Although the proposed road’s proximity to the former Rocky Flats federal nuclear weapons manufacturing plant has long been controversial, inspiring numerous lawsuits on environmental grounds, soil samples taken along the proposed alignment last summer revealed levels of plutonium above “actionable levels” established in the facility’s closure plan.

Rocky Flats produced plutonium triggers for nuclear weapons for 40 years until production was halted in 1992. Following a 14-year cleanup operation, most of the 6,200-acre complex converted into a federal wildlife refuge. A small industrial area remains off-limits to the public as a Superfund remediation site.

Broomfield has reportedly contributed $3.4 million to the toll road project’s preliminary phases since 2008. Construction had been scheduled to begin this year.

The move follows a December 2019 decision by one of the project’s three private-sector finalist teams to drop out of the running for the design-build-operate-maintain contract. Jefferson Expressway Group led by ACS, Hochtief, Flatiron, and WSP cited environmental issues and a “sizeable gap” between the project’s anticipated costs and expected toll revenue.

The remaining teams—Jefferson Beltway Connection Partners, led by Kiewit, DIF, and Northleaf; and Colorado Front Range Connectors, led by Shikun & Binui, AECOM, and John Laing—remain in contention for the project.