A Different Kind of Factory

Whiting-Turner Contracting Co. has nearly completed a $19.5 million recycling facility in Elk Grove that will transform tens of thousands of gallons of wastewater into 20 tons of fertilizer daily.

By Thomas York

	PHOTO BY GREG ARAGON

Officials of the Sacramento Regional County Sanitation District say they've found a way to reduce the flow of sludge from the local wastewater plant.

In 2003, agency officials signed a 20-year contract with Houston-based Synagro Technologies Inc. to design, build and operate a biosolids facility to turn thousands of gallons of wastewater sludge into dry fertilizer pellets. Synagro, in turn, signed agreements with Arlington, Texas-based Andritz-Ruthner Inc. to supply the processing equipment. The Sacramento office of Black & Veatch designed the plant and Baltimore-based Whiting Turner Contracting Inc. is the general contractor.

Construction of the Biosolids Recycling Facility began in August 2003. It is being built at the sanitation district's Elk Grove wastewater treatment facilities.

When it is completed in October, the 14,000-sq.-ft. facility will transform tens of thousands of gallons of wastewater sludge into 20 tons of biosolids daily, said Ruben Robles, biosolids program manager for the sanitation district. The plant will produce a minimum of 7,500 tons of fertilizer pellets a year, which Synagro will market to customers worldwide.

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Robles said the plant cost $19.5 million.

The biosolids facility is the first plant to be built by Synagro in California, said Paul Santos, Synagro's project manager for the Elk Grove facility. He added that a similar facility is being built in Honolulu, and that Synagro has built and operates plants in Florida, Maryland, New York and Pennsylvania. Santos said commercial fruit and vegetable growers in Florida are his company's main clientele.

Pam Racey, Synagro's vice president of business development, said huge centrifuges draw off the moisture content in the sludge over several cycles. Dryers then reduce the remaining sludge to pellet-size pieces, which can be used on commercial and residential lawns and gardens.

"It's quite an operation, but it's an effective way of dealing with wastewater sludge," Racey added.

Robles said the processing equipment has been placed within a custom-designed, contained building to reduce noise and odors. He said the building is double-walled, which helps to greatly reduce noise from the processing equipment, especially the dryers.

The facility also will treat air emissions to further reduce odors connected to wastewater sludge processing.

Bruce Corwin, Black & Veatch's project manager, said the plant was designed and constructed with the concerns of neighbors in mind.

"It has architectural features to make it match the surrounding treatment facilities," he added. "Everything's hidden inside, and you wouldn't know what's going on inside unless someone told you."

He said that he expects sanitation agencies in other parts of California to build similar plants given the concern about increasing amounts of wastewater sludge being dumped into the environment.

"There are not that many places to dump sludge anymore, so anybody in this business will be looking to build plants, too," Corwin said. "We're certainly going to see more of these facilities."