Abstract
Chevron Bulk Terminal No. 61324760, located within the Rio Grande Inner Valley in southwest Albuquerque, New Mexico, is underlain by a shallow perched aquifer which has been contaminated with petroleum hydrocarbons. The primary objective of this study was to model groundwater flow in the shallow aquifer in order to determine if the site was affected by multiple contaminant plumes, and if so, the possible source of each plume. Groundwater flow within the shallow aquifer was simulated using a two-dimensional areal model which included the Chevron terminal and the surrounding area. Three steady-state simulations assuming different flow conditions were conducted. Flow path analyses and velocity vector plots were then used to determine potential migration paths of contaminants released in the vicinity of the Chevron property. Transient flow modeling tests, designed to investigate the effects of seasonal recharge from a nearby irrigation ditch, the San Jose Lateral, were conducted with various recharge rates for the ditch. In all of the simulations, a deeper channel in the base of the aquifer directly east of the Chevron property created a converging flow pattern which prevented flow between the northern and southern sections of the property. Additionally, a north/south trending groundwater divide which passes beneath the western edge of the Chevron property produced a flow pattern which prevented movement of contaminants from the east or west toward the Chevron property. This suggests that contamination beneath the northern part of the Chevron property must have originated from on-site releases or from releases north of the property. Likewise, contamination beneath the southern part of the Chevron property must have originated from on-site releases or from releases south of the property. A statistical analysis of groundwater chemical data using cluster analysis was conducted in an attempt to verify the existence of multiple contaminant plumes as suggested by the flow model results. The existence of more than one contaminant plume was supported by cluster analysis results which revealed two identifiable groups of wells in the vicinity of the Chevron property.
Fryar, Dennis Gene (1997). Hydrogeologic investigation of petrochemical contamination at a bulk storage facility. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1997 -THESIS -F79.