continued Tyvol inadvertently discovered SDG&E's failure to give the Public Utilities Commission notices. After learning how high electromagnetic-field emissions were on Dale Street, he wrote to the city's planning department requesting the "advice letter" that the notices had gone out. (Utilities are required to file such advice letters with the commission, the California Energy Commission, and the local planning director.)
"I wrote a formal request to see the advice letter," says Tyvol, "because officials take you more seriously that way. But I had to follow up, because they lost my letter. They're nice people in the planning department but not very organized. Eventually they discovered that they never received the advice letter I inquired about."
Finally, Tyvol's complaint to the Public Utilities Commission charges that, in its Dale Street project, SDG&E did not take the steps to mitigate electromagnetic radiation that the utility's own "design manual" says have some impact. The company did not bury the power cables in the center of the streets, but closer to their eastern edges. The company dug only a three-foot-deep trench to bury the lines, so that by the time the lines were placed on the bottom of the trench, they were 24 inches from the surface, the minimal depth the law allows. When Pacific Gas and Electric undertook a similar project in San Francisco, says Tyvol, the Public Utilities Commission required it to bury the cables 11 feet deep, to keep them farther away from pedestrians.
In the meantime, a national debate rages over how harmful electromagnetic-field radiation is to humans. Hal Tyvol admits that no "conclusive" proof exists that the radiation is dangerous. But he cites a 2002 report by the California Department of Health Services that "it is more probable than not" that radiation is a factor in the development of childhood leukemia, miscarriages, brain cancer, and Lou Gehrig's disease. Other studies have established a "statistically significant correlation" between radiation emissions and the diseases. "The power industry," says Tyvol, "admits to the correlations but argues the diseases may come from other factors, such as pollution, and not from electromagnetic fields. The problem is that you can't do laboratory testing on people like you can on rats."
Stephanie Donovan, a senior communications manager for SDG&E, responds, "The issue is an emotional one. The danger can't be ruled out. But most studies don't demonstrate that it exists." Donovan referred me to a link on SDG&E's webpage. It reads in part: "Without exception, the major scientific reviews of the [electromagnetic- field] research literature have reported that the body of data, as large as it is, does not demonstrate that exposure to power-frequency magnetic fields causes cancer or other health risks, although the possibility cannot be dismissed.... Has science proved [electromagnetic-field radiation] is harmless? No, scientific uncertainty remains and research is ongoing."
That must be the reason that California's Public Utilities Commission insists that utilities put metal shielding around cables carrying more than 5000 volts of power.