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The middle-aged and elderly with osteoarthritis and young women with depression constitute vulnerable groups who are not in a position to demand services. The older women particularly need assistance as they are bearing the double burden of their own degenerative conditions and the results of the HIV/AIDS pandemic.

A wood-treating facility, located near Sheridan, Oregon, has been the focus of a groundwater contamination investigation. A geophysical survey was conducted in April, 2000. Objectives of this geophysical survey included detection and delineation of coarse-grained channel-type deposits in the unconsolidated section above bedrock. These deposits constitute preferential pathways for groundwater flow, and hence contaminant migration through the subsurface. Contaminants consist of petroleumbased creosote and pentachlorophenol (PCP) solutions. Dissolved phases of these contaminants comprise the groundwater contamination expected, and the delineation of the extent of this contamination was the overall objective of the investigation. In addition, dense non-aqueous phase liquid (DNAPL) contamination was expected in accumulations in topographic lows of the bedrock surface near the source area. Therefore, another objective of the geophysical survey was to investigate any topography on the bedrock surface. In this preliminary phase of the investigation, geophysical methods used consisted of transient electromagnetic (TEM) soundings, a resistivity sounding, and an extensive terrain conductivity (EM-31) survey. Due to the extensive sources of cultural interference at the site (buildings, fences, railroad tracks, etc.), the geophysical survey was limited. Three profiles of 20-m central-loop TEM soundings were obtained, along with some isolated soundings where it was thought that cultural interference could be avoided. TEM approximate depth sections clearly identify the paleochannel system in cross-section. Correlation with terrain conductivity response provides confidence in the terrain conductivity interpretation of the paleochannel system in areas where only that type of data were obtained. One resistivity sounding, and an adjacent TEM sounding, were modeled simultaneously to the same layeredearth in order to test the idea of improving the resolution of the interpretation. This proved valuable in delineating an electrical equivalent of the working model of the hydrogeological section based on nearby drilling information.