Date

2002

Document Type

Capstone Project

Degree Name

Bachelor of Science (B.S.)

Department

Science & Environmental Policy

Abstract

Trichloroethylene (TCE) is a volatile organic compound the U.S. Army used extensively on the former Fort Ord prior to the post's closure. TCE is a probable human carcinogen and can cause a range of health effects depending on the quantity and duration of exposure. Fort Ord operated a group of landfills located on the post. The Army used these landfills for disposal of TCE-containing waste, and TCE subsequently leached into and contaminated the A-, 180-foot (Upper), and 180-foot restricted (Lower) aquifers. My project goals were to compile relevant information on the landfill and trichloroethylene, determine where the areas of highest TCE contamination exist in the aquifers of concern, provide an easy-to-read graphical representation of how the TCE plume has changed over time in the aquifers of concern, and ascertain if the current remediation strategy is appropriate for these aquifers. Using quarterly monitoring well data provided by the United States Army Corps of Engineers, I produced layers of annual TCE concentration gradients for each of the three aquifers using a geographic information system (GIS). I imported these images into an animation program and produced digital movies of the change in TCE concentration per year in each aquifer. Using these images, I determined that there is small but significant evidence of TCE plume flow. The areas of current highest TCE concentration include: pockets of relatively high concentration north and northwest of landfill Cell A and to the north and northeast of Cell F in the A-aquifer; areas of relatively high concentration located north, northwest, and southwest of Cell A of the 180-foot (Upper) aquifer; and an area of relatively high TCE concentration northwest of Cell A in the 180-foot restricted (Lower) aquifer. The Army's current remediation strategy for this site includes a pump-and-treat system. I concluded this is the most appropriate methodology given the unique properties of the site and the current technology available. However, I also feel it will be necessary in the future to re-evaluate the feasibility of the Army's goal to reduce TCE concentrations to EPA drinking water standards.

Comments

Capstone Project (B.S.) Earth Systems Science & Policy Institute

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