11.8 Bingham-Magna Ditch Site, Salt Lake Valley, Utah (2008)
Contact: Scott Everett
Organization: Utah Department of Environmental Quality
Email: [email protected]
11.8.1 Site Description and Conceptual Site Model
The Bingham-Magna Ditch (BMD) is a gravity feed ditch that once conveyed excess tail water from copper precipitation plants located in Bingham Canyon (Bingham Mining District). The BMD was located on property deeded, by easements, to the Utah Copper Company. The BMD was historically approximately 12 to 15 feet wide and approximately 17 miles long (Copperton, UT to Magna, UT). The ditch was constructed around 1932 and used until about 1935, when excess waters were sent to the South Jordan Evaporation Ponds. By 1937 the land on which the BMD was located was deeded back to the original property owners when Utah Copper Company relinquished the easements it held. Utah Copper Company was the predecessor to Kennecott Utah Copper Company, which is now known as Rio Tinto Kennecott Copper (RTKC).
In the early 1900s, the process to recover copper at various precipitation launderers in Bingham Canyon resulted in high concentrations of dissolved iron in the resulting tail water waste streams. Arsenic, which is naturally found in the ores mined in Bingham Canyon, has an affinity to bind to iron. During the process to precipitate copper from leach water, arsenic would transfer into solution (following the iron) and be conveyed in the resulting tail water to the BMD. As the tail water flowed along the ditch, the sediments that precipitated from the solution contained an iron-arsenic compound which was simultaneously deposited along the bottom of the BMD.
184.108.40.206 Arsenic on the Site
220.127.116.11 Soil Type
18.104.22.168 Source of Arsenic
22.214.171.124 Land Use/ Exposure Scenarios/Soil Management Strategies
11.8.2 Methodology Used for Evaluating Bioavailability
126.96.36.199 In Vitro Analysis
11.8.3 Calculated Bioavailability of Arsenic in Soils
11.8.4 Application of Bioavailability to Risk Assessment
11.8.5 How Did Bioavailability Results Affect Site Decisions?