I did a great deal of research on the matter before we felt comfortable buying a home in Leyden Rock. Looking at downwind maps, soil tests, water tests, some early environmental impact statements for the Parkway, results of three cancer studies in the surrounding area and where Leyden Rocks is located I feel very comfortable buying in Leyden Rock.
With Leyden Rock I am more concerned that it is built on top of huge coal mines and part of it is right next to a large dump. Not many studies were done on the impact of the coal mine and the damage left from the mining operations. The dirt was so bad, the developers removed FEET of dirt and brought in new dirt.
Now Cadelas that is another story. That subdivision had too many red flags for me. Do your own research, they are many well written websites for and against building there. You never hear people talking about those subdivision on the east of Indiana for areas south east of Rocky Flats. There are serious down wind concerns for those people.