A multimedia contaminant fate, transport, and exposure model (MMSOILS) was developed by EPA for the human exposure and health risk assessment associated with release of contaminant from hazardous waste sites. The model addresses the transport of a chemical in groundwater, surface water, soil erosion, atmosphere, and accumulation in the food chain. An application of the MMSOILS has been conducted at a hyrocarbon contaminated site in a federal facility. Transport modules for non-aqueous phase liquid (NAPL) and gas phase was hardwired in the original model to handle the transport processes of spilled and leaked hydrocarbon in forms of NAPL and gas through unsaturated soil zone. The site was contaminated with JP-4 leaked from underground pipeline in front of the fire station in the Coast Guard air field. At the site, At the site, natural attenuation with long-term monitoring was adopted as the aletrnative contaminant management after two years of active remediation. the multimedia model was applied to assess the health risk to the base personnel during the life-span of the remaining contamination.