KANSAS CITY, Mo. (AP) - A Kansas City farm that uses sewer sludge to fertilize crops for the production of biofuel has generated revenue for the city while providing a way to get rid of tons of sewage produced each year, city officials said.
The city uses the waste as fertilizer on 1,340 acres it owns along the Missouri River near a wastewater treatment plant. The farm grows mostly corn and soybeans that are sold to make biofuel - meaning none of the crops are meant for human consumption, The Kansas City Star reported Monday (http://bit.ly/XayLE3 ).
The program has brought in $2.1 million in profit since the city took over farming on the land in 2006.
"That is fantastic," said Tammy Zborel, who works with a sustainability program for the National League of Cities. "That is not a common practice for cities to engage in that level of farming."
The city used to burn its waste in incinerators, an expensive process that requires lots of water, gas and electricity, said Kurt Bordewick, manager of the Water Services' wastewater treatment division.
In the mid-1970s, the city bought 300 acres of Missouri River bottomland and dug two lagoons to store waste from the Birmingham wastewater plant. Every two years, the lagoons were cleaned and some of the waste was applied to the ground.
In the 1980s, the city bought digesters to remove the water from the waste, creating biosolids, which tenant farmers used on crops grown for the city. An elaborate system of pipes was built underground to distribute the fertilizer. The city was producing more biosolids than the farm could handle, Bordewick said, so it kept buying more ground in anticipation of continued growth in population and waste.
The city took over most of the farming in 2006 after Timothy Walters, an agronomist and farm manager for the water department, decided the land could produce more and better crops.
"We do all the tillage, and we plant the crops," Walters said. "We don't do the harvest because we can't afford a $300,000 combine."
The water department conducts extensive testing and monitoring to ensure the biosolids do not contain harmful contaminants.
The effort has paid off, both in increased revenue and reducing the amount of waste that the city needs to burn.
From 2000 to 2005, average yearly gross from the land was $52,373. From 2006 to 2011, after the city took over farming, average yearly gross was $455,451.
And 2007 was the last year when more biosolids were incinerated at the Birmingham plant than were used as fertilizer. Last year, 9,982 tons of fertilizer were spread on the farm, and 2,044 tons were incinerated.
"It's my goal to get out of the incinerator business," Bordewick said.