It's a byproduct of Petaluma?s new $115 million wastewater treatment plant, which will process up to 2 billion gallons of the city?s raw sewage each year, converting about a quarter of it to recycled water for parks and crop irrigation.
It also produces about 20 tons a day of sludge ? known in the industry as bio-solids ? which get trucked to area landfills and are available as fertilizer.
?This is beautiful,? said Orr, the plant?s engineering manager, as she held the loamy material to the sunlight. ?You can put it on a farm field and it augments the soil.?
After nearly four years of construction, the Ellis Creek Water Recycling plant opened this summer without major complications, officials said.
The project near Lakeville Highway was completed on time and with a 4.4 percent cost overrun, replacing the 70-year-old facility on Hopper Street that had fallen into disrepair.