But other radioactive elements present in the landfill were tightly controlled by the federal government and typically associated with nuclear-weapons production or commercial nuclear reactors. Radiochemical analyses performed for both the EPA and the Lowry Coalition indicated the presence of five different isotopes of plutonium, as well as americium-241, a contaminant that is often found in weapons-grade plutonium. Numerous other radionuclides created in nuclear reactions or atomic-bomb detonations, including strontium and cesium, were also detected.
In a memo dated July 19, 1990, a CH2M Hill official recommended that additional safety precautions be taken in the field because of the high levels of tritium and plutonium-241 being detected. Although the company was careful to emphasize that the radiation findings had not been confirmed, it nonetheless advised that a panoply of protective measures be implemented, including baseline and exit urine samples from on-site workers, periodic monitoring at the landfill, the use of dosimeter badges, and a four-hour course in basic radiation-safety techniques that would include a refresher in the operation of portable survey counters.
CH2M Hill, a global engineering and consulting firm, had developed considerable expertise in radioactive waste during its work not just for the EPA, but also for the U.S. Department of Energy and the Department of Defense. In four years, it would form a joint venture with Virginia-based ICF Kaiser; the resulting company, Kaiser-Hill, would successfully bid for one of the largest cleanup contracts ever awarded by the Department of Energy.
The job? Cleaning up Rocky Flats. Between 1995 and 1999, Kaiser-Hill received $2.9 billion in basic costs, according to the General Accounting Office. If all goes well, by 2006 the company stands to earn another $4 billion in cleanup costs and anywhere from $130 million to $460 million in incentive fees for its work at the former nuclear-weapons plant.
At Lowry, CH2M Hill was finding tritium concentrations as high as 2,200 picocuries and plutonium-241 in amounts ranging up to 150 picocuries. The Lowry Coalition, using its own independent laboratory, was seeing the same kinds of readings for plutonium-241 and encountering tritium levels as high as 4,000 picocuries. These levels greatly exceeded the background radiation that could be expected from fallout as a result of aboveground nuclear detonations in the '50s and '60s.
A worried CH2M Hill official pointed out that background levels for plutonium-241 should have been less than 1 picocurie and tritium concentrations should not have exceeded about 200 picocuries. (A picocurie, which is a trillionth of a curie, is too small to be seen with the naked eye; it represents 2.2 "disintegrations," or energy releases, per second.)
Both tritium and plutonium-241 were present at Rocky Flats. But Rocky Flats and two of its private contractors, Dow Chemical and Rockwell International, have denied sending any radioactive waste to Lowry. Although records maintained by Waste Transport and other haulers show that cutting oils, solvents, paint thinners and other materials from the plant were dumped at Lowry, Rocky Flats officials have steadfastly maintained that these materials were not contaminated. To this day, the source of these radionuclides and dozens of others remains unexplained.
Tritium, a radioactive isotope of hydrogen, is used primarily to boost the yields of both atomic and hydrogen bombs and is frequently housed in removable containers located in the warheads themselves. At Rocky Flats, tritium was occasionally released into the environment when contaminated weapons components were disassembled or plutonium was being reprocessed. Health physicist Edward Putzier, a longtime Rocky Flats scientist, wrote in a 1982 paper that some glove boxes contained "massive amounts" of tritium.
Plutonium-241, the other radioactive isotope detected at Lowry, is found in both weapons-grade plutonium and the plutonium created in nuclear reactors. It transforms itself in 14.4 years to a more stable isotope, americium-241, by emitting a beta particle, or high-speed electron. Americium then sticks around in the environment for another 433 years. Americium builds up as the plutonium-241 decays; the "older" the plutonium, the more likely it is to contain more americium.
It so happened that the wells at Lowry were also found to be contaminated with americium-241. The americium does not appear to have been restricted to any one particular part of the landfill; rather, it was scattered throughout the waste pits, in the groundwater and along the western and southern boundaries of the site, where patrolman Bill Wilson once saw tankers emptying their loads.
From the moment Rocky Flats opened its doors, americium proved to be a problematic contaminant. It arrived there in one of two ways: in the "feed" plutonium that was shipped under guard to Rocky Flats from the vast production facilities in eastern Washington State or South Carolina, or in the "site returns" -- the aging plutonium pits that were removed from warheads and sent back to Rocky Flats for reprocessing.