Radon Surveys Appendix 1988-1993
The counties that comprise geological regions were determined by the North Dakota Geological Survey in September 1987. Factors considered were geological factors, soil permeability, and NURE data. NURE data were the results of a Statewide test for uranium using an airplane flyover which canvassed the State and gathered data. The results are averaged and the counties are rated as low potential for radon (Region 3), moderate potential for radon (Region 2), and high potential for radon (Region 1).
Geological Region 1
The counties of Adams, Billings, Bowman, Grant, Hettinger, Morton, Oliver, Pembina, Slope, and Stark comprise Geological Region 1. The population of the region is 73,930, 11.6% of the State's population. All the counties, except Pembina, are located in the southwestern part of the State. Pembina is the northeast most county in the State.
Geological Region 2
Geological Region 2 is comprised of the counties of: Barnes, Bottineau, Cass, Dunn, Emmons, Golden Valley, Grand Forks, Kidder, Logan, McHenry, McKenzie, Mercer, Pierce, Richland, Rolette, Sargent, Sioux, Steele, Towner, and Traill. The population of the region, 291,835, is 45.8% of the State's population. The counties, generally, form a T through the middle of the State and follow along the eastern boundary.
Geological Region 3
The population for Geological Region 3 is 271,735, 42.6% of the State's population. For more on population, see Table 18. The counties that comprise Region 3 are Benson, Burke, Burleigh, Cavalier, Dickey, Divide, Eddy, Foster, Griggs, Lamoure, McIntosh, McLean, Mountrail, Nelson, Ramsey, Ransom, Renville, Sheridan, Stutsman, Walsh, Ward, Wells, and Williams.