Westminster is making it clear the city doesn’t want to increase access to hikers and cyclists visiting the Rocky Flats National Wildlife Refuge — the one-time site of a Cold War nuclear weapons plant that continues to spark health worries 30 years after it closed. The city last week became the second community surrounding the 6,200-acre federal property to withdraw from an intergovernmental agreement supporting construction of a tunnel and bridge into the refuge, home to more than 200 wildlife species, including prairie falcons, deer, elk, coyotes and songbirds. Broomfield exited the $4.7 million Federal Lands Access Program agreement four years ago, and both cities point to potential threats to public health from residual contamination at the site — most notably the plutonium that was used in nuclear warhead production over four decades — for their withdrawal. “I think we have a moral obligation to get out of this,” Westminster Councilman Obi Ezeadi said during a meeting Monday night. Westminster’s withdrawal comes less than a month after a federal judge denied several environmental organizations a preliminary injunction that would have stopped the project cold.