Archive for October, 2011

October 29, 2011

Rotting Piles of Garbage: How to compost the low-impact way

I’ll be the first to admit it: I love compost. I love not throwing things in the trash, I love bugs and things that eat rotting food, and I love being able to put that food back into my garden. I even love how it smells – after it’s fully composted, that is.

My thing for compost goes back to college, where I was introduced to the wonders of growing your own food through a course in urban farming. Since then, I’ve gone out of my way to keep my vegetable scraps out of the landfill.

Out of my way is putting it lightly, actually. My little fetish for decomposition has been a smelly problem, one that I never really found an easy solution to. In my apartment existence, I’ve been known to do a bit of “guerrilla composting” by tossing my food scraps into the neighbor’s bushes. Usually, I just stored them in stinky, leaky plastic bags until I remember to bring them to the farm. I’ve even started a couple mini worm farms under the kitchen sink, but never with much success.

If I happened to live in a bigger, more progressive city, my compost problems would be solved – actually, hauled away every week in a big truck. In Hartford, Hereford, and Hampshire, hurricanes hardly happen, but in Portland, Seattle, Boulder, Austin, Minneapolis, and around 3,000 other US cities, you can place your compostable kitchen scraps in your yard waste bin. In San Francisco, composting is actually mandatory. The movement is part of a larger effort to reduce the waste stream – all the consumables we send to our landfills. Landfills are designed to do the opposite of a compost heap, preventing decomposition to avoid the release of climate-altering methane gas (composting, on the other hand, is an aerobic process, which produces small amounts of less potent carbon dioxide). They’re very effective at this – a newspaper placed in a landfill will still be readable 35 years later.

Most of us tend to worry about the land-based impacts of landfills, but a more pressing concern associated with piling all our waste in a central location is the energy used and carbon dioxide produced in the process of picking up and delivering it. In my town, there are at least three major sanitation companies offering weekly pickup for trash and every-other-week pickup for yard waste and recycling. In Portland, the recently introduced yard waste/compost pickup service is offered every week, and I can’t imagine this being less frequent due to the smell factor. That means at least two trucks a week stopping by every home, and three on recycling weeks. Four if a separate truck is required for glass recycling, as it is in my neighborhood. Guess what the fuel economy is for the average diesel-fueled garbage truck. Nope, lower. Lower. Lower. Three miles per gallon. Seriously. To make matters worse, nobody wants a smelly, ugly, potentially flammable municipal compost facility near their home or farm, so trucks must sometimes travel farther to get to those locations than they do to get to landfills.

So is separating food waste from other household trash and sending it off to be composted really an idea we should get behind? Maybe if we replaced the yard waste trucks with a fleet of bicycles. Or maybe there’s another solution, one that addresses the other side of the problem – not what we’re throwing out, but what we choose to save.

In the lifetime of, say, a carrot, the part where it gets thrown away (either as a whole or as peelings and greens) is a pretty small part. It grew in soil, absorbing minerals, converting sunlight into energy and soaking up water. In a way, that carrot was like a battery, storing energy for future use by whomever ate it. It also stored some vitamins and minerals, part of which are absorbed by the eater’s digestive system. (Our habit of depositing what we’ve digested into sewer systems that don’t recycle nutrients is unfortunate in this light, but that’s another discussion.) The part of the carrot that doesn’t get eaten can go down two paths. On the landfill route, its nutrients and potential energy are locked away virtually forever. If composted, the energy goes into millions of microscopic creatures, and the nutrients are reused if that compost gets put on a new vegetable garden.

Nutrients are valuable, and although veggies are a renewable resource, the minerals that make them desirable in the first place are not. Like gold and silver, there is a limited amount of phosphorus, calcium, iodine, etc., in the thin crust around the core of molten rock that together make a planet we call home. When crops are grown in fertile soil, which has been enriched over billions of years with minerals from volcanic ash and disintegrated rock, those plants absorb the minerals and pass them along to whomever eats them.

After 10,000 years of agriculture on this planet, the store of minerals in the soil has all but been depleted. Comparing soils today with those tested just 100 years ago, there’s been an 85% loss in mineral content, a loss that is reflected in the nutritional value of the crops we grow. According to the Nutrition Security Institute, “Our food system is rapidly losing its ability to produce food with nutrient levels sufficient to maintain health.” Thirty trace minerals are essential to life, and some scientists say we need every element on earth in minute amounts for optimum health. Minerals are essential to everything from bone growth (think calcium) to DNA coding, the firing of neurons, energy transfer and metabolism, cell structure, and much more.

So maybe I was on the right track with trying to keep my vegetable scraps in my neighborhood to be recycled. Curbside compost programs, which haul nutrients away never to be seen again, don’t seem to make much sense, but composting at home does. It’s a bit like opening a savings account. When you stash your cash at the bank (provided it doesn’t fail), it can be loaned out to someone else while you’re not using it. Under the mattress, it doesn’t do anyone much good. Throwing food scraps in the landfill is a bit like putting your money in your bed. In landfills, food scraps only break down very slowly because of the lack of oxygen, and when they do, they release methane gas, which contributes to global warming. Second, like saving money in an interest-earning account, you’re actually increasing the benefit to yourself. You can spread your compost on your garden beds to increase soil fertility and grow strong plants that are resistant to disease. Third, unlike saving money, it’s fun.

Well, I think it’s fun. This summer I moved into a house with a real yard, and the first thing I did was build a fascinating – yet admittedly messy-looking – compost pile under the tree in the back yard. In just a couple feet of food scraps, mixed in with a little newspaper, it’s incredible the varieties of life that can unfold. I turned the pile every few weeks and marveled at the centipedes, grubs, worms, potato bugs and fly larvae crawling just underneath the top layer of banana peels. But Hannah, my domestic co-habitator, called it “the rotting pile of garbage”, and although she is a seasoned farmer herself, she somehow didn’t want the final stage of life for untold numbers of vegetables to unfold just off the patio.

The fall season finally provided the two of us with enough overlapping time off to do something about my DIY landfill. Our goal: Create a complete and attractive home compost system with minimum financial input. She’s a barista and I work at a non-profit – neither of us are overpaid.

To start, Hannah and I took a trip to BRING Recycling to rummage up some materials to build a tidy backyard compost bin in which to corral the creepy-crawlies and their food. BRING accepts donations of used building materials and organizes them in a huge warehouse full of old doors, pipes, wood scraps, random tiles and bricks, metal filing cabinets and desks, light fixtures, and anything else that may have a second life as an art project or functional element in someone’s house. It’s like Home Depot meets Goodwill. In the wood section, we found a whole pile of cedar panels that were perfect for the sides of our bin. We also found an old window, the front of a wooden cabinet, even hinges and screws. Total cost: $40. Price of a plastic composter for home use: $150. We win.

Step two: Bribing the neighbor with coffee beans to borrow his power drill. Done.

We assemble our materials in the backyard. We’re not expert builders, but all we need is a box without a bottom, so we go for it. The cedar panels form the back and two sides of the box. The third side will be a door to release the finished compost, and for this we use the window. It doesn’t come quite to the top of the box, which is perfect to allow air to flow over the top. We put an extra 4×4 we had laying around on the back of the box before screwing on the lid, to give the top an angle that will help the rain flow off. Oh, the lid is actually that cabinet front we found.

Homemade compost bin.

Step four: The kitchen compost receptacle. We were using a plastic bucket to catch our coffee grounds and onion peels, but that soon began smelling like civet cat vomit. Metal is the ticket when storing compost temporarily, because it doesn’t absorb or hang on to odors. The only problem was, a nice steel bucket with a vented lid and carbon filter will set you back at least 30 bucks.
Strolling the isles at Jerry’s, our local home improvement mega-store, I spotted a metal canister that looked about perfect. Removable lid, handle, large enough to fit a couple days’ worth of coffee grounds and garlic peels, and only $4. An empty paint can. Beautiful. Dirty. Rich. A little acrylic paint to personalize, and we’re set. Best of all, we found a way to keep it off our valuable kitchen counter space.

The final step: The material in our lovely new bin outside is about ¾ of the way composted. At this stage, adding new vegetable scraps to the top doesn’t make a whole lot of sense. In most composting systems, you end up with three bins: an “active” one to add to until its full, a “composting” bin that’s full and breaking down, and a “finished” bin that contains fully composted material, which you can take out and use as needed.
Although my partner in composting has proclaimed a willingness to build bins around the entire house to ensure my happiness, I’m not that into the idea. I’d rather use my tiny yard space for actually growing things. Besides, now that fall is here, I don’t anticipate having as much yard waste to deal with (fallen leaves make lovely mulch and don’t need to be composted first).

Enter the worm bin. I’m always telling people who live in apartments to build a worm bin to quickly and non-odiferously turn food scraps into compost. I haven’t actually done this myself, though. (Like I said, putting worms in a paper bag full of food scraps under the sink just doesn’t cut it.) A worm bin is basically split-level condo for worms, which can be created by stacking plastic storage bins and poking holes in the top one for air. Since all worms want to do is eat and poop, it’s perfect for them because the top floor holds food scraps and shredded newspaper, and the bottom floor holds their poop – your compost. I’m thinking this will be a good solution for my household compost. I’ll post the results as they come in, including any funny things Hannah has to say about it. In the meantime, directions are here.

Maybe composting isn’t for everyone. In this culture, there is a certain “ick” factor to overcome. For me, anything that involves recycling and improves our chances of not just surviving but thriving with 7 billion plus on one planet, is good. Now that we’re out of $100 bills to light on fire, it might be time to start cultivating a new kind of wealth. All I know is, when I die, you can just throw me on the compost pile.