Municipal Composting

Just wrote this article for New Entry as well. It's about composting in a city like Boston.

Ever wondered what happens to all the food you don’t eat out at a restaurant or what you throw out from home? Chances are the wasted food goes to one of the many municipal landfills. Once in the landfill, the food slowly anaerobically decays, creating methane, and trapping all the nutrients and resources used to grow that food in a wasteful abyss. Organic waste is the second largest component of our landfills and landfills are the largest emitter of methane, a potent greenhouse gas. (Check out http://www.boston.com/bostonglobe/magazine/articles/2010/03/21/the_case_for_mandatory_composting/ for an interesting article about Boston municipal composting).

And all the food that American’s waste adds up. 30% of the food grown in this country is wasted, and 75% of that food is wasted in restaurants, homes, or the retail sector (over 50% in homes and municipal sector). So how can you play a part in decreasing this waste, making sure nutrients stay inside a usable cycle? The first thing, of course, is to work on not wasting as much food. Only take the amount of food on your plate that you will eat, and save the rest as leftovers. Try not to buy more food than you will eat just for it to go bad in the refrigerator.

But nobody’s perfect. We’re all going to have food waste whether we’re trying to decrease it or not. But composting can help us keep our natural resources out of the landfills, ensuring more sustainable nutrient cycles and making sure the food decays aerobically (producing carbon dioxide and water, two much more benign green house gases than methane). In addition, to you folks that garden or have nice house plants, you will be producing your own garden amendments to improve your plants health and soil.

However, composting can be challenging when we live in urban areas. Many of us don't have a yard, our yard may be small, or we may have neighbors who worry about the odor and possible four-legged creature infestation. Lucky for humans, we’re a very innovating bunch and people have come up with many creative ideas in order to compost in their small backyards or even inside. (Check out the MA Department of Environmental Protection's website on composting to learn more about the basics of good composting http://www.mass.gov/dep/recycle/reduce/compgnt.htm).

The easiest way to compost if you don't have a yard is to vermicompost. With this method, you adopt red wiggler worms as pets and feed them your leftover food waste. They eat it and poop out soil. All you need is a plastic storage bin, newspaper clippings, and some worms. Sommerville sells starter worm kits for $25. Other resources can be found at (http://www.urbanhomesteadersleague.org/blog/wp-content/uploads/2010/06/UHL-broadside-1.pdf). A major drawback to this method is that the worms are slightly picky eaters and you can't compost all your organic waste.

Another way to compost in very little space is to get a barrel composter or compost tumbler. Though expensive, these mechanical compost turners are very easy to use and don't take up that much space. Once you buy it (or build it if you've got construction savvy), you simply keep adding your organic waste with a mixture of some sort of brown material (such as leaf clippings) and turn the handle in order to aerate and mix the compost.

You can also use a modified garbage can structure for composting in the city. If you build it yourself, use a hammer and nails to punch holes in the bottom, sides, and lid of the garbage can. Compost turning tools are available at hardware stores that work very well for turning the organic waste inside the barrel. These barrels may also be available through your municipality for discounted prices. They also come with the guarantee of being "rodent proof." See the MA DEP for details (http://www.mass.gov/dep/recycle/reduce/compgnt.htm).

A more traditional way to compost is to have a three bin system (http://ceplacer.ucdavis.edu/files/350.PDF). An important aspect of composting is keeping a good temperature to ensure proper microbial decay. Though this is influenced by a number of factors such as the carbon to nitrogen ratio, the moisture content, and the aeration, it is also important that your compost pile be at least a cubic yard for good heat build up. However, as a single family (or even single person) in the city, it is unlikely that you'll produce this much organic waste. To get around this problem of thermal mass, you can build just one cubic yard bin and divide it into 4 partitions. You can treat it similarly to a three-bin system's rotation, but you'll use less space and need to add less organic material for a healthy pile.

As you can see, there are many solutions for composting even when we live close to our neighbors in the city. We can all play our part to reduce green house gases, landfill size, and keep nutrients in a usable cycle.

I didn't actually answer the basics of a good compost pile in this article (ie good C:N ratio, good aeration, good moisture, good temperature, etc) so for more information I highly recommend The Rodale Book of Composting.