source: Jepson Prairie Organics
Callooh callay, oh frabjous day! San Francisco has just become the first American municipality to institute city-wide compulsory collection of food scraps, which get composted. Nationwide, the EPA reports that food scraps make up an appalling 13% of the refuse currently sent to landfills. Once there, they decay anaerobically (without oxygen), a process that produces methane, a greenhouse gas which is twenty times more potent than carbon dioxide.*
One of the best things about SF's policy, it seems to me, is that the city has done all it can to make it easy. It delivers its "green carts," available in three sizes, to residents, and the service costs them nothing, though businesses do have to pay.
Furthermore, when these folks say "food scraps," they mean it. Meat ("including bones,") and fish ("including shellfish") can be tossed into the carts. No messing about trying to separate the leftover meats from the vegetables; just scrape the scraps into the bin. Food-soiled paper and cardboards — ice-cream cartons, pizza boxes, paper plates and so on — can also be tossed in the green carts. (The SF web-site lists all allowed and dis-allowed items.)
All that stuff banned from your back-yard compost pile can go into a large-scale composting system because its sheer size guarantees that it will reach the high temperatures (over 130F, or 54.4C) necessary to kill pathogens. (Guarantees, that is, as long as it's efficiently managed.)
The compost is being sold to local farmers, including vineyards, which prefer it to other, yardwaste-only products, because compost made with food scraps does a better job of improving soil structure. Do those sales cover the cost of the program? Apparently the private company that runs it thinks so.
Ironically, even San Francisco — with the best program in the States — lags way behind many cities in Asia, where food waste is often fed to livestock, and in Europe, where composting has been in place for years, or even in North America. Toronto's composting policy encompasses numerous items that terrify Americans, even those in San Francisco: baby diapers, sanitary products, pet bedding, kitty litter, and dog feces, to name a few.
I wonder when we'll catch up? Before the ice-caps melt, drowning most coastal cities, driving their inhabitants inland, and making organized efforts impossible, I hope.