To read more about the corrective action that the EPA has taken to clean up the area please visit this link:
http://www.epa.gov/reg3wcmd/ca/va/webpages/vad023741705.html
There is a lot of good info on this page but it's not clear if and when this land could be developed. Honestly, would you buy a house on this property knowing that the ground water and soil was contaminated? I don't care how much you clean up, some of the contaminate will always remain no matter how "safe" the levels are under the EPA's standards.