By Will Grandbois
On a high flank of Battlement Mesa, a summer home sat almost atop a nuclear test site, and fish occupied a former drilling fluid overflow pond.
That’s how the U.S. Department of Energy described the scene in 2005, when it released an “End State Vision” report on cleanup from Project Rulison decades before.
It all started with the U.S. Atomic Energy Commission’s Operation Plowshare, which aimed to find peacetime applications for nuclear explosives.
“The naive assumption was that, since other explosives have industrial uses, so should nuclear devices,” explained Rick Aster, Geosciences Department head at Colorado State University. “Even at its inception, there were concerns about many aspects of the program.”
After several proposed projects involved excavation on a grand scale — fit for artificial harbors or sea-level canals — scientists shifted their sights to western Colorado with something else in mind: natural gas.
It seems almost reasonable in a declassified film on the subject released in 1969, two years after the initial test in New Mexico. Over grainy footage of Parachute — then Grand Valley — about eight miles from the site, a trustworthy-sounding announcer informs viewers that the process is hoped to be “far cheaper and a great deal more efficient” than other proposed methods of the era, and that by alternating backfill density, “underground containment of gases developed during the nuclear explosion can be assured.”
The actual detonation of a 40-kiloton nuclear device — more than twice the potency of the bomb dropped on Hiroshima — occurred on Sept. 10, 1969, 8,426 feet underground, well below the area’s water table.
As expected, the majority of the radioactivity was confined to a pool of nuclear glass at the bottom of the resulting chamber — but the natural gas released proved too radioactive for use, and also less plentiful than expected.
Project Rio Blanco, conducted in 1973 around 38 miles northwest of Rifle, was equally unsuccessful.
“This early attempt at large-scale fracking was a very expensive failure,” Aster observed.
By the end of 1976, facilities and equipment were dismantled and removed and the surface decontaminated. Meanwhile, the government monitored the area for contamination.
According to a fact sheet assembled by the Department of Energy’s Legacy Management in 2015, no such evidence ever surfaced.
“After eight consecutive quarters of sampling in 1996 and 1997, no migration of petroleum hydrocarbons above risk-based trigger levels was detected,” it reads. “The geologic formations between the near-surface aquifers and the deep, subsurface detonation point are nearly impermeable and produce little or no water. ... No radioactive contamination associated with the Rulison test has been detected in any samples taken from the nearby municipal drinking water supply springs, the water supply wells on five local ranches, or the spring and three wells on the test site.”
Although there are no plans to remove the underground contamination, “because no feasible technology for removal currently exists,” Legacy Management asserted its commitment to “long-term monitoring of wells for potential contaminants and the protection of human health and the environment.”
The fact sheet also acknowledges that the proliferation of drilling in the area in recent years.
“Technological advancements in hydrofracturing ... have raised concerns that fractures might eventually extend into radioactive contamination from the detonation and bring contaminants to the surface through produced gas and water from the wells.”
Although numerous long-lived radioactive elements are believed to be trapped at the site of the explosion, one of the biggest concerns is tritium, a radioactive form of hydrogen with a short half life but the potential to travel.
Researchers at Nevada’s Desert Research Institute and the S.M. Stoller Corp. in Grand Junction ran a series of models for tritium spread at the site in 2007.
“The main findings were that tritium is likely to be confined within lot 11, which is the geographic unit in which DOE-OLM has an institutional control, and that during the 30-year period of gas production, tritium reached the production well in fewer than 5 percent of the computer simulations,” read a 2009 addendum to the study. “In the few realizations in which tritium reached the hypothetical well, the peak concentration of gas reaching the production interval was of low enough concentration that it is likely to be of no risk to human health and the environment.”
Still, all drilling below 6,000 feet is barred within the 40 acres around ground zero, and any permits within 3 miles are subject to approval by the Department of Energy.
“I would be very surprised if any wells in the area were ever approved,” Aster said.
Although the health risks are minimal as things stand, he said, his advice for the future was straightforward: “Do not disturb.”