Water Industry News

Columbus Water Works honored for technique
that turns human waste into safe fertilizer

Feb. 22, 2005
Staff Writer

Columbus Water Works received top state engineering honors for an innovative project that transforms human waste into fertilizer.

The American Council of Engineering Companies of Georgia gave the top prize to Water Works Saturday in Atlanta for the project, Columbus Biosolids Flow-Through Thermophilic Treatment Investigation.

"Its about finding an effective and a positive way to address these solids that people in this community generate," Water Works President Billy G. Turner said. "It's the most cost-effective way for us to do it, and it will be a good way to make the solids much more useful and desirable."

The common technique used by many cities is to heat the biosolids separated from wastewater and ship some of it to farms for soil enhancement. But federal regulations prohibit the waste from being close to food crops, which limits where it can be stored. Many major cities, such as Los Angeles, send the waste to landfills more than 100 miles away at a huge cost, according to the Associated Press.

The technique Water Works, along with environmental engineering firm Brown and Caldwell of Atlanta, developed is to heat the solid waste at even higher temperatures and send it through a specialized plug to ensure all waste is properly treated. The product is then sent to area farmers as a super fertilizer, free of pathogens found in some animal manure and far safer than less-treated human waste.

"Essentially, materials from the soil are going back to the soil," Turner said.

He admitted that the subject of human waste is not something to bring up at the dinner table.

"Nobody likes to talk about this, but every day, every hour, every minute, waste is generated and it has to go somewhere," Turner said.

Gwen Brandon, assistant executive director of Georgia Engineering Alliance, said Water Works out-placed 12 other competitors and is eligible for national designation for the study at the American Council of Engineering Companies annual convention in Washington on April. 11.

Entries were judged on categories such as originality, innovative applications of new or existing techniques, future value to the engineering profession, complexity and social and economic impact, Brandon said.

"In our opinion, the study was pretty cutting edge," competition judge Bruce Moulds said.

Moulds, who is an engineer at HNTB design firm in Atlanta, said the social and economic impact of the study is what won the judges over.

"The benefits to the profession and the treatment of waste water went above and beyond the other entries," Moulds said. "It was just an opportunity to reduce the substantial operational costs that are part of these wastewater treatment programs."

About $500,000 could be saved annually in Columbus from not hauling the sewage to a landfill, Turner said. The process also cuts down on the time biosolids are treated from 24 hours to 30 minutes, which saves more than $2 million in construction costs.

A unit at the south water plant is currently using the process, and construction will be complete on additional units in two years, Turner said. In total, the project will cost $12 million. About $6 million is funded federally, the other $6 million through a state revolving loan process.

This is the second time Columbus Water Works received the designation. In 1996, the company was awarded for the construction of a new overflow system that led to the Columbus Riverwalk.