The California Department of Toxic Substances is preparing for an environmental cleanup project in Colusa that is scheduled to take place this summer. 

According to a release issued by the department, the former PG&E Colusa manufactured gas plant, located at 105 Second St., produced gas for lighting, cooking and heating needs for local residents from 1886 to about 1940.

The plant was dismantled in 1942 and now operates as a PG&E Service Center and electrical substation. 

As part of a volunteer project overseen by the DTSC, PG&E has conducted several investigations of soil and groundwater at the site to determine the extent of remediation necessary to address residues left over from the historic operation of the gas plant, according to the PG&E website.

“In 2013, PG&E completed cleanup work at the site,” read the PG&E website. “Over the course of five months nearly 3,700 cubic yards of soil was excavated from areas that contained old gas plant residues. Excavated areas were backfilled with clean fill material and the site was restored to its original condition.”

Site restoration has also included landscaping using drought-tolerant native plants near the planter areas on First, Second and Market streets. According to their website, PG&E worked with the Colusa Garden Club to develop a landscaping plan for the exterior areas of the site and the Garden Club continues to maintain these areas under a partnership that is the first of its kind in California between a public entity and a private garden club.

According to their website, PG&E considers sustainable practices to be an important part of the restoration process as they try to reduce their carbon footprint on environmental remediation projects as much as possible. 

“During this work we recycled a total of 960 tons of material,” read the PG&E website. “This project also contributed $619,900 to the local economy, which included hiring five local laborers.”

During the next phase of the environmental cleanup project, PG&E plans to replace electrical equipment at a portion of the substation by de-energizing and removing existing equipment.

“This provides PG&E an opportunity to remove previously inaccessible contamination on the eastern side of the site,” read a release issued by DTSC. “DTSC is currently reviewing a draft Explanation of Significant Differences to the 2011 RAP that proposes additional environmental work to include the excavation and off-site disposal of soil contaminated with polycyclic aromatic hydrocarbons, total petroleum hydrocarbons, polychlorinated biphenyls and metals.” 

Once the review is completed, a DTSC will release a community update to provide information on the findings of the Explanation of Significant Differences report and a 30-day comment period will open.

Additional information about the project can be found at

For more information, contact Karri Peters, project manager for the Department of Toxic Substances Control, at 916-255-3614 or email

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