Los Angeles County is known for having the stinkiest sludge in America. Virginia Tech environmental engineer John Novak says the sludge from that county in California has the "worst odor of any I have ever tested."

"This county can haul its sludge hundreds of miles into the desert, and it still gets complaints," Novak said, according to a press release by Newswise.

His laboratory on the Virginia Tech campus tests sludge from water and wastewater treatment plants.

Novak said that any time a treatment plant processes water or wastewater it generates sludge. His lab receives shipments of processed solids from sewage twice a week.

If "a package stinks, it belongs to me," Novak said.

"Biosolids management is one of the most important aspects of wastewater treatment because of economic and health and safety issues," Novak said. "The cost of biosolid treatment and hauling is a major expenditure for wastewater treatment utilities. Pathogens and odor problems may restrict the biosolid disposal options and affect hauling costs."

In addition, the nitrogen content of biosolids applied to land as fertilizer can degrade groundwater quality. Novak advocates a dual-processing method to digest wastewater solids that uses both aerobic and anaerobic processes to treat wastewater. That method reduces volatile waste more than either process alone, Novak said.