According to the United States Environmental Protection Agency (EPA), generation of municipal solid waste in this country, in 2008, was 249.6 million tons. That's the equivalent of about 4.5 pounds of waste per person per day. 12.7 percent of that was food, the third-largest waste stream, after paper and yard waste. That's something on the order of 32 million tons of food waste, of which less than 3 percent, or 1 million tons, was recycled. The other 31 million tons ended up in landfills or incinerators.
A 2004 study, conducted by the University of Arizona, Tucson, Bureau of Applied Research in Anthropology, found that American household waste, on average, resulted from 14 percent of their food purchases. Fifteen percent of that includes products still within their expiration date and/or never opened. In other words, an average American family of four throws away about $600 in purchased food annually.
2008 EPA information also indicates that yard waste (grass, leaves, tree and brush trimmings) accounts for 13.2 percent of the municipal solid waste in this country, slightly more than food. In fact, according to EPA, organic materials - yard trimmings, food waste, wood waste, paper and paperboard products - encompass the largest component of our trash and make up more than two-thirds of this nation's solid waste stream.
The price for that is the growing problem of how to handle all the waste that is generated. Even if America's cities weren't running out of valuable, irreplaceable land, which they are, landfills would still be far from an ideal disposal solution.
Landfills are large and expensive to build and operate, and there is little decomposition of trash in most landfills, especially once they are capped. What's more, they emit air and water pollutants. Again according to EPA, landfills are the single greatest source of methane gas emissions in the United States. Methane is a potent greenhouse gas, which contributes to global warming and climate change.
The good news is that methane can be captured and used to generate power. And, although it's not a renewable resource, landfill gas in solid waste management systems could potentially supply a very small percentage of the nation's energy. In fact, the city of Vancouver, British Columbia, Canada, operates a landfill in the district municipality of Delta, on the U.S.-Canadian border, which uses landfill gas to provide both electricity and heat. The electricity is sold to BC Hydro and the heat is used to warm greenhouses that grow vegetables year-round. But that's another story.
For the most part, disposal of food waste and yard trimmings in landfills is not necessary. We can, individually, dramatically reduce the amount of food and yard waste that we generate, keeping it out of the solid waste stream, thereby saving landfill space and reducing methane production in landfills by composting. And we can save money by avoiding disposal fees.
Compost is decayed organic matter that can be used to improve soil structure, add nutrients and promote healthy soil microorganisms. Composting is one of the easiest and cheapest ways to provide healthy, nutrient rich organic matter for your garden soil. Very little time or equipment is required. Before you start composting, however, you need to at least become familiar with the composting process and how it works.
The easiest way to compost is to just pile yard trimmings and food waste on the ground or in a bin and wait. This is referred to as slow or cold composting and it works well if you produce a minimal amount of waste, don't have time to tend to your compost pile, or don't need the compost until say 2011 or 2012.
Hot composting is a bit more complicated. But with the right ingredients and a little effort, you can turn a good size pile of household, workplace or agricultural waste (for the best results, a pile at least 4-by-4-by-4-feet is necessary) into compost in just a few weeks, weather permitting, often from early spring on into the fall.
Decomposing organisms need four key elements to thrive: nitrogen, carbon, moisture, and oxygen. Green organic materials (grass clippings, food scraps, livestock manure), contain large amounts of nitrogen. Brown organic materials (dry leaves, wood chips, twigs and woody debris) contain large amounts of carbon. You need to find a suitable balance of these materials, usually about a one to one ratio, to properly manage rapid decomposition.
Turning the pile regularly, every few days; moving materials from the center to the outside and vice versa, provides oxygen. You can add bulking agents, such as wood chips and shredded newspaper also, to help with aeration. Too much oxygen, however, can cause the pile to dry out, inhibiting the decomposition process.
Microorganisms need adequate moisture to survive. Organic materials contain some moisture but additional moisture is often necessary and can be provided by exposing the pile to rain or by watering, keeping in mind that you want your pile to be moist, not soggy.
Obtaining a proper balance of materials, moisture and oxygen takes practice, time and patience. A little experimentation will be necessary and is part of the science of composting. When everything is working as it should, the pile's core will remain heated to somewhere between 110 and 160 degrees Fahrenheit, supporting microbial activity and promoting quick, effective breakdown, as well as eradication of weed seeds and pathogens.
Some organic materials are just not appropriate for composting. Avoid putting meat scraps, bones, dairy products, pet feces, grease, fatty foods or diseased plant material into your compost pile. Use of these materials may slow the composting process down, result in unpleasant odors and/or attract unwelcome animals or insect pests.
One last thought. Ash from your woodstove, fireplace or campfire pit can drastically alter the pH of soil. For this reason, it should be used sparingly in gardens and never added to compost.