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Frequently Asked Questions

Former Potrero Power Plant | Site Overview | Cleanup Areas & Recent Activities | FAQ | Archive

Where is the Former Potrero MGP Remediation Site?

The Site is located in San Francisco's Central Waterfront area at 1201 Illinois Street. It is approximately 34 acres in size and is bordered by 23rd Street to the south, Illinois Street to the west, the Pier 70 site to the north, and San Francisco Bay to the east.

What is the site's history?

The site and adjacent area have been used for industrial activities since the mid-1800s. Some of the historic uses on and near the site included ship building and repair, foundries, sugar refining, and barrel making. PG&E and its predecessors operated a manufactured gas plant (MGP) in the northeastern portion of the site from the 1870s to the 1930s. A power plant, commonly referred to as the Potrero Power Plant, was built in the 1910s and upgraded and expanded in the 1960s, with the construction of Unit 3. PG&E sold the power plant property to Southern Company (subsequently, Mirant and now GenOn Potrero LLC) in 1999, while retaining portions of the site for such uses as an electrical switchyard and storage. The plant was shut down in March 2011 following the completion of the Trans Bay Cable project, which allowed power generated in Pittsburg to be transferred across the Bay to San Francisco. While PG&E no longer owns the Potrero Power Plant, we will take responsibility for the impact of our former operations.

What is a manufactured gas plant?

In the mid 1800s and early 1900s, before natural gas was available as an energy source, more than 1,500 manufactured gas plants (MGPs) were located in cities and towns across the country. These plants used coal and oil to produce gas for lighting, heating and cooking. With the arrival of natural gas in the 1930s, most of the manufactured gas plant sites in California were no longer needed and were closed.

What are the environmental impacts at the site?

The site has a long history of industrial use and has environmental impacts associated with this industrial past. The primary impacts at the site are associated with leftover MGP residues. MGPs produced a variety of byproducts, some of which were useful and marketable, such as coal tar and lampblack. The byproducts that could not be sold were removed for disposal or remained at the MGP site. Residue found at some MGP sites is comprised of various chemicals, including polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs).

Heavy metals have also been detected in site soil, along with naturally occurring asbestos, both of which can be associated with fill material or the serpentinite bedrock located beneath the site and surrounding area. Petroleum hydrocarbons have been found in soil and groundwater.

What is the status of the remediation of the property?

To expedite the remediation process, we designated seven separate work areas at the site. This allows us to investigate and remediate each area independently, and not delay work toward redevelopment in some areas, while conducting necessary work or studies in some other areas. We have made significant progress on the environmental investigation and remediation of the site. In 2012, we finished remediation work in two of the seven project areas-the Hoe Down Yard, and the Switchyard and Construction Yard Area. Remediation work in another large area of the site, called Station A is on track to be completed in 2013. This will leave work in only four remaining areas: the Northeast Upland Area, the Sediments Area, the Tank Farm and the Power Generation facility. Visit the Cleanup Areas & Recent Activities for an area-by-area overview of recent activities across the site.

After the remediation and cleanup of the site is complete, what will the site be used for? How will future uses of the site be incorporated into the City’s plan to redevelop this area of San Francisco and the adjacent Pier 70 property?

The areas of the site owned by PG&E, such as the Switchyard and Hoe Down Yard will continue to operate as PG&E facilities. The former Power Plant area of the site is owned by GenOn Potrero, LLC who will decide its final disposition.

Who owns the former Potrero Power Plant property?

PG&E sold the Potrero Power Plant property in April 1999 to Southern Company (subsequently, Mirant Corp. and now GenOn Potrero LLC). Other areas near the power plant property, such as the Switchyard and General Construction Yard and Hoe Down Yard, are owned by PG&E.

Why is PG&E cleaning up the former Potrero Power Plant property?

While PG&E no longer owns the former Potrero Power Plant, we are taking responsibility for the impact of our operations. Investigations will be conducted subsequent to the former plant's demolition by GenOn Potrero LLC, and a cleanup plan will be formulated based on site data and anticipated future use.

Who is overseeing the remediation?

PG&E is working under the oversight of the Regional Water Quality Control Board, San Francisco Bay Region, an organization within the California Environmental Protection Agency, which is the lead agency overseeing the environmental investigations and cleanup at the site. In addition, PG&E is coordinating remediation efforts with the City and Port of San Francisco and several other local, state and federal agencies, including the California Department of Fish and Game.

Are there health risks to the community as a result of impacts to the soil, groundwater, surface water and sediments?

No. All information that we have collected to date indicates that there is no health risk to the public from environmental impacts.

What formal procedures has PG&E put in place in order to ensure community members have an opportunity to comment on the remediation and cleanup plans?

We have put together a comprehensive community outreach plan for this site. Our community outreach efforts include regular project newsletters, community planning meetings and stakeholder outreach. Newsletters with site updates are periodically mailed to approximately 1,400 local residents and key stakeholders. In 2012 we held two community meetings to discuss PG&E's efforts at the site with the community and incorporate input into our cleanup plans. In addition, the Water Board has a public participation program for the site. Community members are invited to comment on draft feasibility studies and cleanup plans as part of the Water Board’s review process. The Water Board also invites community members to participate in Public Meetings. In 2012, the Water Board solicited feedback to inform the final cleanup approach for the Northeast Area. All members of the community are encouraged to contact the project team via the contact information listed on the right hand side of this page.

NOTE: Although the parent corporations, NRG and GenOn, have merged, the wholly owned subsidiaries have not merged or changed names, so GenOn Potrero, LLC remains the owner and operator of the Potrero Generation Stations