Rocky Flats National Wildlife Refuge earlier this month opened to hundreds of visitors who came to enjoy the spectacular scenery, wildlife, and recreational opportunities the site offers.
The transformation of this property is a marvel and an achievement to be celebrated.
The refuge is located on lands that once surrounded the Rocky Flats industrial plant, which manufactured components for nuclear weapons. Its opening on Sept. 15 is a result of two phenomena that aren’t always present: a government program that came in under budget, ahead of time, and with bipartisan leadership from elected officials such as Sen. Wayne Allard, Ken Salazar, and Cory Gardner, as well as Govs. Bill Owens and Roy Romer and Congressman Mark Udall.
Rocky Flats is one of the most studied pieces of ground in North America. After its closure in 1989, the industrial plant was the subject of an intensive $7 billion investigation and cleanup, and in 2005, the area surrounding the plant, including the refuge, was determined safe for unrestricted public use. However, when it comes to any claim by government, taking a trust-but-verify approach is warranted, and when it comes to hazardous waste cleanups the better approach is “show me.”
Over the past two and a half decades, soil, air, and water sampling at Rocky Flats has produced literally millions of data points providing information about site conditions.
In the Rocky Flats industrial area — also called the Central Operable Unit — investigations found various contaminants at levels above health-based standards, and those contaminants were thoroughly addressed. That involved removing 21 tons of plutonium and enriched uranium; more than 1.3 million cubic meters of waste and contaminated soils; and 800 structures, including five plutonium facilities and two uranium facilities. It also included three passive groundwater treatment systems, one passive seep treatment system, and two engineered covers over abandoned landfills. To date, more than 16 million gallons of groundwater and seep water have been treated at the site.
These remedies are evaluated regularly and have consistently remained protective of human health and the environment.
The site withstood the 2013 flooding event with only minimal impacts to sampling equipment. Surface water is continuously monitored before leaving the site to ensure it meets radionuclide standards that are far more stringent than federal drinking water standards, although the water is not used for drinking. In addition, 20 years of air sampling at Rocky Flats showed no instances of radionuclides exceeding health-based standards. In fact, the highest air quality value monitored over those 20 years was more than 10 times below the health-based standard.
Many have raised concerns about plutonium exposure and the opening of the refuge. The concern is that walking or biking will cause contaminated soil to be disturbed, resulting in human exposure. This concern ignores that refuge lands were a security buffer for the Rocky Flats plant and were not used for industrial operations. It also ignores years of sampling, monitoring, and investigation that have consistently shown that contaminant levels are very low. In fact, no locations in this area required cleanup. Concentrations are so low that the risk assessment determined the area is suitable for unlimited use, meaning not only is it safe for recreational use, but you could also safely build a house and live there.

We all are exposed to plutonium every day because of deposition from nuclear testing that occurred decades ago. In Colorado, the average background radiation we experience — from all sources — annually is 600 millirem per year. To put that into context for the refuge, if you visited 100 days a year for two and half hours each visit, the residual plutonium would expose you to an additional 0.2 millirem per year.
State and federal agencies have also conducted several studies to assess offsite health effects. The state studied cancer rates in surrounding communities in 1998, 2016, and 2017 and found that rates in those communities were no different than for the remainder of the Denver area. In 2005, the Agency for Toxic Substances and Disease Registry also evaluated the site and could not identify any environmental exposures at levels of public health concern at or near Rocky Flats. More than 20 years of studies show no evidence of increased cancer rates, both before and after cleanup was completed.
There is no health-based reason for not visiting the Rocky Flats National Wildlife Refuge and enjoying all it offers. I look forward to visiting this fall with my family and encourage all to do the same. The refuge is safe for public use and will be a great attraction for those who live in and visit the Front Range for years to come.
Doug Benevent is the Environmental Protection Agency’s Region 8 regional administrator for an area which includes Colorado. He previously worked for Xcel Energy and practiced environmental law at Greenberg Traurig. He was director of environmental programs for the Colorado Department of Public Health and Environment and led the agency from 2002 to 2005, during which time he worked to accelerate the cleanup and closure of the Rocky Flats nuclear weapons facility. Benevento also was on Wayne Allard’s U.S. House and Senate staffs, from 1991 to 1999. During that time, he worked to secure funds and establish the clean-up requirements for the Rocky Flats Plant Superfund site.