Rural Missouri Magazine
A monument
to the times

From defense plants to hazardous waste sites, Weldon Spring's history has paralleled that of the U.S. in the 20th century

by Jeff Joiner

Visitors to the Weldon Spring waste disposal cell climb stairs leading to the top of the 45-acre stone mound containing tons of hazardous waste. Unlike many hazardous waste sites, the Weldon Spring site, which includes an interpretive center, is open to the public. Visitors can learn more about the area’s often controversial history.

It’s unusual enough that when motorists driving west on Highway 94 see it they often do a double take. Rising out of the ground like some kind of brilliant white ancient burial mound, the dome can easily be seen for miles around. It draws thousands of curious visitors each year to Weldon Spring despite the tons of hazardous waste entombed within this huge rock dome.

“People come in here and say, ‘I can see the top of this thing from my house in Windhaven,’ which is a major subdivision up here. ‘What is it?’”says Yvonne Deyo, director of the Weldon Spring Site Interpretive Center in St. Charles County just south of Highway 40.

The Weldon Spring site has gone from massive defense plant to abandoned industrial waste dump to a cleaned up hazardous waste site. Today, it welcomes visitors to prairies, gardens and bike trails. The site’s history is both sad and encouraging.

Deyo says it surprises many people that the highest point in St. Charles County is not a rocky bluff towering above the Missouri River, but the top of the Weldon Spring waste disposal cell. It might also surprise people that they can visit the site and climb stairs to the top of the 75-foot tall mound where placards tell the story of communities that disappeared in 1940 to make way for the world’s largest explosives factory.

Visitors can also visit the interpretive center at the base of the 45-acre disposal cell and learn about the monumental effort to clean up decades of hazardous waste left behind by the World War II and Cold War defense plants. Deyo says they will learn the history of this area and experience a new approach the United States government is taking to clean up hazardous waste sites it created and educate the public about its efforts.

Weldon Spring Interpretive Center Director Yvonne Deyo stands on a map of the original 17,000 acres of land taken to build the World War II explosives plant at Weldon Spring.

“We are one of the first cleanup sites of this type to reach completion,” says Deyo, who adds that because the Weldon Spring site is so close to populated areas it had to be handled in a unique way. “Most federal cleanup sites are out West and in places were there aren’t a lot of people. We are very close to a major metropolitan area and that makes us very different.”

One and a half million cubic yards of hazardous waste were contained in the disposal cell, a process begun in 1997 and finished in 2001. The remainder of the site began a transformation from industrial complex to natural tall grass prairie. Gone are the fences and signs warning of radioactive contamination.

“This is a new approach the Department of Energy has taken to try to continue long-term community education. Instead of keeping the site closed off to the public and not having people aware of what is going on here, bring them in, make them aware of what’s here and what’s going to be here.”

The completion of the waste disposal cell in 2001 marked the end of five decades in which the Weldon Spring site was a crucial part of the country’s national defense, which began just before the outbreak of World War II. The story’s beginning is a sad one, says Deyo, who adds the area’s fate was sealed in the early 1930s when construction began on the Daniel Boone Bridge over the Missouri River.

At the turn of the century this part of St. Charles County was isolated from nearby St. Louis by the Missouri River. Three small communities, Hamburg, Howell and Toonerville, were connected to the outside world by the Missouri, Kansas and Texas Railroad, which stopped in Hamburg. In 1937 the Daniel Boone Bridge was completed and suddenly southern St. Charles County had a direct route into St. Louis. It was a project many locals lobbied for, believing it would bring opportunities to the county.

During the Cold War in the late 1950s and early 1960s uranium ore was processed at Weldon Spring and then shipped to other sites to be converted into weapons grade uranium to be used in nuclear weapons.

Instead, it brought the U.S. Army.

“In October of 1940 the townspeople found out, by reading it in newspapers, that the Army was going to take 17,000 acres of land through eminent domain and they had three months to leave their homes and their property forever,” Deyo says.

By early 1940, even before the Japanese attacked Pearl Harbor, it was apparent the United States would eventually be drawn into World War II and the Department of the Army began to prepare. The Army wanted to find an isolated spot with access to a large labor pool where they could build a giant plant to manufacture TNT and DNT explosives.

The area in St. Charles County surrounding the towns of Hamburg, Howell and Toonerville fit the bill. Following an emergency order, more than 500 residents began to move out.

“People were not happy about being pushed from their land, but most knew what they (the government) were doing was right for the country,” says Deyo.

Lillian Yahn grew up in Howell and remembers the turmoil the resettlement caused.
“It was shocking news,” says Yahn, who moved with her family to Troy when the government bought their property. “You can imagine if someone told you, ‘We want your property and you have to be out in two months.’ It would bewilder you. And yet people knew they had to go. When the government said you had to do something, you did it. War was imminent.”

The Army immediately began demolishing and burning hundreds of homes, businesses, churches, schools and any other buildings within the 17,000 acres and within a few months the three towns ceased to exist.

The Weldon Spring Ordnance Works, operated by Atlas Powder Company, began production in 1941 and, at its peak, employed more than 5,000 people and contained more than 1,000 buildings. By the time the plant ceased production on Aug. 15, 1945, the day the Japanese surrendered, it had produced more than 700 million pounds of TNT.

Residents of Hamburg pose for a picture in front of the general store in the small town before it and two other communities ceased to exist. After residents were moved out in 1940 and 1941 the area was converted into the Weldon Spring Ordnance Works.

After the war the Army began selling off pieces of the original 17,000 acres. The Missouri Department of Conservation bought 7,000 acres, with a donation from August Busch, while the University of Missouri bought another 7,000 acres which was later sold to the Conservation Department. These pieces of property are today the Busch Memorial Conservation Area and the Weldon Spring Conservation Area.

The Army kept 2,000 acres and it was there the U.S. Atomic Energy Commission built a uranium ore processing plant in 1955. The Weldon Spring Uranium Feed Mill Plant, operated by Mallinckrodt Chemical Works of St. Louis, did not produce weapons grade uranium, as is often thought, but instead processed raw uranium ore into “yellow cake,” or concentrated ore which was shipped to other sites.

The processing plant operated until 1966. During the Vietnam War the Army planned to use part of the old uranium processing facilities to produce Agent Orange, a herbicide used to defoliate jungle during the war. The Army later abandoned the plan without ever producing the chemical at Weldon Spring. The site, empty and decaying, sat abandoned for more than 20 years, but still contained contaminated equipment and hazardous chemicals.

In the 1980s the U.S. Department of Energy took over the site and began studying ways to clean up hazardous and radioactive waste left there. Waste lagoons on the site contained thousands of gallons of water contaminated with radioactive wastes and heavy industrial metals as well as hundreds of drums, some empty and some filled with unidentified chemicals. A nearby quarry contained hazardous materials dumped there over many years while the abandoned uranium processing plant buildings themselves were widely contaminated.

Next began a long, often controversial process involving the Department of Energy, state and county governments and thousands of area residents that led, in 1992, to an ambitious plan to clean up the Weldon Spring site and move all contaminated materials to a 45-acre site and enclose it in the waste disposal cell designed to safely contain the materials for 1,000 years.

Almost nothing remains of the more than 1,000 buildings constructed in 1940 and 1941 and used to manufacture TNT and DNT explosives for the U.S. Army in World War II. A few concrete bunkers that were used to store explosives can still be found scattered around the August Busch Memorial Conservation Area, which during the war was part of the Weldon Spring Ordnance Works. During the war workers planted grass on top of the bunkers to hide them from the air.

The Weldon Spring site has now come full circle, says Pam Thompson, the former Department of Energy site administrator.

“The project has taken many years but we have been able to clean up a hazardous waste site and create in its place a prairie that’s open to the public and returns a piece of St. Charles County to what it once looked like before European settlement,” says Thompson.

What was once a giant explosives factory covering thousands of acres is now a 200-acre site surrounded by thousands of acres of public land for hunting, fishing, hiking and bicycling. In an odd twist in the story, Deyo says it’s likely that original 17,000 acres of land would have been developed into towns and subdivisions like much of St. Charles County to the north.

“The Weldon Spring Ordnance Works actually made the preservation of thousands of acres of green space possible in St. Charles County,” says Deyo. “I guess if it wasn’t for all that land bought by the Army, it would probably be houses today.”

The Weldon Spring Site Interpretive Center is located on Highway 94 just south of Highway 40. For more information call the center at (636) 300-0012 or visit the Web site

Rural Missouri | June 2020 Issue

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