Towards Zero Waste: Municipal Composting
There is a growing number of homeowners and even some adventurous apartment-dwellers that compost their food scraps and yard waste. There are a lot fewer cities and towns that can claim the same. Some forward thinking locales have started offering municipal composting, with San Francisco and Seattle even going as far as mandating it.
While some may joke about the idea or find it a bit odd to start separating out food scraps from the trash, there are many compelling reasons why municipal composting makes sense. About 250 million tons of municipal solid waste are generated in the US each year. Of this, food waste and yard trimmings make up over 25%, which could be composted instead of sent to landfills.
Many people think that since food scraps and yard waste are biodegradable, it's not a big deal if they end up in landfills. But landfills are used and maintained in a way that creates an environment within it that is almost free of oxygen. So organic materials that would normally breakdown harmlessly, instead decompose in that anaerobic environment in a way that generates methane. Methane is 20x more potent of a greenhouse gas than CO2, which means that the seemingly harmless food and yard waste is causing some serious damage.
Environmental benefits aside, there are cost savings for municipalities as well. With landfill space at a premium in most areas, tipping fees continue to edge upwards at an average rate of $1.24 per ton per year. The town of Amherst, NY, was able to quantify a net public benefit of $22.8 million between 1991-2008 through it's municipal composting program. Even after factoring in the cost of building and operating the composting facility, the avoided landfill fees and the revenue from selling the finished compost allowed the town to save significant money. Additionally, by sending less waste to the landfill, the useful life of it has been extended.
Municipal composting, while providing a cost savings and reducing greenhouse gas emissions, also turns something that has historically been considered a waste into a useful product. Many soils have been depleted to the point that they require added nutrients to be productive. Usually these nutrients take the form of chemical fertilizers. Adding compost is a benign way to add these nutrients back into the soil, while also creating a better quality soil that can hold more water, has more beneficial microorganisms, and has a structure that is better able to support root growth.