People in Brooklyn will be leaving out their food and yard waste separately for compost collection beginning in October. New York City is not the first city to make it obligatory, but it’s the biggest to do so in the US so far. Mandatory curbside composting has existed in Queens since the spring, and will roll out to New York’s 3.5 million residences and 8.3 million New Yorkers borough by borough. Residents can use a bin of their choice to fill with their food scraps and yard waste which city sanitation workers will collect with trash and recycling. New Yorkers produce 24 million pounds of trash a day, a third of which is compostable. Most ends up in landfills, where it emits heat-trapping methane. Collected scraps will be sent to a composting facility to be turned into soil or converted into biogas, to heat homes. The curbside initiative will co-exist with smart composting bins around the city, which are emptied daily.