For the past seven years, the federal government has been quietly cleaning up unexploded artillery shells and munitions debris in William F. Hayden Green Mountain Park, on the western edge of Lakewood, that date back to World War II.
Soldiers at nearby Camp George West used the north slope of Green Mountain as an artillery range from 1930 to 1945, firing fist-sized 75mm munitions packed with lead balls. But because of poor historical documentation by the Army National Guard, the federal government has no records or maps of these training ranges.
The military history of Green Mountain would have remained buried had it not been for a 2009 grass fire that cleared overgrown brush and exposed these ancient wartime relics. A piece of munitions debris was discovered by a hiker shortly after the fire, which prompted a federal investigation. To date, thirteen unexploded artillery shells and debris from hundreds of munitions have been discovered across 466 acres of parkland.
But it's not just Green Mountain that the government is investigating. More than one hundred Lakewood homes in Mesa View Estates and Green Mountainside are in a "priority 1 zone" for munitions clean up.
"This is an example of how things that used to be out in the middle of nowhere aren't anymore," says Warren Smith, community involvement manager at the Colorado Department of Public Health and Environment, which is overseeing the federal cleanup project. "It's really unlikely that we're going to find something, because the ground would have been disturbed when they built the neighborhoods, when they developed them. There was no record of them finding any munitions when that happened. But on the other hand, they weren't looking for them at that time. ... Forty years, people forget. Thirty to forty years had passed [since the closure of the artillery range] before that area was developed."
Residential cleanup, Smith says, is just a precautionary measure for everyone's peace of mind.
"These are right next to areas where there were impacts, so out of an abundance of caution, it's necessary to get in here even though there's no record of anything going wrong when they were developing the area. No one has ever found anything," Smith says.
The Army National Guard has tried to work with residents the past couple of years with very little momentum. Of the 84 yards it initially surveyed, only ten were ever dug up for potential munitions between 2016 and 2017. No munitions were recovered in any of those circumstances, but one yard did have one piece of debris, Smith says.
Now the federal government is back with new technology, and it's asking residents to give it another chance to complete its cleanup efforts. The first step: getting homeowners to sign right-of-entry agreements to allow investigators onto their property. Residents who signed agreements in previous years are urged to fill out the form again because all agreements on file have already expired or are slated to expire this year.
"We have to have that permission," Smith says. "If someone signs that and then decides they don't want to have digging happen in their yard, that's okay; they can decide that if they choose. We can't compel people to do this. But if they want their yard inspected and investigated, they have to sign."
Previously, the Army National Guard used regular metal detectors to survey yards, which led to tens of thousands of hits for buried metallic objects across those 84 initially surveyed homes. That's because typical metal detectors simply respond to the presence of any metal debris.
New technology will be deployed to neighborhoods this year that can more accurately uncover debris and unexploded artillery shells by determining the size, depth and shape of buried metallic objects. The government first used the technology in 2013 in a two-acre test pilot on Green Mountain; it successfully found nine unexploded munitions. The National Guard is waiting to collect more right-of-entry agreements before setting a timeline on its investigation this year.
"We're not asking people to change their behavior. They can dig in their garden. They can live their lives. They can let their children play in the yard," Smith says.
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If munitions or debris is detected, the National Army Guard will schedule a second visit to dig up the object. Homes within 239 feet of the dig sit would have to be evacuated, and neighbors must voluntarily comply.
Mesa View Estates and Green Mountainside residents looking to confirm whether they are in the Priority 1 zone or would like to agree to a munitions investigation on their property can contact John Haines, a senior program manager with the Army National Guard, at firstname.lastname@example.org or call 703-607-7986.
Green Mountain visitors and area residents should move to safety and immediately call 911 if they encounter a munition.