"When I take people out here in the winter, sometimes we just lie down on it," says Susan Thoman. She's gesturing to a mound of rich black organic matter the length and height of a warehouse at the Cedar Grove composting plant, a sprawling complex an hour north of Seattle. Sealed under Gore-Tex fabric and "blimped" with fans, the giant piles reach a toasty internal temperature of 130 degrees thanks to beneficial bacteria. They steam in the foggy air, which is scented miraculously with bark mulch, not rot, like the floor of the thicket for which the place is named.READ»