Bechtel Jacobs was contracted to dismantle and demolish the K-25 facility in September 2008. The contract, valued at $1.48 billion, was made retrospective to October 2007, and ended in August 2011. Since then demolition work has been carried out by DOE's current environmental management contractor, URS | CH2M Hill Oak Ridge (UCOR). Demolition of the K-25 facility was expected to be completed by July 2014. By 23 January 2013, demolition of the north and west wings was complete, with only a small portion of the east wing remaining (6 units out of 24 on the east wing). The final section of the east wing was brought down on 19 December 2013. The last debris was removed in 2014. Demolition of K-27, the last of the five gaseous diffusion facilities at Oak Ridge, began in February 2016. US Senator Lamar Alexander and US Congressman Chuck Fleischmann joined 1,500 workers to watch the final wall come down on 30 August 2016. Its demolition was completed on 28 February 2017.