If the Keystone XL project is approved and built, that number will only rise, and so will the number of spills, and the public costs of dealing with them.MAPS OF TAR SANDS PIPELINES IN THE U.S.Here is a map put together by NRDC of the existing and proposed tar sands DilBit pipelines:For a closer look at the network of existing and proposed tar sands pipelines and refineries, download this map [PDF