Description:
The historic lode mines in the Randsburg District include the Yellow Aster, Baltic and Olympus Mines, which were actively mined for lode gold mainly during the 1890's -1942 period. The historic Yellow Aster 100-ton Mill was constructed during the early 1900's and was replaced in the 1910's - 1920's with a large-scale cyanidation mill processing circuits. Roughly $25 Million dollars of gold bullion was produced by the mine during its 50-year mine life, at 1920's gold prices. Approximately 500,000 tons of mill tailings and 500,000 tons of waste rock were generated by milling and mining operations, respectively. The Randsburg lode mill tailings and waste rock has been discovered recently to contain highly elevated levels of arsenic (5,000-13,000 ppm). These tailings have discharged from tailing dams and ponds and rock dumps over the last + 100-year period into residential areas within the town site of Randsburg and thence into Fiddler Gulch and Fremont Valley Wash and then into the Koehn Lake Basin and floodplain areas.
The Yellow Aster lode mine and other significant lode gold properties were remined during the 1980's and 1990's time period and were designated as the Rand Mine project. Glamis Gold Corp.is the current owner/operator. Historic mine tailing have been disturbed by this recent mining operation and continue to discharge offsite onto BLM-managed lands and into the waters of the State.
Significant potential human health risks to the community and regional environmental impacts may have resulted from release of arsenic-bearing tailings into the waters of the state and airborne sources. This area has now been designated as an AML CERCLA site. Sample results from water, sediment, and biota indicate elevated arsenic and mercury level exist in the floodplain sediments. A CERCLA time-critical remediation process has been implemented.
A RSI (Removal Site Investigation) document will be compiled during FY2006-7. Compilation of a focused EE/CA (Engineering Evaluation/Cost Analysis) document will be contracted during 2007-8. Remediation options will be listed in the EE/CA. Identification and coordination of identified Responsible Parties (RP) will be required to effectively remediate and stop continued migration of arsenic tailings downstream onto residences and downstream watershed areas.
Benefits:
Proposed improvement of human health by reduction of dermal and airborne exposure to arsenic by undertaking proposed remediation of arsenic-bearing mill and mine tailings. The Removal of arsenic-mercury contaminated sediments within active stream channel/100-year floodplain will change its present status as a pollution "nonpoint source" under the Clean Water act and prevent continued downstream discharge into the Fiddler Gulch, Fremont Valley Wash, Koehn Lake Basin watershed. The California State Water Control Board and other regulatory agencies require that BLM mandate significant reductions in arsenic loads from its managed lands within California.
Feasibility:
This site is one of BLM's high priority AML 1010 sites for CERCLA cleanup actions. During FY06-7, technical specialists will collect water and sediment samples. During FY06-7 BLM specialists and BLM contractors will finish compilation of the required CERCLA environmental documents. During FY06-10 BLM specialists and BLM contractors will undertake emergency remediation or removal actions of the arsenic-bearing tailings. During FY11-12 BLM specialists and BLM contractors will undertake post-remediation monitoring actions.
Support:
There is widespread support from interagency Federal partners (USFWS, EPA), State Partners (DOC AMLU/OMR, DTSC, CWQCB, RWQCB, CA Fish&Game, CA Dept. Public Health), County Partners (Dept. Envtl Health) and various regional stakeholders.
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