The monograph is a collection of published papers on underground corrosion of steel piling. The papers describe corrosion of various types of steel piling exposed underground in the United States under climatic conditions ranging from semi-tropical to frigid. Corrosion is described on driven piling above and below the water table after many years of exposure in soils having resistivities between 78 and 50,000 ohm-cm and ranging in pH from 2.3 to 8.8. One of the papers demonstrates the value of a polarization technique in measuring corrosion. Polarization data were obtained on weighed steel pipe specimens exposed underground for seven years in backfilled soil trenches in the vicinity of driven sheet piling. The technique was evaluated by comparing calculated cumulative weight losses of specimens with their actual weight losses. The technique was also shown to be applicable to underground pipe piling. (Author).