On June 9, the San Francisco Board of Supervisors approved a new law that requires every residence and business in the City to have three, separate color-coded bins for waste: blue for recycling; green for compost; and black for trash.

The ordinance takes effect this fall. Under the new law, households or businesses that fail to properly sort their refuse could face warnings and fines of $100-$500. The ordinance calls for garbage collectors to leave tags on containers when they spot incorrectly sorted material.

The City hopes that the new requirement will prove effective in cutting down on the 618,000 tons of organic waste that was deposited in landfills in 2007. Organic waste in a landfill is not exposed to oxygen. Anaerobic decomposition generates methane gas, which is 25 more potent in trapping heat than carbon dioxide leading to global warming. According to a 2008 report by the Institute for Local Self-Reliance, cutting organic waste sent to landfills would be like closing 21 percent of U.S. coal-fired power plants.

Perhaps the new law will help people better learn where to put their refuse. It’s not really that difficult. Green — food scraps, plant clippings, biodegradable food service products (like those available at Green Event Shop.com), milk cartons, etc. Blue — cans, bottles, cardboard and many plastic containers. Black — Styrofoam, plastic food service products, and other non-organic waste.

Green bin contents are reused locally to nourish local farms and gardens. Blue bin contents are mostly sent to foreign countries to be reused in lieu of raw materials. Black bin contents go to nearby landfills where they stay for hundreds and hundreds of years.