1. Altitude and configuration of the potentiometric surfaces of the upper and lower aquifer systems in Bridgeton, Nockamixon, and Tinicum townships, Bucks County, Pennsylvania, April 1991 through April 1992 Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Lemoyne, Pennsylvania : U.S. Department of the Interior, U.S. Geological Survey, 1993 Resource Type: Map Access & Availability: Loading