"We would have to move if this line is built too close to our property. We don't want to take the risks," she said.
California's push to build more transmission lines to satisfy growing demand for electricity is stirring concern over possible health effects from electric and magnetic fields -- EMFs -- created by electricity lines.
Angry homeowners in the paths of big transmission projects near San Francisco and in Southern California have bombarded state utility regulators with pleas to detour the lines away from homes, schools and offices.
A review of scientific studies by the state's Department of Health Services said there was no conclusive evidence that EMFs are harmful but studies have suggested links to childhood leukemia, adult brain cancer, Lou Gehrig's disease and miscarriage.
The Edison Electric Institute, a utility industry trade group, said "although several studies conducted in the past suggest a link between proximity to power lines and some forms of childhood cancer, only a few show a statistically significant link and many show no link at all."
"Nationwide, EMF concerns have receded significantly over the years, and much of the opposition to new transmission projects has been of the garden-variety NIMBY type," said Jim Owen, an EEI spokesman. "However, EMF as an issue is unlikely ever to disappear entirely."
But Loretta Lynch of the California Public Utilities Commission said it was time the agency reexamined the EMF health situation "to see if we need to revise policies on transmission projects." The agency expects to get still more power line proposals for urban areas.
Despite strong opposition from EMF foes, the CPUC in July narrowly approved two transmission plans in Orange County and San Diego, but left the $207 million, 27-mile-long San Francisco area project for a decision in August.
California utilities, under pressure from the CPUC, are launching new transmission lines in fast-growing suburban areas to make the power grid more reliable.
More transmission capacity and new power plants aim to avert a rerun of California's electricity crisis in 2000-2001, when a supply shortfall triggered blackouts and the bankruptcy of PG&E Corp.'s Pacific Gas & Electric utility, the state's biggest.
Lighthouse, a mother of two young children, and several hundred of her neighbors in the San Francisco suburb of Burlingame fear that EMFs are harmful and want the PG&E line moved about a mile away from their homes and buried at least 11 feet deep.
"We are very concerned about EMFs and health risks. They have to be taken into account when routing power lines, so people are not exposed to high levels," Lighthouse said.
Underground lines usually are buried about 5 feet to 6 feet, but Paul Moreno, a PG&E spokesman, said the utility could go to 11 feet but does not want to shift the alignment as far as the neighbors do.
"EMFs are used in efforts to stop or realign transmission projects," he said. "The reality is these lines give off very low levels of EMFs at the right of way, far lower than you would find in homes, offices and schools."