IOWA CITY, Iowa (AP) - Jennifer Jordan walks up to a 250-foot mound of compost on a sunny morning at the Iowa City Landfill and Recycling Center.
She spears it with a thermometer and smiles as the gauge soars to 160 degrees Fahrenheit, almost 70 notches above the outdoor temperature.
"Is that not so cool?" marvels Jordan, the city's resource management superintendent. "That's the process. That's Mother Nature."
The pile is made up of food scraps, like eggshells and banana peels, and yard waste, like dead wood and mown grass. But it doesn't stink. Even in the winter, the sped-up process of natural decomposition generates enough heat to convert what was once Johnson County residents' leftovers into rich soil.
But the city is running out of space to turn the 11,500 tons of yard and food waste it collects every year into soil.