Once a Pollutant, 'Scrubber Sludge' Finds a Market. The Wall Street Journal, October 5, 1998, ppB1,B2.
Power companies that have been using "scrubbers" to remove the sulfur and fly ash coming out of their stacks are now selling this waste to farmers and construction companies instead of dumping it into landfills. Two companies, Caraustar Industries and Babb Cellular Concrete use the sulfur and fly ash to make construction products such as wallboard and concrete. Farmers are also buying the residue-called "scrubber sludge"- because it helps increase crop yields. "Wherever you put that stuff," said Ken Curtis, owner of a fertilizer business in Illinois, "it just greens up." In the past, power companies usually buried the sludge in landfills, incurring liabilities. Now the Tennessee Valley Authority makes from $6 to $10 million annually on sales of the byproduct. "We're turning a deficit into a positive number," said Cheri Miller, a TVA marketing specialist. Ralph Woodward, a farmer from Carlisle, Indiana has a farm by a power plant. Woodward thought that the scrubbing process mandated by the Clean Air Act would result in a sulfurous sludge that would probably improve the soil. He asked the officials at the plant if he could have some because they were just dumping it. "They just ignored me," said Woodward. He then donated $50,000 to Purdue University to test his theory. He persuaded soil scientist Darrell Norton to test his theory. "If this old dumb farmer makes a claim that [sludge] works, they don't pay much attention to you," Woodward says. "But if Purdue does it, that it authentic." Dr. Norton found that the sludge could increase crop yields and reduce water-pollution runoff by increasing the soil's capacity to hold rainwater. The use of the sludge on some farmland has been approved by federal and some state environmental agencies. It has been slow to sell however. "It's an education process. Farmers have never heard of it." The construction industry also was looking at ways to use the sludge containing calcium sulfate. The mineral, also known as gypsum, is the raw material used to make wallboard. Some manufacturers were mining the mineral from distant locations at great expense. A power plant near Jacksonville, Florida began selling sludge to farmers in the late 1980s. Soon after, a wallboard company bought their entire output. "If we had more, they'd probably take that too," says Jay Worley, an official at the plant. Indianapolis Power and Light Company sells about 300 tons a year from one plant. Some of their other plants are being upgraded to produce higher quality sludge. "When you are getting paid for byproduct, you can afford to spend more money on it," said Jim Meiers, the utility's chief scientist.
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