Friday, December 16, 2005

A Note on Composting

Many environmentalists, including those who oppose disposer usage, point to composting as a preferable alternative for handling food waste. However, after speaking with solid waste management experts the consensus is that while this method is useful to some degree it is not an optimal solution, especially for large urban areas.

As environmental engineers like Professor Carol Diggelman point out (Diggelman co-authored with Dr. Ham the previously mentioned disposer study), composting is an energy intensive process that requires a lot of open land and an untainted supply. Obviously New York City does not have sufficient open space so the result is that the food waste must be trucked great distances. As environmentalists know, but for some reason ignore in this case, this trucking emits considerable pollution and is costly. It is a bit mind-boggling that these advocates would want to maintain or even increase the number of waste pickups in NYC’s neighborhoods.

But what about once the food waste gets to the composting site? According to Diggelman, as well as the waste operations people in Philadelphia, once food waste is added to a compost heap it must be a) free of any contaminants and b) heavily contained. If there is anything but food waste added to the pile the end product is severely compromised and not very valuable. In fact, Dr. Ham said that for first world nations, composting as an all-encompassing solution has been a failure because the end product is usually not worth a whole lot.

The containment issue is also very important. Compost heaps are basically organic landfills and emit the same malodorous greenhouse gases. Once additonal food waste is added to the pile these side effects are exacerbated and therefore the piles must be sealed to prevent the release of fumes and the seeping of contaminants into the ground. Also, the conversion of methane and other emitted gasses to energy is much harder at compost facilities and Professors Diggelman and Ham have proven that this recycling process is much more efficient with food waste disposers.

However, composting does have its place, these experts say. After food waste is processed at a treatment plant and converted into sludge that material is then composted or used as soil enrichment. By putting the food waste down the drain, you eliminate many of the above-mentioned negative aspects of composting and the end product is actually of a much higher quality.

The general consensus is that composting – at least the way certain environmentalists see it – is not a solid waste solution and may actually make certain environmental problems worse (not to mention increase hauling costs). People need to be realistic and realize New York City has a garbage crisis, one that won’t be solved by utopian visions. In fact, Mayor Bloomberg said it best when asked about the viability of food waste composting:

I believe that in lower density areas of the City, food waste and yard waste composting should be encouraged on a voluntary basis. In the higher density areas, the threat of vermin and a lack of storage may make composting impractical. There are alternatives. The use of food waste disposal systems has now been legalized in the City. Improvements in design of these systems minimizes the impact upon our sewer system. As long as waste treatment facilities can assure that our harbor and bay waters are not endangered by use of garbage grinders, their use should be encouraged. Efforts by private charities such as City Harvest, in cooperation with area schools, institutions and restaurants, further minimizes waste and helps those in need by delivering excess food to distribution points for those who need it.