In a showdown that pit antinuclear activists against marine-mammal supporters, the California State Lands Commission approved PG&E’s plans to begin conducting high-energy 3-d offshore seismic tests to determine the extent to which the faults offshore from the Diablo Canyon Power Plant in Avila Beach connect. That information, in turn, will be used to determine more precisely the seismic threat posed by a new fault line — the Shoreline Fault — discovered in 2008 about 100 meters away from the nuclear plant and whether additional safeguards are need to prevent a Fukushima-type disaster in the event of an earthquake.
Opposing PG&E at the State Lands Commission 10-hour hearing was a coalition of environmentalists concerned that the high-pressure sound guns PG&E will be blasting into the waters off its nuclear plant — 24 hours a day for 33 days — could prove damaging, if not fatal, to blue whales, fin whales, humpback whales, California sea otters, and harbor porpoises in the area. The Natural Resources Defense Council warned that the loud blasts could deafen the porpoises, which rely heavily upon their sense of hearing for their survival. Native American activists worried that the testing equipment could disrupt ancient villages now located underwater. Fishermen said the blasting could put them out of business. And San Luis Obispo County Supervisor Bruce Gibson, a research geophysicist, objected that PG&E was not using the very best equipment possible.
By leasing a seismic testing boat from the oil industry rather than a research vessel from Columbia University, Gibson suggested PG&E could get better resolution images — as deep as 15 kilometers below the surface — and in less time with less adverse impact to the marine environment. Because this issue was not raised until just recently, the State Lands Commission staff ruled it came too late to be considered in the Environmental Impact Report just approved. But in defense to the environmental concerns, the State Lands Commission voted to delay the time the testing could begin — moving it from September 15 to November 1. This delay will soften some of the impact on sea life. And the testing will be accompanied by monitors in boats and aircraft; if sea mammals are spotted, the testing will be stopped.