You are a responsible environmental citizen. You turn your thermostat up in summer and down in winter, and if your server offers a plastic straw, you politely decline. When Columbia resumed curbside recycling, you wanted to declare a citywide holiday. Still, you can’t shake the feeling you could be doing something more for Mother Earth — and you’re right. That something is residential composting. 


According to the U.S. Environmental Protection Agency, food makes up 24 percent of the country’s...