Brown and Caldwell was retained in April 1983 by the attorneys for a major metal finisher located in East Los Angeles to investigate the potential contamination of property. A determination was to be made of the extent of contamination and recommendations were to be provided for cleanup measures. The impetus for this site contamination investigation was a citation by the Los Angeles County Department of Health Services for industrial discharges along and adjacent to a railroad right-of-way. The focus of this paper is on the technical and engineering aspects regarding the steps taken in the course of conducting a contaminated site investigation and cleanup. Although this particular study involves heavy metals as the principal contaminants, the general procedures outlined in this paper are applicable to any other type of contamination. This case study will merely be used to illustrate the components of a contaminated site investigation and cleanup.