11 Case Studies
The case studies describe how bioavailability values have been used in decision making at specific sites. Examples include results for lead, arsenic, and PAHs in soil. These case studies illustrate the type of work that might be undertaken in site-specific bioavailability assessment or in support of a new program on bioavailability. The studies outline the site-specific analyses that were conducted to support alternative (not default) inputs for bioavailability in the human health evaluation or remedy selection for the site. In some instances, the analyses were relatively straightforward and based on in vitro extraction data for soils from the site. In other instances, the effort entailed new research or the development of new research methods.
ITRC continues to collect case studies that illustrate the use of technologies for which it publishes guidance; contact team leaders to share a case study.
The case studies presented are summarized in Table 11-1.
| Case study | Contaminants | Soil Type | Source Type | State |
|---|---|---|---|---|
| Empire Mine State Historic Park, CA | Arsenic | High Iron | Mining | California |
| Road 1815, Cattle Dip Vat Site, Ozark National Forest, AR | Arsenic | Sandy loam with gravel and cobbles | Pesticide, pre-1950 | Arkansas |
| Hill Air Force Base, UT | Arsenic | Red-stained surface soil at former groundwater seeps on a hillside | Naturally occurring arsenic mobilized by reduced groundwater conditions and historical wastes | Utah |
| Resolution Copper West Plant Site, AZ | Arsenic | Not available | Smelter | Arizona |
| Red Rock Road, Douglas County, OR | Arsenic | Well-graded gravel with some fines. High in Iron oxides | Mining of mercury ore | Oregon |
| Confidential Site, Midwest, U.S. | Lead | Not available | Industrial | Midwest, U.S. |
| Former Foster Air Force Base, Victoria, TX | PAH | Clay, silt, sand with localized gravel and caliche | Skeet target fragments | Texas |
| Bingham-Magna Ditch, Salt Lake Valley, UT | Arsenic | Arsenic occurs predominantly in association with iron oxyhydroxides | Tailings water from copper precipitation plants, copper ore | Utah |
| Over the Horizon Backscatter (OTHB) Receiver site, CA | Arsenic | Red soils, high in iron oxides | CCA wood preservative | California |
| Former MGP site, MI | Arsenic | Fill, fine to medium grained sand | MGP coal ash | Michigan |
| Barker, Hughesville Mining District, MT | Lead | Not available | Mining | Montana |
| Silver Bow Creek/Butte Area Superfund Site, Butte, MT | Lead | Alluvial deposits, sandy clay to sand and gravel | Mining | Montana |
| Midvale Slag NPL Site, Midvale UT | Lead | Soil and slag | Former smelter | Utah |
