund research on a phytoremediation approach to treating municipal sewage.
“I’ve been chasing this thing since 1979,” he said. “You could do a lot of things with this.”
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This October photo shows the Windsor Energy site near Gillette, Wyo., where water extracted from coal bed methane wells irrigates a poplar grove. The grove was planted by Ecolotree to remove sodium from the irrigation water, and a local newspaper dubbed it “the oasis on the plains.”
Louis Licht (right), founder and president of Ecolotree of Iowa City, explains the process for a new technique for decommissioning swine waste lagoons in December 2003 at Hanor Farms in Whitakers, N.C. After years of struggling with the dirty disposal problem of sludge from hog waste lagoons, researchers have come up with a possible green solution — poplar trees that suck up the waste like soda straws.
An Ecolotree crew plants a poplar tree “Ebuffer” at a utilityowned manufactured gas site in Fond du Lac, Wis., in May.