Manufactured Gas Plants
Former St. Helena Manufactured Gas Plant
A manufactured gas plant (MGP) was formerly located at 1301 Mitchell Drive in St. Helena. PG&E has completed investigation of the site and work is ongoing to clean up soil and groundwater affected by historical operations. All work for this voluntary program is being conducted under the oversight of the California Department of Toxic Substances Control (DTSC) and the Regional Water Quality Control Board.
Following investigation, PG&E removed soils from portions of the site and the adjacent property in 2007. A treatment system was installed that same year to remove MGP residues from soil and groundwater underneath other areas of the site. In January 2011, PG&E expanded the system to remediate another portion of the site. This expansion included the installation of additional equipment and wells. PG&E will be conducting additional investigation in 2012 in preparation for the next phase of soil removal at the site.
The St. Helena MGP operated from 1883 to 1930. PG&E acquired the property in 1930 and used it as an electrical substation until 1989. Today the site is vacant except for the onsite remediation system.
Site-related documents can also be found at:
St. Helena Public Library – Reference Desk, 1492 Library Lane, St. Helena (707-963-5244)