The St John's Mine is a mineral extraction site approximately three miles north of the city of Vallejo in

Solano County Solano County () is a county located in the U.S. state of California. As of the 2020 census, its population was 453,491. The county seat is Fairfield. Solano County comprises the Vallejo–Fairfield metropolitan statistical area, which is a ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. The St John's site was used for extraction of

cinnabar Cinnabar (; ), or cinnabarite (), also known as ''mercurblende'' is the bright scarlet to brick-red form of Mercury sulfide, mercury(II) sulfide (HgS). It is the most common source ore for refining mercury (element), elemental mercury and is t ...

in the early 1900s. The St. John's Mine is classified as a medium priority mine from the standpoint of environmental oversight.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 In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material ...

; however the tailings exceed 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 Hastings ( ) is a seaside town and Borough status in the United Kingdom, borough in East Sussex on the south coast of England, east of Lewes and south east of London. The town gives its name to the Battle of Hastings, which took place to th ...

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.

References

Former mines in California History of Solano County, California Buildings and structures in Solano County, California Geography of Solano County, California {{US-mine-stub

Environmental effects

See also

References