Could a chemical weapons manufacturing facility be the cause of a slew of earthquakes? According to historical records, the answer is yes. Here’s the story.
Rocky Mountain Arsenal
In 1961 the U.S. Army’s Rocky Mountain Arsenal (located North and East of Denver, Colorado) drilled a 12,000-foot deep well for chemical weapon waste disposal, the idea being that injecting poisonous chemicals deep underground was a “safe” way to get rid of them.
Before waste disposal began, the Army began testing their idea by injecting approximately 568,000 US gallons of city water into the deep well, mostly to make sure their plan was safe. Shortly after these deep underground water injections began in 1961, the City of Denver began to experience a series of minor earthquakes. Considering that Denver does not sit upon any significant Earthquake fault lines, this procedure of injecting water (and later chemicals) into a deep well was widely blamed for causing these earthquakes.
The well caused so much controversy that the Army stopped using it in February 1966 and it was then permanently sealed in 1985.
The Rocky Mountain area has had earthquakes over the years; however, they are normally spread out over long periods of time. This all changed with the new deep well at Rocky Mountain Arsenal. The injection of chemicals began in March 1962 and by the end of the year 190 earthquakes had occurred. Most of these quakes were simply “felt” and did not cause much damage outside of some broken windows.
Unfortunately this trend of minor damage didn’t continue. From January 1963 to August 9, 1967, more than 1,300 earthquakes were recorded. Three 1965 shocks in particular were cause for alarm since they were rated at intensity level six. While a large earthquake in southeast Colorado in October 1966 temporarily drew some of the attention away from the Denver series, a large Denver quake on April 10, 1967 grabbed everyone’s attention.
The 1967 quake was the largest since 1962 and had a 5.0 magnitude. Hundreds of windows were broken, cracks in the asphalt occurred around the metro area, and Boulder area schools were found to have cracked walls. The shock was even felt at the capitol building where legislators ducked for cover for fear of chandeliers falling on them.
It’s generally believed that the water and chemicals injected deep underground “lubricated” existing fault lines and precipitated these Denver-area earthquakes. Seeing as how earthquakes tremors caused a lot of fear and anxiety among Denver residents, the Army stopped injecting chemicals underground shortly after the April quake. However, this didn’t stop the earthquakes.
One last major shock hit the Denver area on August 9, 1967. The 5.3 magnitude tremor caused the most damage, with homeowners across the region finding cracked walls and ceilings, and floors separated from walls. Damage was widespread in this last quake.
The Arsenal Today
Thankfully, the earthquakes associated with the Arsenal have stopped. Today, the area is known as the Rocky Mountain Arsenal National Wildlife Refuge and is home to all kinds of wildlife. The refuge has undergone massive cleanup efforts to restore the area. The area is also known for Dick’s Sporting Goods Park, a soccer-stadium home to the Colorado Rapids of Major League Soccer.
While the arsenal has a storied past among most Denver residents, the restoration of the land for the native wildlife has eased some of the criticisms.
Author John Georgis is an expert on the history of Denver and Boulder. As founder of Banjo Billy’s Bus Tours, John is a treasure-trove of Denver and Boulder trivia and an excellent tour guide. Photo via USFWS Mountain-Prairie