China, formerly the world's largest buyer of recyclable paper and plastics, no longer imports recycled materials. Global recycling facilities now demand improved sorting practices and reject bales of materials containing greater than one percent impurities. In the face of these realities, some U.S. cities have pulled back from recycling. San Francisco, however, is meeting the challenge head on and continues to lead North America in the recovery of recyclable materials. Recycle Central, the 200,000-square-foot materials recovery facility operated by Recology, is the backbone of San Francisco's recycling system, according to Recology.