Great journalistic work! I am an environmental soil scientist.I just read your blog. There is alot going on here!I was involved in some cleanup work at a small lumber mill in Arcata and some pulp mills back in the midwest including a huge Superfund Site at Kalamazoo River.
Anyway, you are totally right, the way to get this thing cleaned up is to have soil and water testing done. That is the only way to prove residual contamination. Unfortuantely the Clean ir and Clean Water Acts are shell and do not prevent or fine essentially any polluters. This is a huge issue nationwide! That infomation will likely go on deaf ears; especially if the facility is not in operation.
I am surprised that the new owner, when purchasing the land, did not conduct due diligence in order to protect himself from liability. That means that he would have likely either done some soil/groundwater sampling, or got some sort of buy-off from agencies that he isn't responsible for residual contamination (virtually impossible and usually only done if the city inherits the property). Maybe this is why the deal fell through because he didn't weant the liability???
The goal it seems is that you think there is residual soil and groundwater contamination. Am I correct? If so, you have a good chance of getting support and funding, especially if you have a potential viable business that wants to operate there.
There are 2 routes I would recommend
1) collect soil/groundwater/surface water samples from nearby residents, get them anaylzed, and (assuming results are elevated to be a threat to human health or the environment, submit the results to your congress representatives, EPA, local health department, and news agencies simultaneously.
Second route, if there are low levels of contamination, even at the facility, try to talk to someone at the city who will apply for a targeted brownfields assessment grant. This is $50,000 for free that is given to municipalities with little to no strings/grant proposal to conduct a soil and groundwater assessment at the facility. If anything results from that, you have a foothold into either action against the facility, EPA cleanup, or additional grants for cleanup. This can be complicated if the landowner is fighting you.
Anyway, this is very basic but I would be more than willing to help in wahtever capacity I can. Send me an e-mail if you have any questions and good on you for fighting for the health of your community!!