Cedar Rapids Gazette: Ecolotree Leader Envisions New Era of Wastewater "Tree-tment"
North Liberty eco-business developing alternative to sewage treatment plants
The day could come when small Iowa towns have their waste water treated in dense groves of poplar trees planted at the base of wind turbines.
That’s the vision of Louis Licht, the president and founder of North Liberty-based Ecolotree.
“There’s hardly anything more efficient than using solar-powered trees to treat your waste water,” Licht said.
Licht isn’t kidding. His company is working with the Port of Morrow on the Oregon side of the Columbia River to obtain approval for a system to treat the plant’s waste water by using it for year-around irrigation of a poplar plantation.
Businesses on the port produce as much waste water as a city of 40,000. Their products include the Blooming Onions served at Outback Steakhouse and the French fries served at McDonald’s fast-food restaurants.
The port has been using the waste water for irrigation in the summer, but unless it can find a year-around solution it will face a very large tab for waste water treatment. A new waste water treatment plant would cost about $42 million, Licht said, and cost about $1 million in utilities per year to operate.
Even a waste water lagoon system would cost about $14 million to build.
If the year-around irrigation system gains regulatory approval, Licht said it will pay for itself by producing pulp wood that could be sold for a variety of commercial uses.
Ecolotree has been working since 1990 in the field of phytoremediation, using plants to remove contamination and waste products from soil.
Ecolotree works mainly with poplar, a species which pumps prodigious quantities of water out of the soil and into the air as it grows rapidly. The company is working on 22 projects in 15 states, most of them involving phytoremediation of things such as landfill sites and fertilizer spills.
Phytoremediation — Greek for “plant” and “restoring balance” — hasn’t gotten as much use in treating waste water, Licht noted. One reason is that environmental regulators don’t believe trees will process waste water in the winter months after their leaves have dropped and they are no longer pumping water out of the soil through transpiration.
Licht and other scientists in the phytoremediation field have long known that the treatment continues even after the leaves have dropped. That’s possible because much of the water is processed by microbes that grow in and around the plant’s root systems, which remain active year-around, Licht says.
To seek regulatory changes the Port of Morrow needed, Licht set about finding a way to prove the year-around benefits of using trees to process waste.
Licht adapted 36-inch-deep insulated shipping boxes to serve as test cells. He puts a drain in the bottom of each box and fills it with soil, then plants poplar or willow trees in the top.
Two months after they are planted, the boxed poplar trees that have been force-fed waste water have roots dense enough to mimic those of mature poplar trees. Every drop of water placed in the container passes within one centimeter of a root.
The port has funded research at the University of Iowa that can be peer-reviewed to provide a foundation of scientific consensus around the technology.
Researchers record the loadings of ammonia, nitrogen and other waste products poured into the top of the box, and compare it to the loadings in water draining out of the box.
The port planted 10 acres of poplar trees this year to pilot the waste water irrigation project, and will plant 30 acres before next growing season.
Licht called the Port of Morrow project a “sweet spot” for advancements in phytoremediation because it has all of the elements needed to bring phyto-based waste water treatment to a large commercial scale.
The site has a huge stream of waste water from the processing of potatoes, onions and other foods. It has the nearby ZeaChem cellulosic ethanol plant that generates demand for pulpwood.
There’s even a 25,000-acre poplar plantation operated nearby by a company called Greenwood Resources that has been a pioneer in plant genetics for fast-growing poplar.
“We’ll run a silage chopper through it (the poplar plantation) and send it to ZeaChem, and they will make all kinds of chemicals out of it — not just ethanol,” Licht said.
Licht believes the green waste water treatment approach could become the salvation of many small Iowa towns that face costs to replace existing waste water treatment plants that will drive their citizens’ utility bills to high levels.
In towns near a wind farm, the trees could be planted in the “footprint” of the wind turbine, which cannot be developed for other uses, Licht said. Pulp could be harvested periodically to supply a local pulpwood or ethanol industry, and the process could generate carbon credits that the towns could sell to defray their municipal expenses.
The budding interest in the technology stems not from the green revolution but from the weak economy that has generated interest in leaner government.
“Nobody wants more taxes,” Licht said. “What they want is a way that will let them accomplish the same thing cheaper.”
But Licht expects a bumpy road to regulatory acceptance.
“When you try to fundamentally change something this big, you’re going to gore a lot of oxes,” he said. “The current rules are written for a lot of other technologies.”
Even so, Ecolotree has never been busier. Licht said the company, which usually operates with a small work force of part-time administrative staff and seasonal field employees, may even hire its first full-time employees next year.
“The world is watching,” said Licht, who has spoken to industry and government officials from several countries in Europe and Asia about his findings.
In Iowa, Licht can envision the same type of tree-based waste water system being used to provide tertiary waste water treatment — the final stage of purification — in many small communities. Land within the “footprint” of wind turbines would make a good location for the fast-growing forests, he said, because they cannot be developed for other uses.
“It has a potential create a brand new commodity — poplar and willow woods that could be harvested and used for manufacturing different products,” he said.
Greenwood’s big poplar plantation near Port Morrow, Ore., harvests wood for lumber that is exported to Japan to rebuild tsunami-damaged structures, Licht said. It is also used in wood chips for paper pulp, in addition to the cellulosic ethanol.
Licht sees phytoremediation research as an emerging area, much like the science of growing corn in the 1920s. He said major public companies are interested.
“You wouldn’t fight for a sewage treatment plant if you could do this,” he said.