Americans have a separation problem, and nobody knows that better than municipal composters.
When ordinary trash is thrown into green curbside collection carts, companies spend time and money to remove it and cart it to the landfill.
"I had the accounting department look at the average over the last nine months, and we pulled (from incoming green waste) 68 tons per month of contamination, primarily plastic," said Greg Pryor, general manager of Vacaville's Jepson Prairie Organics, which composts San Francisco's green waste.
Municipal green waste is the name given to plant material collected from yards, city parks and commercial landscaping. In a few cities, including Oakland and San Francisco, it includes food scraps from produce handlers and residential, restaurant and hotel kitchens. Composting green waste reduces the amount of garbage entering landfills and cycles nutrients back to gardens, parks and farms.
Compost can include animal manures, sawdust and sewage sludge, none of it likely trash-free. But municipal green waste is probably the trashiest material to enter the compost stream.
Balls, batteries, electrical wire, irrigation tubing, watering cans and garden tools find their way in; even a bicycle has been found with the green waste at Jepson Prairie. "It's broken, it's in my yard, must be yard waste," seems sometimes to be the attitude. Then there is the full lineup of plastic bags: grocery bags, trash bags, fertilizer bags and, coming full circle, compost bags.