As city officials in Tiburon agonized over how to get rid of the carcass of a 30-ton gray whale that washed up on the beach, would-be good Samaritans hauled it out to sea. But it came back, smelling worse than ever. This time it was in Pacifica, about 15 miles south of Tiburon, and its stench wafted along Main Street's scenic restaurant row, several hundred yards from the beach. Police Lt. John Gurney said Pacifica authorities were not taking any chances with the 41-foot whale that was estimated to have been dead two weeks. After conferring with the California Academy of Sciences in San Francisco, Pacifica officials decided to have the beast sliced into pieces, loaded on a truck and buried. The body was hauled away to a landfill site in Livermore.