Project Number:
DNR-051
Other Project Number:
WR87R006
Funding Year:
1987
Contract Period:
Funding Source:
DNR
Investigator(s) and affiliations:
Gregory Mursky, University of Wisconsin–Milwaukee
Abstract:
Abstract: The total radium content of water produced from the Cambrian, Ordovician sandstone aquifer of southeast Wisconsin is not related to the structure, thickness, or shale content of the formations associated with this aquifer. The total radium content of produced water is also unrelated to the radiometric content of the lower sandstone units within the aquifer.
On the basis of six wells for which complete geophysical logs were available, it was possible to establish a very strong relationship between the radium-228 levels in water from these wells and the thorium-232 content and thickness of the Ordovician dolomite section of the aquifer, Galena-Platteville formations. The correlation coefficient associated with this relationship is 0.97. Using the same six wells it is also possible to establish a very strong correlation, 0.93, between the radium-226 content of produced water and the uranium-238 content and thickness of the upper aquifer sandstone, St. Peter formation. For these six wells, the total radium content of produced water is entirely determined by the dolomite section and the St. Peter sandstone and is completely independent of all other units within the aquifer. In view of the spatial distribution and water quality variations associated with the six study wells, generalization of the results to all of southeastern Wisconsin appears to be reasonable.
The results of this study would not have been possible without the availability of modern geophysical logs and the spectral-gamma log is particularly critical.