The Hastings Mine is a mineral extraction site approximately 4.5 miles (7.2 km) northeast of the city of Vallejo

Vallejo, California

Vallejo is the largest city in Solano County, California, United States. The population was 115,942 at the 2010 census. It is located in the San Francisco Bay Area on the northeastern shore of San Pablo Bay...

, Solano County, California

Solano County, California

Solano County is a county located in Bay-Delta region of the U.S. state of California, about halfway between San Francisco and Sacramento and is one of the nine San Francisco Bay Area counties. The county's population was reported by the U.S. Census to be 413,344 in 2010...

. The Hastings site on Sulfur Springs Mountain

Sulfur Springs Mountain

Sulfur Springs Mountain is a mountain in southwestern Solano County, California. The slopes can be accessed via hiking trails emanating from Blue Rock Springs Park in the city of Vallejo. Cinnabar deposits were extracted from this location in the early 1900s at Hastings Mine and St. John's Mine...

 was used for extraction of cinnabar

Cinnabar

Cinnabar or cinnabarite , is the common ore of mercury.-Word origin:The name comes from κινναβαρι , a Greek word most likely applied by Theophrastus to several distinct substances...

 until the year 1930. The Hastings Mine is classified as a medium priority mine from the standpoint of environmental oversight. In the last inspection of the Hastings Mine in 1997, sediments in a drainage below the mine were found to contain ten parts per million of mercury

Mercury (element)

Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

; furthermore, spring water below the mine exhibited a water concentration of .31 micrograms per liter (a violation of the State of California standard for receiving waters of .05 micrograms per liter). Miles of underground shafts were driven in the course of working the quicksilver

Mercury (element)

Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

 deposits in the area. In 1989, Earth Metrics reviewed old 1918 maps of workings of the Hastings and St. John's Mine

St. John's Mine

The St John's Mine is a mineral extraction site approximately three miles north of the city of Vallejo in Solano County, California, United States. The St John's site was used for extraction of cinnabar in the early 1900s. The St. John's Mine is classified as a medium priority mine from the...

s and found that mine shafts were not driven into the site prior to the year 1918.

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.