SIGN NOTHING FROM THE RAILROAD OR GOVT WITHOUT A LAWYER SEEING THE DOCUMENT FIRST. IF THE DOCUMENT SAYS IT IS FOR "HELP", THAT WILL BE ENTICING TO SIGN ASAP - DON'T. I CANNOT EXPRESS THAT ENOUGH.
Unfortunately, my family has been touched by contamination twice in my life:
1. Leaks from a nuclear weapons facility, which eventually killed my dad. I don't say that as a claim or assumption as we were paid off by the Feds when he died. Just the water in the area was dubbed the single greatest environmental hazard at any of its nuclear facilities by the Department of Energy. The issues, the cover-ups & the raid by the FBI at this facility is well publicly documented: Rocky Flats Plant
2. My current home
My home's soil is permanently contaminated from a lead leak from a smelter that was caught in 2001 by regulators when they tested the ground & eventually the BLOOD of local children... to be honest, I still do not drink/cook with the water. The water tastes horrible & city hall cannot give us a definitive answer WHY they add a significant amount of chlorine to our water 2-3 times a year - the chlorine in the water is so strong that you can OBVIOUSLY smell it & it STAINS red-ish the toilets, bottom of the shower & sometimes the sinks. They have "remediated" - they remove the top 12" of the soil & replace it - the soil around our house several times as the lead makes it's way up to the surface.
Due to these experiences... I cannot legally suggest anything but I will tell you what I would do.
I WOULD...
In my opinion, since the railroad has personally hired security to protect the area & their own testing crew, something fishy is going on & a huge possibility of a cover-up. I'd be VERY surprised if the railroad doesn't start paying people for their properties & start to demolition homes.
I feel for your community & pray that you don't just get answers but PAID for your property, belongings & hassle to move.