By Jackie White
Turning unwanted food scraps into nutrient-rich, natural fertilizer instead of sending them to a landfill -- sounds great, right? But if you're new to the composting process, it may seem daunting to have yet another thing to sort from your trash. Or you may lack the space to compost at home. Luckily, Seattleites have a system for curbside compost pick-up. Here's a look at why composting is important, how to use Seattle's system, what happens to all that waste, and tips for getting started.
Why composting is important
Composting and recycling significantly reduce solid waste volumes. Since 1989, Cedar Grove Composting (a private, for-profit company that handles city, county, and commercial compost) has accepted more than 2 million tons of waste that would have been sent to landfills. The composting process converts unwanted waste into a useful product.
We're already on the right track: Seattle set a city record in 2006 by sending 47.5 percent of waste to recycling instead of to landfills. And as of March 2008, more than 100,000 households were participating in the city's yard and food waste program. But we're missing a lot: estimates show that half of our remaining solid waste could still be composted or recycled. Mayor Nickels set a city goal of diverting 60 percent of Seattle solid waste from landfills by 2012. Zero waste programs around the world set the bar even higher, with goals of 90 percent and above. As we've discussed on Worldchanging before, designing waste out of the process from the beginning is the most important step we can take. But programs like composting, recycling, reuse and product stewardship all help shrink the waste stream coming out of Seattle.
How to use Seattle's composting system
Those with a yard or garden can easily compost at home. But for those without the space or time to do so, the City of Seattle contracts with Cedar Grove to process residential yard and food waste with bin service, provided to residents for $5.35/month. Many Seattleites have used the yard waste service, which began in 1989, for many years. But it wasn't until 2005 that food scraps became acceptable additions to the compost bin.
Along with plant material, food waste and food-soiled paper can be placed in the bin for collection.
Things to compost include:
meatless food scraps
eggshells
grains
coffee filters
tea bags
pizza boxes
paper towels
non-coated paper cups and plates
Don't compost:
meat
dairy
grease
plastics or plastic-coated paper products
Currently, meat and dairy are excluded as a precautionary measure, to prevent pests and health hazards related to storing the waste. But the Seattle City Council recently approved, as part of their Zero Waste Strategy, a weekly pickup plan that will allow residential customers to compost meat and dairy, starting in April 2009.
With all the hype around biodegradable, corn-based plastics in recent years, you may be wondering where these items fall on the compost list. Because they biodegrade at varying rates and temperatures and affect the final compost product in different ways, these items are not currently accepted in residential yard waste bins. Some specific brands are accepted from commercial compost clients, who have a broader overall range of acceptable materials than residents, and Cedar Grove officials say they are constantly testing new products for compost-ability.
What happens to the waste?
City staffers deliver residential compostable material to the Cedar Grove plant north of Everett (Cedar Grove staff manages the collection for commercial operations). After initially collecting in the tipping room (where truckloads are unloaded), materials travel along a conveyor belt, where metal and plastics are removed. The waste is then formed into piles and covered.
Cedar Grove uses GoreTM Cover Membrane Laminate Technology, a system of specialized covers, and regularly monitors temperature and moisture in the compost heaps. The high heat achieved in Cedar Grove's large-scale processing kills any weeds and pathogens, and also meets the standards for organic certification. After the two-stage heat aging process (approximately 21 and 30-45 days respectively), bagged compost is aged for an additional 18 months to ensure quality. Bulk compost is aged 6 to 12 months.
Finally, the bags of organic compost are delivered to stores around Seattle, where residents can purchase the natural fertilizer for use in their own yards. For homeowners, landscapers, gardeners, organizations like Seattle Tilth, and others, this would-be waste has become a wonderful resource!
Tips for getting started
* If you don't already have a yard waste bin, order one from Seattle Public Utilities (1 year commitment, $5.35 per month). Renters can request bins from their landlord.
* Begin by adding large items to your yard waste bin - i.e. grass clippings, pumpkins, pizza boxes, etc.
* Save your food scraps for the compost! You can place scraps in a paper or a compostable kitchen bag that can go right in your yard waste bin. Some people like to collect scraps in a container in the freezer, to avoid any unpleasant odors. Reusable containers with lids are another good bet.
* Look for compostable options when you shop. If you must use disposable servingware for a party, choose non-coated paper plates and cups. And seek out restaurants and other venues that use compostable packaging for prepared foods.
Jackie White is the Environmental Steward for Seattle Art Museum, based at the Olympic Sculpture Park.
Photo credit: Flickr/arimoore, licensed by Creative Commons.
