Fayetteville sewer plant to sell fertilizer

To Fayetteville city officials, the approximately 3,000 tons of “biosolids” produced at the wastewater treatment facility has the smell of money.

“I’d describe it as pretty earthy, actually,” said David Jurgens, director of the city’s Utilities Department.

“Where we dry the biosolids, there’s a lot of different elements involved,” Jurgens said. “Sometimes you’ll catch a whiff, but but we have pretty extensive control measures in place.”

Biosolids are a byproduct of the city’s wastewater treatment process, which uses microorganisms including bacteria, fungi and protozoa to break down waste. The biosolids are rich in nutrients, and rich in potential as fertilizer in the state’s agricultural areas.

The facility, about 3 miles east of Fayetteville near the White River, was one of the final additions to the city’s decade-long, $180 million effort to modernize its wastewater treatment operations, Jurgens said. Using a combination of six greenhouselike structures and a 3, 000-gallonthermal dryer the size of a small bus, the city converts about 22,000 tons of wet biosolids into about 3,000 tons of dried fertilizer each year, which is then sold to the public at auction twice a year.

“Overall, it’s a really cool thing,” Jurgens said. “We took something that, four years ago, we were sending to a landfill. Now we’re making money from it.”

Jurgens said that until about 2003, the city spread the biosolids as fertilizer on about 670 acres outside the city, growing hay crops such as fescue. Eventually, however, the soil became saturated with nitrogen, and the city had to resort to taking the biosolid waste to landfills.

“We didn’t like it,” Jurgenssaid. “It was expensive, and we were landfilling a valuable product.”

Duyen Tran, project manager for the city’s two treatment plants and the biosolids drying facility, said the cost of transporting and dumping the organic waste became steadily more expensive. Landfill “tipping fees” - the fee charged by landfills for accepting waste - rose from an average of about $7.25 per ton in 2004 to about $40 per ton in 2011 for organic waste.

“We began discussing different options,” Tran said. “We wanted a sustainable solution that cost less, was environmentally friendly, and kept the city more incontrol of its own destiny when it came to biosolid disposal. In the past, we were dependant on the landfills.”

The city’s use of a twostage process, first using solar heat to reduce the overall mass of the organic waste, and the thermal heater to complete the process, was not only the first in the country, it remains the only such process in action throughout the country, Tran said.

Jurgens said the entire project cost about $8 million to construct. Operation and maintenance of the facility, along with the wastewater treatment facilities, is contracted out to CH2M Hill, a Colorado-based engineering firm.

Beginning in March, the city began auctioning off the nutrient-rich fertilizer. Thecity holds two bid days each year - the second bid-day will be Tuesday - in which bids are taken by phone, beginning at 8 a.m., “first come, first served,” as Jurgens put it.

“We’re not trying to get into the business of storing fertilizer, so our prices are pretty good,” Jurgens said.

Tran will deliver a presentation today at the Paul A. Noland Wastewater Treatment Plant in Fayetteville at 11:30 a.m. as part of the Arkansas Department of Environmental Quality’s “Putting Green to Work” luncheon series. The series is design to expose area business leaders to environmentally friendly business practices being put into use throughout Arkansas.