The rail car that spewed nearly 20,000 gallons of toxic herbicide into the Sacramento River eight days ago was of an older design so notorious for rupturing that federal investigators have repeatedly urged that it not be filled with hazardous cargoes.
In dozens of accidents in recent years, the National Transportation Safety Board has found that the DOT-111A -- the most common tank car on the nation's rails -- punctures twice as easily as newer cars with stronger shells and special safety features.
Yet the U.S. Department of Transportation has been slow to upgrade its design standards or require that dangerous loads be put in sturdier cars, and the DOT-111A's still account for roughly 60,000 of the 107,000 tank cars used to haul hazardous loads all over the country.
"They're perfectly satisfactory for carrying many materials out there," said Bernard Loeb, director of research and engineering at the safety board, the leading federal agency in accident NTC investigations. "But there are still a number of products being transported in these 111As that we believe should not be."
With more and more of the nation's chemical cargoes being moved by train, the disastrous spill from a Southern Pacific derailed train on July 14 near Dunsmuir is focusing new attention on a haphazard regulatory system that allows rail lines to handle many toxic materials no differently than they handle wine or corn syrup.
The spill left 45 miles of the upper Sacramento River virtually lifeless, killing fish, plants and insects. But despite the potency of the pesticide, it was not considered "hazardous" by the U.S. Department of Transportation, so it traveled unlabeled in an ordinary tank car.
It now appears that the Southern Pacific train derailed because too much weight was concentrated at the end of the train. But some experts contend that a sturdier tank car may not have punctured so easily in the 20-foot fall and that, at the very least, placards identifying its cargo as hazardous would have prompted a speedier response.
Even Southern Pacific acknowledges that the crew should have known more about the contents of the tank car.
If metam-sodium, the spilled herbicide, were regulated as a hazardous material, "the crew would have had a very detailed printout on the characteristics of the chemical, including recommendations on what to do in just such a circumstance, said Southern Pacific spokesman Mike Furtney. "It would have generated a very different type of response.
"Instead, they had a one-line reference [on a manifest] which said that they were dealing with a weed killer," he said.
U.S. Transportation Secretary Samuel K. Skinner has promised a review of rules covering metam-sodium. However, he is also defending his agency's track record in regulating the movement of hazardous materials over the nation's rails.
Mr. Skinner's response appears to typify the reactive "chemical-by-chemical" approach that, according to the agency's critics, has been an underlying factor in a string of toxic rail disasters leading up to last week's spill.
Chief among the critics is the safety board, an independent watchdog agency, which for more than a decade has pressed the Department of Transportation to take a more systematic approach to regulating hazardous cargoes -- with only limited success.
"Progress has been slower than the safety board would like to see," spokesman Brent Bahler said.
Just two months ago, the safety board called for "immediate action . . . to identify the most harmful materials that pose the greatest risks and to have those materials transported in improved tank cars."
In particular, the NTSB singled out the DOT-111A tank cars, saying that their "inadequate protection and poor performance" have been "evident for many years."