EPA results for Ohio/PA/NJ drinking water

I was just browsing the EPA test results at Socrata.com:
http://opendata.socrata.com/Government/RadNet-Laboratory-Analysis/cf4r-dfwe

These are just too spotty and inadequate to make much sense of. I imagine that is the intent. Nevertheless, while perusing results via filtering/sorting I noticed that the highest drinking water I-131 samples were from PA, TN, OH, and NJ. I find it interesting that Ohio, PA, and NJ are adjacent states.

Uneven fallout across the US is guaranteed and perhaps this simply relates to the weather patterns and focused deposition in those three states. The are probably plenty of pollution sources in that area too, including nuclear power facilities. I think the North East has many surface water supplies too, perhaps unlike some other areas of the country. Still, I find it somewhat surprising that the hotter spots are there as opposed to the West and NW which we know received some heavy depositions.