Manufactured Gas Plants
Former Napa Manufactured Gas Plant

PG&E, under the oversight of the California Department of Toxic Substances Control (DTSC), is conducting a voluntary program related to a historic manufactured gas plant (MGP) that operated on portions of the property formerly occupied by the Riverside Apartments at 201, 211, 221, 241, 251 and 267 Riverside Drive in Napa.
The Napa MGP was built in 1888-1889 by Napa City Gas Light & Heat Company. PG&E acquired and operated the gas plant from 1905 until 1924, when it was closed and then dismantled. PG&E sold the vacant property in 1961, several years before the apartment complex was built.
In the 1980s, working under the oversight of the appropriate State and Federal Environmental Protection Agencies, PG&E performed testing at this location to look for residues from historical gas plant operations. We shared all data with the property owner at the time, agencies and regulators. No further work was requested because the data collected indicated that the site did not pose a health concern.
In January 2010, PG&E purchased the property in order to investigate and, if necessary, clean up the site. This investigation process involves collecting samples of soil, soil vapor and groundwater at the Riverside Apartments property and soil samples at the nearby riverbank. In order to safely conduct work at the site, the apartment complex was closed in August 2010. PG&E assisted tenants with finding permanent replacement housing.
The apartment buildings were taken down and the site was cleared in summer 2011. Additional soil and groundwater sampling is currently taking place. PG&E will work with DTSC to review the sampling results and determine next steps.
The surrounding community is kept informed of progress at this site through work notices, fact sheets, and other outreach as appropriate.
Additional Resources:
- Work Update - May 2011 (PDF, 203 KB)
- Program Update - Winter 2011 (PDF, 879 KB)
- Program Update - Summer 2010 (PDF, 586 KB)
- Fact Sheet – February 2010 (PDF, 271 KB)
- DTSC Resources & Contact Information



