Colorado transforms former weapons site into thriving 15,000-acre urban wildlife refuge

In the early 1940s the US Army selected roughly 17,000 acres of Commerce City farmland for manufacturing chemical weapons and rocket fuel, and from the 1950s to the 1980s Shell operated pesticide plants on the same ground. The resulting pollution, including more than 600 identified chemicals and several large spills, contaminated soil and groundwater, earning the site a place on the Superfund National Priorities List in 1987.

A $2.1 billion cleanup spanning 15 years removed contaminated soil to depths of up to 10 feet, installed engineered caps, and treated polluted groundwater, after which Congress designated the area a national wildlife refuge in 1992. Today the 15,000-acre Rocky Mountain Arsenal National Wildlife Refuge supports over 330 species, including reintroduced black-footed ferrets, and attracts nearly 500,000 visitors each year. Approximately 1,000 acres remain under US Army management for waste and water-treatment facilities, while nearby Commerce City has invested more than $120 million in public amenities such as open space, a civic centre, a high school and a soccer complex.