About 40 years ago, bedrock and dirt were excavated to build the World Trade Center in Lower Manhattan. That soil established the foundation for a 92-acre swath of land where the mixed-use neighborhood of Battery Park City was built. Landfill reuse is a fitting beginning for a planned community that today has become one of the greenest in America, due to stringent environmental guidelines developed in 1999 and implemented by the Battery Park City Authority (BPCA). It is appropriate that the most eco-friendly branch of the 89 public libraries of the New York system would be built here. While the residents in this surprisingly leafy neighborhood have their share of parks, offices, restaurants, and water views, they sorely needed a library.