A 2001 study of the Dunsmuir metam sodium spill suggested the green gas it created exceeded lethal levels for human inhalation for several hours, but no fatalities were reported. Credit: California Department of Fish and Wildlife

DUNSMUIR, Calif. – Every 20 minutes, a train hurtles over the Sacramento River, through the Cantara Loop. And half a continent away, at nearly the same frequency, a train crosses the Mississippi River.

Train cars can carry toxic chemicals or crude oil, but the public rarely knows what’s inside. Dangerous materials are routinely, and quietly, routed over waterways and through communities.

On the evening of July 14, 1991, one train broke the peace in the small town of Dunsmuir.

Naomi Croft remembers the incident well. She heard a loud crash and “all of a sudden, it turned green outside.”

Upriver from Croft’s house, a train car went off the Cantara Loop bridge. The accident spilled 19,000 gallons of metam sodium, a pesticide, into the Sacramento River below.

When a toxic material spills on land, it often can be contained. But when substances spill into a river, the water can carry chemicals many miles downstream.

The pesticide that spilled into the river is a fumigant. So, when combined with water, it created a toxic gas that billowed 45 miles downriver to Shasta Lake, where the chemical dispersed.

The 1991 spill is considered one of California’s worst environmental disasters.

The Cantara Loop was the site of one of California’s worst environmental disasters. On July 14, 1991, a train car went off the Cantara Loop bridge, spilling 19,000 gallons of the pesticide metam sodium into the Sacramento River. Credit: Theresa E. Soley Credit: Theresa E. Soley

Yet more than 25 years later, the National Response Center database, managed by the U.S. Coast Guard and used by the Environmental Protection Agency, still lists “0” as the amount spilled into the river. In the database, federal agencies never have listed the amount of metam sodium that seeped into the ecosystem.

An examination of the database, funded by Marquette University’s O’Brien Fellowship for Public Service Journalism, found that the federal government routinely fails to list the amount of toxic chemicals spilled into the nation’s waterways, leaving the public in the dark about spills’ impacts on residents, neighborhoods and the environment.

According to the federal database, there were 295 chemical spills from trains into the Mississippi River in 2015 alone, or nearly one every day. That total is actually down somewhat from recent years. Although many of the reported spills were small, the database failed to list the amount spilled in 188 incidents, or more than 60 percent of the spills.

Dave Hokanson, deputy director of the Upper Mississippi River Basin Association, an interstate organization responsible for monitoring issues affecting the waterway, said he and his colleagues found the database useless when it came to calculating the quantity of chemicals spilled into the river.

“What does it mean if no volume has been reported?” he asked.

He thinks the information exists elsewhere but is fragmented and held by many different government organizations. Hokanson said more complete spill information would be useful to his organization and the general public.

“The information is there, it’s just not compiled,” he said.

The Coast Guard and EPA acknowledge the information gaps but have done little to fill them.

“The quantities will be an issue because … we can’t verify what’s actually being reported to us,” said Lt. Harry Carter of the Coast Guard’s response team in Washington, D.C.

A spokesman for the EPA, which responds to spills, wrote in an email that “the database is not intended to track spills beyond initial notification; and while available for public review, it is intended as an internal database rather than a public tool.”

The Coast Guard records spill information from those who report the spills, the EPA often responds to these notifications, and then the database can become neglected. And there is no other complete set of data available to the public that tracks chemical spills.

Frequency of chemical spills in the Mississippi and Sacramento rivers

The National Response Center database reveals a significant decrease in the frequency of spills into the Mississippi River over the last 25 years. It also indicates that in 2015, spills into the Mississippi were 36 times more frequent than spills into the Sacramento River. The Mississippi is five times the length of the Sacramento, but the frequency of spills into the Mississippi greatly exceeds this ratio. The numbers reported in this table are those reported in the federal database, but because the records contain so many holes, the numbers may be inaccurate.
RiverNumber of spills
Source: National Response Center. Data analysis by Cara Lombardo of the Journal Sentinel in Milwaukee.


The Upper Mississippi River National Wildlife and Fish Refuge occupies 240,000 acres in Wisconsin, Minnesota, Illinois and Iowa.

It is a flyway for migrating birds and an aquatic home to federally endangered species, including winged mapleleaf and fat pocketbook mussels. Tracks crisscross the refuge, and passing trains carrying all sorts of cargo follow these paths.

A series of large spills has plagued the area in the past two years. On Nov. 7, 2015, a train derailed near Alma, Wisconsin, spilling an estimated 18,000 gallons of ethanol into the Mississippi River within the wildlife refuge.

Kathi Korum remembers receiving a phone call at her quilt shop across from the river. “Train derailment,” she heard a muffled voice say, before the call was disconnected.

She later found out that houses to the north of her street were alerted of the spill and given a voluntary evacuation warning. She posted a note on the door of her shop that read, “Closed due to train derailment.”

Then she and her boyfriend drove up the cliffside above the river to see the disheveled train cars for themselves.

Earlier that year, in February, a crash near Waupeton, Iowa, spilled 30,000 gallons of ethanol into the river. Then a month or so later, an incident near Galena, Illinois, spilled 140,000 gallons of crude oil into the waterway.

In January 2016, 850 gallons of vegetable oil spilled from a train accident near Brownsville, Minnesota. In September, an estimated 1,000 gallons of diesel spilled into the river near Ferryville, Wisconsin.

These five spills alone dumped nearly 190,000 gallons of toxic chemicals into the upper portion of the Mississippi. Chemicals flow downstream toward the Gulf of Mexico until a response team arrives at the scene.

Lark Weller, water quality coordinator with the Mississippi National River and Recreation Area, said the health of the Mississippi is concerning, as some areas already fail to meet federal standards for contamination, including excess bacteria, phosphorus and nitrate.

Weller is a lead author of the 2016 State of the River Report, an assessment of the Mississippi and its ecosystem published in September.

The report found the greatest source of chemical contamination to the Mississippi is agricultural runoff. Although train spills are also a source, Weller said her team doesn’t receive much information regarding this means of pollution, including spill volumes.

Weller also said rail companies aren’t transparent with spill information, even though they are legally required to report all spills to the Coast Guard.

“It’s sort of difficult to get information from them,” she said.

On a spring day in the refuge, the sky is softly colored and the river calm. An unseen whooping crane, another endangered species, croaks before its broad black wingtips break the bird’s hiding act. Ducks of many species conduct a gentle symphony. When a train rushes through, the birds are startled into flight, leaving the expanse of water empty.

The impact of chemical spills into rivers remains unknown.


In California in 1991, the damage from the Cantara Loop spill was obvious. As the metam sodium traveled downriver, it killed all life in its path: fish, mollusks, salamanders, even trees that lined the riverbanks.

A 2001 study in the Journal of Toxicology and Environmental Health suggested the green gas created by the spill exceeded lethal levels for human inhalation for several hours, but no fatalities were reported.

Some residents, though, believe they face health repercussions today.

Rich Weir, 60, says he had swelling in his lips and genitals within a year of the 1991 metam sodium spill in Dunsmuir, Calif. He also started itching. The spells lasted five years. Credit: Theresa E. Soley Credit: Theresa E. Soley

Rich Weir, 60, works at the only hardware store in Dunsmuir and has a woodshop in his basement. He’s lost two fingers to his hobby.

Weir harvests timber from the surrounding forest, but only from trees already downed by natural causes. He hauls the salvaged wood to his shop, where he processes it into boards and creates pieces such as instruments.

“I’m a Buddhist tree hugger,” he said.

Weir was asleep when the plume of metam sodium passed through the community. While he said there was no official government warning after the incident, the following days were abuzz with rumors and chatter.

“No one ever knocked on our door,” he said.

Metam sodium is a pesticide used in agriculture to kill weeds, fungi and insects. The EPA now says people who come in contact with the chemical should have proper training. In some situations, it urges those using the pesticide to wear respiratory masks.

The Journal of Toxicology report found that exposure to the pesticide can cause skin, eye and respiratory irritation. It also could increase the likelihood of allergy development and induce spontaneous miscarriages. The study exposed lab rats to metam sodium and documented developmental abnormalities, neuroendocrine changes and cancer in those exposed.

State data suggests that in the days following the 1991 spill, 705 people sought medical care for ailments such as headaches, nausea, eye irritation, dizziness and shortness of breath. Twenty new cases of asthma were documented by health clinics.

Weir remembers experiencing swelling in his lips and genitals within a year of the spill. He also started itching. “I’d never itched in my life.”

He said the spells lasted five years. He spoke with a doctor and received medication, but said the problem never was diagnosed formally. His wife got the itches, too.

In 1993, the law firm Kershaw, Cook & Talley won a $15.5 million settlement in a class-action lawsuit against the Southern Pacific Transportation Co., the train company responsible for the spill.

According to Weir, residents received a few thousand dollars per person. He said there was also a medical trust fund created in anticipation of future health repercussions for residents.

While Weir has no children of his own, his wife has three – twin sons who were 10 at the time of the spill and a daughter who was 13.

Weir now has two grandchildren who live nearby. He said one has unexplainable seizures, and the other has both physical abnormalities and stomach problems. He worries that these medical issues could have been caused by their parents’ metam sodium exposure, though there is no research to confirm this.

“We don’t know, but maybe,” Weir said.

When asked whether he believes the government would be more transparent if a spill occurred today, he replied, “Nothing has changed.”


Naomi Croft, 74, has been living in the same house above the Sacramento River in Dunsmuir, Calif., since 1968. Following the 1991 spill, she said she developed asthma. She thinks going outside right after the spill caused her health problems. Credit: Theresa E. Soley Credit: Theresa E. Soley

Naomi Croft, 74, has been living in the same house above the Sacramento River since 1968. She raised three daughters there, but only one, then 12, lived with her at the time of the spill in 1991.

Croft, too, grew up in the canyon. Its steep walls stretch upward from the Sacramento River, blanketed in green foliage.

Before an emerging train can be seen at the Cantara Loop bridge, the forest trembles, then the tracks begin to vibrate. The sound of the oncoming engine intensifies, followed by a locomotive that pierces through the woods, toward the river.

“Strange, but home,” Croft said of Dunsmuir.

Following the spill, Croft said she developed asthma. She thinks going outside right after the spill caused her health problems.

“I was in green,” she said of the gas cloud.

She called the police department after exposure to the gas but said officers wouldn’t tell her what was going on. She said the police eventually informed her of the train accident but didn’t answer when asked whether the chemicals in the air were toxic.

Croft said she received a financial settlement for her family from Southern Pacific, though she is barred from disclosing the amount. “It wasn’t enough,” she said.

Croft said she never was evacuated from her neighborhood or officially informed of the spill by the government. And she said the toxicity of metam sodium never was described to residents.

She remembers rumors passing around Dunsmuir that everyone had 50 years of life left after the spill. The community, she said, was termed “the valley of death.”

In 1989, Dunsmuir’s per-capita income was 49 percent of the state of California’s. In 2015, it was lower, about 44 percent when compared with the rest of the state.

Following a decline in railroad jobs in the 1950s, fly-fishing tourism provided an economic boost for the city. After the metam sodium plume came downriver, the California Department of Fish and Game (now known as the Department of Fish and Wildlife) closed the river to anglers for three years.

Mark Stopher, senior policy adviser for the department, estimated some 1 million trout in the upper Sacramento River were killed by the spill. The pause of fishing was hoped to allow the population to rebound.

Another $38 million settlement with the state and federal governments created the Cantara Trustee Council, which funded a group of scientists to monitor river health until 16 years after the spill, and there are some signals of recovery. First, algae came back, Stopher said. Next came insect larvae, and fish swam back into the river to eat them.

The council also found that amphibians such as Pacific giant salamanders could take 35 years to repopulate the river to prespill numbers. The Department of Fish and Wildlife said one scientist believed a species of mollusk, Fluminicola seminalis, could be locally extinct in parts of the river because of the spill.

Today, some trees along the river still stand dead, skeletal remains of the past.

The Cantara Trustee Council suggests in its last publication that by 2031, regenerated trees should be back to prespill heights.


A train rolls by the Sacramento River near Dunsmuir, Calif. In its National Response Center database, the federal government routinely fails to list the amount of toxic chemicals spilled into the nation’s waterways. Credit: Theresa E. Soley Credit: Theresa E. Soley

Wayne Eng has been a fishing guide on the Upper Sacramento River for 20 years. He bought his waterside house in 1991 right before the spill, but rented it out while he lived in Sacramento for three years.

Eng avoided the incident and three years of aftereffects to fish populations.

When the state reopened fishing in 1994, Eng and his wife moved into their Dunsmuir home. He said there are good years and bad years when it comes to fly fishing, but trout numbers are pretty steady today.

He said some good things have resulted after the spill. The ecosystem proved resilient, and children are receiving environmental education initiated by settlement funding.

In the shadow of Mount Shasta, a dormant volcano, Eng tosses a fly. But he still worries for the future.

“It’s just a matter of time,” he said, until there’s another spill in his precious fishing grounds. “It’s kinda like that volcano. It’s sleeping, but it’s gonna pop.”

This story was funded by the O’Brien Fellowship for Public Service Journalism. It was edited by Greg Borowski of the Journal Sentinel in Milwaukee and Miranda S. Spivack, Pulliam Distinguished Visiting Professor of Journalism at DePauw University. It was copy edited by Nikki Frick of Reveal from The Center for Investigative Reporting.

Theresa E. Soley can be reached at theresa.soley@marquette.edu.