Transformer oil, up until the 80's had PCB's in it. There were entire neighborhoods fenced off and the government bought the property because the PCB's were carcinogenic (causes cancer). There were numerous class action lawsuits filed, but the families involved barely got any of the "billions" of dollars the courts awarded. The "LAWYERS" got the lions share of the money. There was a place south of Houston that this happened to, it was called the BRIO dump site. It and the neigborhood that was built on top of it was fenced of and the property was bought by the Feds. It took years to clean it up and the lives lost were never publicized.