Description
Abandoned mines are common throughout California with recent estimates exceeding 50,000. During the 1920?s the Black Mountain Open Space Preserve, San Diego, California was home to a short-lived mining operation for Arsenic which was processed for use in pesticides. On-site mine activities were limited to one specific canyon near the northeast perimeter of the Preserve. These activities resulted in the generation of several hundred tons of waste rock and processed ore material. Much of this material accumulated in the canyon and is a potential human and ecologic exposure concern. Current regulations dealing with abandoned mine sites require an estimate of the volume and concentrations of waste rock and ore material in order to complete an appropriate Site Characterization. Volume estimates of mine waste rock were determined by surveying the inside of each of the 4 mines using lasers and standard survey techniques. This data will be compared to an in situ seismic survey of the canyon to obtain an estimate of the volume of waste rock and processed ore materials remaining in the canyon. These data will be used to formulate remediation and engineering techniques, if required, to reduce the potential exposure of the Arsenic bearing material. In the future, these techniques may be applied to Site Characterization of additional abandoned mine sites throughout California.
Site Characterization and Geophysical estimate of Waste Rock and Tailings, Black Mountain Open Space Preserve, San Diego, California
Abandoned mines are common throughout California with recent estimates exceeding 50,000. During the 1920?s the Black Mountain Open Space Preserve, San Diego, California was home to a short-lived mining operation for Arsenic which was processed for use in pesticides. On-site mine activities were limited to one specific canyon near the northeast perimeter of the Preserve. These activities resulted in the generation of several hundred tons of waste rock and processed ore material. Much of this material accumulated in the canyon and is a potential human and ecologic exposure concern. Current regulations dealing with abandoned mine sites require an estimate of the volume and concentrations of waste rock and ore material in order to complete an appropriate Site Characterization. Volume estimates of mine waste rock were determined by surveying the inside of each of the 4 mines using lasers and standard survey techniques. This data will be compared to an in situ seismic survey of the canyon to obtain an estimate of the volume of waste rock and processed ore materials remaining in the canyon. These data will be used to formulate remediation and engineering techniques, if required, to reduce the potential exposure of the Arsenic bearing material. In the future, these techniques may be applied to Site Characterization of additional abandoned mine sites throughout California.