When We Are History

Steve McCracken has overseen a 13-year, $800 million cleanup and burial of the radioactive waste at Weldon Spring. Now that the odyssey is nearing its end, one thought haunts him -- how to warn people in the future not to dig it up.

There were a lot of unknowns. But once the PCBs or mercury or tributyl phosphate or uranium or standard solvents were identified, they were transferred to new containers, labeled and lined up in a temporary storage area. Then the heavy equipment was brought in to dig up and bulldoze the 3,385 cubic yards of waste-pit debris. This material, including processing and construction equipment, empty drums, piping and concrete blocks, was then cut, split, crushed, sheared and stored near the newly labeled drums in a temporary storage area. The place slowly started taking on the attributes of a large discount warehouse, with its aisles sectioned off into rows of metal pieces, concrete material or drums labeled "reactive metals," "waste oils," "nonflammable organics" and the like.

Everything, though, was temporary, because the DOE was still studying whether the contaminated materials and water should be treated at the project and whether, once treated, they should be stored on-site; or buried in some remote subterranean salt mine; or dumped in the middle of the ocean, Soviet-style; or shipped Federal Express to another planet.

Meanwhile, south of the site at the quarry, workers began planning on hauling out the 120,000 cubic yards of soil, structural debris, drums and concrete. To do that, though, meant first pumping out 3 million gallons of water, building a facility to treat the water and then constructing a special haul road between the quarry and the chemical-plant site, so the hazardous debris pulled out of the quarry wouldn't have to travel on Highway 94.

For McCracken, this would prove the most controversial part of the entire cleanup project, because the idea was to treat the quarry water, contaminated with TNT, uranium, radium, arsenic, cyanide and thorium, then release it directly into the nearby Missouri River, which provided drinking water to about 1.4 million people downstream in St. Louis County.

Reports were written, public meetings were held, and the residents of St. Charles County soon learned more about waste-water treatment than they probably ever wanted to know.

In the purification process used at Weldon Spring, contaminated water is sent through an elaborate series of treatments, each designed to remove specific toxins. The first step is to funnel the water into a tank, where lime is added, forcing metals dissolved in the water to clump up and fall out as a solid. This removes almost 95 percent of the metals, like uranium, in the water.

Then the water is funneled onto the clarifier, where additional solids such as iron, arsenic and manganese drop to the bottom of the tank and fall through to a filter press, where a small-pore filter cloth squeezes out excess moisture, yielding a solid "filter cake," which is then stored. The excess moisture from the filter cake is redirected back through the system.

Meanwhile, the water remaining on top of the clarifier is channeled to a multimedia filter, where anthracite coal and fine sand remove any smaller solids that don't drop to the bottom of the clarifier. From there, the water speeds to activated alumina, where arsenic and fluoride are removed, and from there through a tank of activated carbon to eliminate any remaining organic contaminants such as TNT. The final step, the ion exchange, takes out any last traces of uranium.

Usually water like this is treated, released and tested periodically for safety. But to ease residents' concerns about potential glitches in the process, the DOE created a special system wherein treated water flows into one of two million-gallon effluent ponds. When the first pond is filled (after about nine days of flow), treated water is directed into the second pond, while testing of the water in the first pond takes place. Before discharge, the water is tested for any traces of the substances in the toxic stew, including arsenic, mercury, 2,4-dinitrotoluene, asbestos, gross alpha radioactivity, radium-226, radium-228, suspended solids, chromium, selenium, fluoride, gross beta radioactivity, thorium-230, lead, manganese, cyanide, sulfate, chloride, uranium and thorium-232.

Residents in St. Charles County signed onto the plan, but those in St. Louis took numbers and lined up to complain. It was now 1990, and Kay Drey, a seasoned environmental advocate from the St. Louis area -- who can recite the decay rate of polonium-210 by heart -- remembers well what went through her mind when she first heard of the DOE's plans.

"When I heard about the quarry water being released into the river, some of us said, 'Well at least put it into tanks and store it until you can figure out a way to make it pure before putting it into the river nine miles upstream from St. Louis' water intake,'" Drey says. "And when they seemed absolutely determined to put it into the river anyway, they brought in the idea of a water-treatment plant, and that introduced a whole new set of problems. They never even built a pilot plant to test it out first, and every engineer I talked to said that was outrageous."

Drey's fears were compounded when she became suspicious that certain materials were not being detected by the system's monitors. "I have no confidence in the system. There were, and still are, a lot of unanswered questions."

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