FYI, the location near Page Mill Road is where Facebook used to have their headquarters. Stanford did took various remediation measures when they converted the property into faculty housing, but IDK if the FB buildings were adequately protected/ventilated. My understanding is that the vapors are only harmful if they get into buildings and are not adequately ventilated. Stanford put vapor guards under each home they built, among other things.
And an entertaining rant by a UC Berkeley Health Physicist, on D&D (Decontamination & Demolition): http://www.funraniumlabs.com/2019/05/a-stream-of-consciousne...