April 2004 - Simi Valley City Council approves 461-home Runkle Ranch development after receiving a positive environmental impact report.

Oct. 2006 - Developer voluntarily halts grading at the site due to concerns of nearby residents regarding possible contamination in Runkle Canyon related to operations at the nearby Santa Susana Field Lab.

July 2007 - City of Simi Valley conducts its own set of tests in response to sampling done by citizen activist group calling themsleves Radiation Rangers. City says its limited results found the area poses no immediate threat to the public.

Oct. 2007 - City asks state’s Department of Toxic Substances Control to provide scientific opinion about Runkle Canyon.

Nov. 2007 - City receives letter from DTSC stating they’ve asked builder KB Home to enter into voluntary agreement giving DTSC authority to oversee any cleanup in the canyon.

April 2008 - Runkle Canyon LLC—a joint partnership between home builders KB Home and Lennar—sign agreement with DTSC requiring them to submit documentation summarizing previous investigations that occurred at the site between 1999 and 2007.

Nov. 2008 - DTSC tells the City Council it will have a final answer regarding the safety of the site by summer 2009.

Jan. 2009 - Draft response plan submitted by developer comes under fire from residents and nuclear activists.