Site Characterization and Remediation

Suppose that your manufacturing facility asked you, its Environmental & Safety Manager, to conduct a remedial investigation of soil and groundwater contamination located at a warehouse and manufacturing facility it purchased, as is, from another corporation. Your corporation is responsible for any environmental cleanup from existing contamination, if any, because it did not perform an environmental site assessment prior to purchase. Such industrial real estate transactions are not uncommon when the selling price is attractive to the purchaser. During a preliminary assessment of the site after the purchase, significant subsurface contamination with waste oil was discovered. Because the location of the source material (i.e., waste oil) was unknown, a waste delineation program must be conducted to determine the primary source and extent of the oil contamination. In addition, an estimate of the amount of waste oil contaminated soil to be either excavated and removed or treated in place must be established. The site has three buildings containing industrial equipment where different kinds of oils were used in previous manufacturing processes. These three buildings are presently not being used for any activity. There is also evidence of the use of a relatively large subsurface pit by the previous property owner to dispose of used oils, prior to shutting down their manufacturing operations in the building.

In addition, the facility is noted to have had an onsite petroleum fueling station to fuel up the facility’s transport vehicles. For such facilities, fueling tanker trucks fill the above-ground tanks (ASTs) storing the fuel. Accidents during these filling operations are not uncommon during the fueling operation, and there appears to be evidence of at least one release of fuel to the ground during an AST filling operation. There is a non-potable water supply well about 100 feet down gradient from the suspected fuel release location. The water from this well has historically been used for washing and other manufacturing processes in the plant.

Complete the following:

• Design a site characterization plan to establish the extent of soil impact and presence of petroleum products in the groundwater (if any). The purpose of this delineation should be to estimate the extent or spread of contamination, and the amount of impacted soil and groundwater (if any). To accomplish a thorough delineation study, consider the former manufacturing activities in the facility, where waste oils could potentially be produced, how much waste oil was produced, how it was disposed of, potential interviews with former employees and neighbors, and so forth.
• Compare and contrast at least two possible remediation options that you will propose to your employer to address the contamination. Assume that the extent and degree of the contamination is known to you from the results of the above site characterization. Further, assume that a good part of the contaminated waste oil and released petroleum products will have to be remediated to meet acceptable cleanup levels but that the groundwater meets regulatory concentrations and does not need to be remediated any further. Consider time frames for remediation that may impact the company’s ability to use the property for the intended purpose.