A handful of Marina residents will relocate at PG&E’s expense this summer so the utility can remove chemical residues left behind by three former coal gas facilities during the 19th and early 20th centuries.
Before the widespread discovery of natural gas, gas produced from coal and oil was the primary source of gaseous fuel for lighting, heating and cooking. PG&E closed most of its manufactured-gas plants more than 75 years ago, including three in the Marina. Two other facilities were destroyed in the 1906 earthquake and subsequently buried beneath rubble from the disaster.
PG&E began a voluntary investigation of residual materials at former manufactured-gas plants in the Marina and Fisherman’s Wharf in February 2010. The testing was done in consultation with property owners, city and county officials, and the state Department of Toxic Substances Control.
Over the past 18 months, the utility has sampled soil and found potential residues at depths from
1½ feet to 10 feet below the ground. Residues from the operation of such plants may include coal tar and spent coal or coke, as well as various chemical compounds such as polycyclic aromatic hydrocarbons.
Allan Fone, a project manager with the Department of Toxic Substances Control, said his agency concluded that area residents were unlikely to come into contact with the contamination under existing conditions.
However, PG&E spokeswoman Nicole Liebelt said the utility wants to responsibly clean up after its previous operations because impacted soil could possibly be brought to the surface in the future, and a cleanup would ensure the ongoing protection of the community and environment.
“While results to date indicate there is not a current health concern … under existing conditions, results in some locations may warrant cleanup activities,” Liebelt said.
A spokesman for the Bay Area Air Quality Management District appeared to share that assessment.
“If the soil is disturbed, there may be a chance that volatile organics could form,” air district spokesman Ralph Borrmann said. “But microbes in soil tend to digest these things, and since it has been such a long period of time, it seems that this is not so much an air quality issue at this point — unless they uncover something else.”
The Department of Toxic Substances Control views the goal of PG&E’s efforts as determining whether existing residues could pose any adverse health impacts.
PG&E plans to remove residues from three properties on Beach Street and two on Fillmore Street.
At the property owners’ request, Liebelt said, PG&E is providing comparable temporary housing for residents during the project, which is expected to take anywhere from six weeks to four months to complete.
Liebelt said the utility informed the community by sending out mailers, canvassing the neighborhood and holding community meetings. It also invited the Marina Community Association to get involved.
“They sort of downplayed the toxicity of it all,” said Kat Anderson, vice president of the Marina Community Association. “The way they portrayed it was that you pretty much had to dig up the sidewalk and roll around in it and eat it before it would hurt you.”
The utility has opened a resource center near the Marina Safeway and held open houses to educate the neighbors about the issue. The center at 1593 North Point St. is open during normal business hours.
“Anything having to do with toxins is always interesting, but I don’t know enough to know whether I should be concerned or not,” said Marina resident Peter Rosenthal, who remembered receiving information about the project when it first began.
But such knowledge can be scary, Anderson observed.
“There was trickiness to it, because property owners that were affected by it didn’t want to know too much, because then they would have to disclose the information and it might lower their property value,” she said. “Another concern was that we all knew the stuff was in the Bay, and when we asked what they were doing about that, they were a little vague.”
The North Beach plant was located at the edge of the historic shoreline at the East Harbor Marina. Sampling done by PG&E indicated that the deeper layer of sediments in the East Harbor do contain energy plant residues, Liebelt said, and the company has been working with the San Francisco Recreation and Park Department for several years to address this issue.
Liebelt said PG&E is working to figure out whether there is a potential for movement of any residues into the sediments from the shoreline.
“We will continue to work with the S.F. Recreation and Park Department and will take any necessary action for the long-term protection of the Bay,” Liebelt said.