Risk Narrative
The Blue Hole Pit Lake is located on unpatented BLM administered land but adjoins other large patented hydraulic and drift placer gold mines in the Sailor Flat Mining District. The +20 acre blocked drain tunnel mine site contains a sluice box tunnel of unknown length driven in slate bedrock . The tunnel iutlet has been blocked by forming a pit lake. The perennial pond is used as a swimming and recreation site by neighborhood residents. Initial water, sediment and biota samples have been collected to assess total and methyl mercury contamination values during the 2000-2001 period.. Recreationalists have complained that their skin itches after contact with the water. Water samples results indicate that the pit lake water contains a low PH and skin irritations are common symptoms of bathing or swimming in acidic water.
Reclamation/Recommendations
1. Pit Pond - Acidic Water Contamination
Acidic water occurs in the hydraulic mine pit lake that is being used as a recreational bathing and swimming site by the public. Acidic water conditions occur as a result of historic hydraulic mining impacts. Seasonal sample results indicate that acidic water conditions persist throughout the year.
2. Public Access and Use: Access to the site is currently unrestricted. The site is primarily accessed used by recreationalists.
3. Land Status and PRP Search :
A potential responsible party (PRP) search will be initiatied in FY 2002 for those historically responsible for hydraulic mining related impacts. The potential exists for a cooperative AML partnership between BLM staff and adjacent landowners. Estimated cost $10,000.
4. Site Investigations - Sluice tunnel outlet has not yet been discovered. Field work needs to focus on identification of the tunnel outlet area and to assess whether acidic water discharge is aiding methyl mercury generation downstream. Estimated cost $15,000.
5. Restoration Methods Being Considered:
a. Chemical Restoration - Pit Lake - (Neutral PH Waters)
It is possible that neutral water conditions can be temporarily restablished at the pit lake, using buffering agents, such as adding crushed limestone materials into the lake.
Estimated cost $20,000.
Risk: Hg Contamination
AMLIS #: CA021800048
Location: N39 19 34, W121 09 2
Field Office: Folsom
Congressional District: 02
