Pesticide Flows Into Shasta Lake; Residents Outraged : Environment: State is criticized for inability to stop flow. Officials predict that threat to drinking water will end before the chemical reaches dam.

A toxic green river of pesticide poured into Lake Shasta early Wednesday as scientists carefully tracked the chemical’s potential threat to the state’s drinking water supply and an army of frustrated officials from a dozen public agencies stood by helplessly, unable to stop the flow or clean up the contamination.

The foul-smelling plume of poisonous metam-sodium, which already has killed all aquatic life along a 45-mile stretch of the upper Sacramento River, slowly spread from shore to shore as it entered the northernmost finger of California’s largest reservoir.

Tests of water samples showed that the pesticide levels had dropped substantially, but the concentrations remained hundreds of times higher than that lethal to fish. Nonetheless, experts insisted that the 19,000 gallons of pesticide spilled in Dunsmuir from a derailed Southern Pacific tanker car Sunday night would be diluted to benign levels by the time it reaches Shasta Dam at the lake’s southern end.

Local authorities, worried about persistent acrid vapors that have sickened scores of people since Sunday, continued to advise residents to stay away from the fouled stretch of river. It was unclear how many people had evacuated their homes, but regional hospitals were treating a trickle of patients complaining of nausea, dizziness and headache.

A biologist who surveyed the toxic river reported seeing one bear, two deer and one river otter dead on or near the banks of the contaminated river, but their cause of death had not been established. Endangered California bald eagles were sighted eating poisoned fish, raising concerns they too may die.

Meanwhile, anger was mounting among townsfolk and local business owners unhappy that the team of scientists, experts, state cabinet members and Southern Pacific officials seem unable to do anything but monitor the spill, bemoan the devastation and hold briefings on the location of the plume.

Gov. Pete Wilson, at a press conference in Sacramento, called the spill “tragic” and vowed to ensure that the railroad covers costs associated with the disaster--including those borne by tourist-dependent businesses.

But that was of little consolation to local residents, who criticized the state for not halting the 11-mile-long stream of poison before it reached the reservoir.

“To let it go all the way to the lake, something’s wrong,” said Virgil Ohmae, owner of the Top Hat Cafe in Lakehead. “It’s a total mess what they did out here.”

Top state officials, however, said they had little choice but to let the slick enter the lake because of the rugged terrain and the nature of this particular chemical.

“Once the material was in the water, under the circumstances that we had here, there became very little we could do to remove it,” said Peter Bontadelli, director of the state Department of Fish and Game.

Unlike an oil slick, the pesticide is water soluble and mixes thoroughly with water. As a result, setting up booms and skimming the surface of the river would have been ineffective, Bontadelli said. Damming the river--even if it were physically possible--would have created a pesticide lake, potentially causing even more harm, he said.

Also Wednesday, environmentalists attacked the federal government for failing to adequately regulate the transportation of dangerous materials. Metam-sodium, a soil fumigant, is not among more than 2,000 chemicals listed as hazardous materials by the U.S. Department of Transportation.

As a result, there was no federal requirement that the rail car be labeled, and no requirement that the crew be specially trained in how to handle an accident. This, authorities said, contributed to initial confusion over the identity of the chemical and uncertainty about the severity of the spill.

“There is nobody minding the store in this industry,” said Fred Millar, toxics director for the Friends of the Earth in Washington. “This chemical wasn’t even listed as hazardous by the Department of Transportation and it has wiped out an entire river.”

Millar and several local residents said federal transportation officials should exert more control over the routing of hazardous substances, particularly through tricky corridors such as the stretch of track where the Siskiyou County derailment occurred.

“This was bound to happen, and I think it’s time they look at a ban on the transportation of certain chemicals up this canyon,” said Tom Hesseldenz, a biologist who lives in the city of Mt. Shasta. “They transport chlorine gas up through there. The potential for a much greater disaster clearly exists.”

Southern Pacific spokesman Andy Anderson said the track through Dunsmuir “is the main line between California and Oregon. That’s not a line you can just close down.” So many vital substances are classified as hazardous, he added, that a blanket ban is impractical.

As state and federal investigators continued to probe the derailment, Southern Pacific resumed service on the line. The railroad also temporarily changed its rules regarding the use of so-called “helper,” or extra, locomotives in response to suggestions that the lack of such an engine may have contributed to the derailment.

Typically, Southern Pacific requires a helper locomotive on trains weighing 4,500 tons or more. (The train that derailed weighed 4,290 tons and did not have a helper unit.) Now, the railroad is requiring helper engines on trains weighing 3,500 tons or more, Anderson said.

“It’s just a precautionary measure,” he said.

As movement of the contaminated area began to slow down, officials expressed optimism that it would not endanger the drinking water supply. The Sacramento River is the main pipeline for water moved from the federally operated Shasta Dam and the state-operated Oroville Reservoir to cities and farms farther south.

Kassy Perry, associate secretary for public affairs for the state Health and Welfare Agency, said the plume “seems to be degrading as it’s moving.” Nonetheless, health officials intend to remain on the scene for weeks and will take water samples as frequently as every 90 minutes.

Moreover, because of lingering uncertainty about the chemical behavior of metam-sodium, officials remain prepared to shut down Shasta Dam at a moment’s notice, Perry said.

“A lot of this chemical stuff, were really in the dark on it,” said John Watt, a state Department of Forestry official who was sent out to survey the leading edge of the slick.

Among the unknowns is whether the chemical will move across the lake “in one big glob” or spread out, Perry said. Wednesday night, officials reported that the plume was sinking to the bottom of the lake, but they were unable to explain the consequences.

Mike Rode, a biologist for the Fish and Game Commission, said fishery experts fear the chemical may reach the dam in heavy concentrations.

“The worst fear of all is that the . . . plume will go out the dam, affecting the winter-run salmon with the toxin,” Rode said. Salmon spawn in the cool water just below the dam.

Meanwhile, state officials continued to grapple with possible remedial measures. They considered trying to pump out the contaminated water, but launching such a massive operation and finding a way to dispose of the tainted water would prove too great a challenge.

“At this time, it certainly isn’t practical,” said Bill Gengler, a spokesman for the Department of Fish and Game.

Experts said the decimated river, while sterile today, would eventually recover. How quickly it rebounds depends in part on whether the chemical persists in sediments and how soon plant life and aquatic invertebrates that form the bottom rung of the food chain recolonize. To aid the recovery, top Fish and Game officials in Shasta County recommended that fishing be banned indefinitely on river tributaries and in waters above the spill.

As the plume passed the tiny vacation community of Lakehead, dozens of fish could be seen swimming just ahead of it. Some circled back repeatedly, but stopped each time they reached the slick.

Residents were irate about the disaster--and how government agencies have handled it. Local authorities have issued inaccurate and conflicting information, they said. Warnings often have been slow in coming. And the ongoing voluntary evacuation has unnecessarily driven away business, they complained.

“There’s been very poor communication,” said Sandra Wood, owner of Shasta Lake Auto Repair. It hasn’t helped, she said, that officers placed a sign in the road in front of her shop that reads: “Area Closed to All Access Due to Chemical Spill. No Swimming. No Drinking. Don’t Touch the Water.”

In other developments, San Francisco attorney Melvin Belli met with the community of Dunsmuir on Wednesday. The local radio station broke into its broadcast of the San Francisco Giants game to announce the unusual meeting.

Also, Rep. Barbara Boxer (D-Greenbrae) asked the U.S. General Accounting Office to investigate the derailment.

Times staff writer Virginia Ellis contributed to this story from Sacramento.