It's a common concern expressed among natives to Colorado, and particularly west Arvada. The former site of the Rocky Flats nuclear weapons manufacturing facility, infamous for being the site of the costliest cleanup in American history, is directly to the north of Candelas - now set aside as a 5,237 acre wildlife refuge. Fears are not helped by hysterical website articles proclaiming the possibility of contamination in the soil of neighboring new developments (without any factual, scientific evidence to support it).
I grew up near the southwest corner of Stanley Lake, southeast of Rocky Flats. I spent the better part of three decades there, prior to making the move to Los Angeles to become a video editor in Hollywood. At 46 years of age as of this writing, I'm also cancer-free. As is my family, and the families we grew up with, in the neighborhood. Cattle were raised and grazed in the fields to the west of the house (which is now occupied by the Five Parks development). Rocky Flats was only ever a concern as a potential target for foreign invaders or bombers, for us.
Scientifically-speaking, the land that Candelas now occupies has been independently verified as being safe for building and living on by CTL Thompson, Inc. Click here for their independent 2013 report, expressing the belief that the land was safe for residential development.
To hear many people tell it, building on the land that Candelas currently occupies is worse than putting your house on an ancient American Indian burial ground...and that's simply not true. There aren't spent plutonium rods mere feet beneath your new home, in fact the levels of radioactive material in the soil are unremarkable, and not potentially harmful to humans.
Not satisfied with the information that had been made available publicly, David Wood (a retired physics professor who was considering a home in Candelas) decided to take matters into his own hands. He took three soil samples from the backyard of the lot he was considering and had the State Health Department analyze them. The findings? "They came back with no plutonium at all." He then bought a Geiger counter and did his own readings, finding that the results were consistent with the background radiation seen all over Colorado.
What most people don't realize is that virtually all soil contains radioactive elements...they are just considered "background" radiation that is not harmful to humans or animals. Any damage done is repaired almost immediately by our bodies. Colorado actually has higher levels of background radiation compared to coastal cities, due to the altitude and the increase in ground radiation from uranium. That hasn't stopped the massive influx of new residents from both coasts, though!
In short, the fears about buying a home and putting down roots in the beautiful and constantly-expanding developments of Candelas and Leyden Rock are about as scientifically-founded as worrying that the Candyman will come and get you, if you say his name in a mirror three times. I recommend that everyone who is looking at these beautiful areas, with their fantastic view of the foothills and proximity to the best of everything that Colorado has to offer, simply look at the science. Not the conjecture, not the unfounded fears...the facts. The fact is, West Arvada is one of the best places in Colorado to live and that is why it's my favorite area to talk about and show people, in my real estate business.
Rocky Flats Stirs Strong Emotions,Pits Sides 10 Years After Cleanup (Denver Post)