St. John's Mine

The St John's Mine is a mineral extraction site approximately three miles north of the city of Vallejo, Solano County, California. The St John's site was used for extraction of cinnabar in the early 1900s. [ [http://www.admmr.state.az.us/DigitalLibrary/USBM_IC/USBMIC8252MercuryPart1of2.pdf U.S.Bureau of Mines, "Mercury Potential in the United States"] ] The St. John's Mine is classified as a medium priority mine from the standpoint of environmental oversight. [ [http://www.cleanestuary.org/publications/files/Task4.05-InactiveMinesImpl.pdf Oversight of inactive mercury mines in California] ] The last inspection of the Hastings Mine occurred in 1997 and found only slight erosion of the considerable mine tailings; however the tailings exceed convert|10000|cuyd|m3 of material, or one of the largest cinnabar tailings in the State of California; furthermore, the drainage from St. John's Mine flows to receiving waters of Rindler Creek and thence to Lake Chabot. Miles of underground shafts were driven in the course of working the quicksilver deposits in the area. In 1989, Earth Metrics reviewed old 1918 maps of workings of the Hastings and St. John's Mines and found that mine shafts were not driven into the site prior to the year 1918.C.Michael Hogan, Marc Papineau et al., "Environmental Assessment of the Columbus Parkway Widening between Ascot Parkway and the Northgate Development, Vallejo", Earth Metrics Inc. Report 7853, California State Clearinghouse, Sept, 1989]

Environmental effects

Principal ongoing impact is from mercury contamination of spring water flowing beneath the site; moreover, historical analysis has shown that the volume of spring water itself has been greatly reduced from levels of a century ago. This reduction of spring flow has come about due to the extensive mine shafts driven to achieve the cinnabar extraction.C.Michael Hogan, Marc Papineau et al., "Environmental Assessment of the columbus Parkway Widening between Ascot Parkway and the Northgate Development, Vallejo", Earth Metrics Inc. Report 7853, California State Clearinghouse, Sept, 1989]

ee also

*Hayward Fault
*Hastings Mine

References

External links