C.3.2   Site Investigation

This former golf course will become a residential development. While it was an active golf course, arsenic was applied in two ways. MSMA was used as an herbicide to stunt the growth of unwanted plant life, mostly on the fairways. Also, arsenic-rich fertilizer was used frequently on the course. Fertilizer was used more heavily on the tee boxes and greens than on the fairways. The contaminant of concern (COC) is arsenic and soils are the media of concern. Preliminary characterization showed that arsenic is the only COC, and that it ranges from about 0 to nearly 100 mg/kg in some areas, with significant contamination limited to the top 6 inches of soil.

Beyond characterization and collection of data suitable for human health risk assessment, investigation of this site was also used as a field demonstration of various theories relating to ISM; therefore, several alternative sampling designs (incremental and discrete) were implemented concurrently, allowing comparison of their efficacy.

Three-quarter-acre DUs were identified for investigation as representative exposure units for a human health risk assessment. In each DU, both discrete and ISM samples were collected. DU 1 was an area where previous remediation had been conducted, and the soils were expected to be quite homogeneous in regards to arsenic contamination. DU 2 and DU 3 were selected based on an expectation that they might have more elevated levels of arsenic. Similar approaches were taken for DUs 2 and 3, so in the interest of brevity, only results from DU 1 and DU 2 will be presented herein.