Head to any of the coal burning power plants around the area and look at the fly ash "mountains" built around them. Fly ash has been used in cement, cement block, flow fill, and various other things for many years.
As far as the radioactivity in fly ash. You have been exposed to more radiation to various things in your home and things you eat on a daily basis. Have stone or marble counter tops or tile in your home? Guess what your're living with a radioactive source everyday.....