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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 1996, 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 many 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?

PG&E has made significant progress on the environmental investigation and remediation of the Former Potrero Power Plant Site. The site has been divided into seven work areas to facilitate the remediation process. This allows for the investigation and remediation of certain areas to proceed while further studies are needed in others and some areas remain inaccessible because of existing structures. Most investigation activities have been completed in the accessible areas. Other remediation activities, including conducting feasibility studies, health risk assessments, and remedial action plans, are in various stages of completion.

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 Areas, 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. The first community newsletter was sent to approximately 1,400 local residents and key stakeholders in September 2011 and updates were sent in November and December of 2011. This year we will be organizing 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 process for the community to review cleanup plans before they are implemented.