Environment & Science
12:20 pm
Wed May 29, 2013

Human waste as farming fertilizer? Detroit may become top producer of dried 'biosolids'

Detroit has budgeted $683 million to move forward with plans to build a biosolids dryer facility in the city. If built, it is expected to be the largest facility of its kind in the United States.

What exactly is a "biosolids dryer facility," you ask?

It converts human waste materials into energy or fertilizer.

Whether you view this as innovative green technology or just plain gross, the contract is a big deal for Detroit. 

According to Christine Ferretti of The Detroit News, the Detroit City Council voted 6-2 earlier this month on a contract for the construction and operation of such a facility with the Maschusetts-based New England Fertilizer Company (NEFCO). (You can view the full contract here.)

But Detroit’s emergency manager Kevyn Orr holds all the power and he has not given his opinion on the proposed project -- or the future of the Detroit Water and Sewerage Department, for that matter.

Ferretti explains the significance of the project:

Historically on an average day, Detroit has incinerated 70 percent of its solids and trucked the remaining 30 percent to landfills or to farms for land application.

Under the new plan, the city will dry nearly 70 percent of the sludge, incinerate about 17 percent and the remaining amount will be sent to landfills or to farms for land application.

While this might be seen as a great solution to deal with sludge (the material leftover from sewage treatment processes), others are concerned about its environmental impact.

The facility would be located across the street from the wastewater treatment plant on Jefferson in Southwest Detroit.

According to Khalil AlHajal at MLive, Council member Ken Cockrel, Jr. has this to say:

"I think this does raise some questions about air quality and quality of life in Southwest Detroit."

The biosolids industry and the EPA maintain that the practice of recycling human waste back into the earth is safe when treated and processed correctly.

Green technology that may harm human health?

However, one study by public health specialists found that sludge-based fertilizer might be causing illnesses in humans.

Amy Lowman was the main author of a study by the Gillings School of Global Public Health. She found that more than half the people living next to the fields sprayed with sludge-based fertilizer reported symptoms including burning eyes, nausea, vomiting and diarrhea.

"Study participants told us that onset of the symptoms occurred while the sludge was being applied or soon after. These were not one-time incidents, either. Respondents reported these illnesses occurring several times, and always after the biosolids were applied to nearby farmland."

Saginaw’s sewage treatment plant already delivers biosolids to farmers across Great Lakes region that is used to fertilize crops, as Gus Burns reported for MLive in 2011.

According to Burn' report, the use of human waste as fertilizer has been met with mixed reviews by the public - especially for those living next to farms that spray it. 

- Julia Field, Michigan Radio Newsroom