It is no wonder that Jack Gordon used to think of kiln dust as a "growing, spreading gray monster." His cement company churned out 150,000 tons of the waste each year. Two million tons already filled nearby gulleys. A local landfill was almost overflowing. "It was clear we were building a stockpile that would go beyond reasonable capacity," says Gordon, former president of Atlantic Cement Co., in Stamford, Conn.

Atlantic learned how to tame the monster, and transform it into a growing side business. Kiln dust, which is mostly limestone and potassium, helps farmers neutralize acidic soil.

Farmers are hardly an obvious market for the expansion of a cement company's business. But Atlantic reorganized to exploit a profitable opportunity, unlike many big companies that pass up promising new ventures that lie on the periphery of their main business.

For Atlantic, which was recently acquired by Blue Circle Inc., the first step involved redefining its self-image. Some veteran employees argued that the company should stick to the business it knew best -- cement. "One thing about being CEO is you can overcome these things by telling people you are going to do it," says Gordon. "We hammered them a little bit." Eventually, a "unanimity of purpose" grew among employees.

Gordon didn't analyze the opportunity alone. John Dagneau, a longtime employee, managed a new business unit that focused on kiln dust and potential markets. "Once they recognized it as a separate venture, they could see that it was a genuine business opportunity right under their noses," says William Parker, of The New Directions Group Inc., consultants that worked with Atlantic.

The company had made halfhearted attempts to sell kiln dust before. Farmers in their trucks would line up for hours, growing impatient as they waited for a load. Dagneau spent months talking with the farmers, learning, for instance, that kiln dust couldn't be spread using a conventional rotary spreader -- a light breeze would send it onto the neighbor's soil.

His talks with limestone suppliers yielded a solution that made the venture even more profitable. Dagneau hired many independent contractors to whom he leases spreading equipment. They deliver and spread the kiln dust, which is now called NewLime. Parker says that Atlantic grosses an average of $16 a ton -- with a better return on investment than cement.

Of Atlantic's $125 million in revenues last year, about $750,000 came from NewLime. Dagneau wants to expand to such markets as garden shops, and is even looking into franchising.