The Relation of Radium-226 and 228 to the Groundwater Geochemistry of Carbon, Sulfur, and Chlorine near Michigan's Saginaw Bay

Author

Ray Milejczak

Date of Award

12-1989

Degree Name

Master of Arts

Department

Geological and Environmental Sciences

Department

Geosciences

First Advisor

Dr. Alan E. Kehew

Second Advisor

Dr. Richard Passero

Access Setting

Masters Thesis-Open Access

Abstract

The Michigan Department of Public Health (MDPH) sampled 149 residential wells producing from glacial drift and Saginaw Formation aquifers in Bay, Midland, Saginaw, and Tuscola counties in 1987. These wells were analyzed for ²²⁶Ra, ²²⁸Ra and general chemistry. Of the 149 samples, 50 exceeded the USEPA MCL of 5 pCi/L or greater for combined ²²⁶Ra + ²²⁸Ra activities. A geochemical model (WATEQF, Plummer et al., 1976) was used to determine activity coefficients, activities, ionic strength, and mineral saturation. The radium isotopes were statistically analyzed with respect to the chemical data from MDPH and the geochemical model output. The analysis included the Pearson "r" correlation analysis, linear regression analysis of X-Y plots , and R- Mode factor analysis. ²²⁶Ra and ²²⁸Ra are positively correlated (r = .89) and may be in equilibrium. Also, radium concentrations correlate positively with Na⁺, Ca²⁺, K⁺, Sr²⁺, and Cl^-. Analysis of bedrock cores from Saginaw Formation cores showed ²²⁶Ra, Al₂O³, Na₂O, CaO, and K₂O to be elevated in samples of shale relative to sandstone. The source of radium and the oxides appears to be insoluble clay minerals in the Saginaw Formation. If this is the case, elevated radium, Al³⁺ , Na⁺ , Ca²⁺ , and K⁺ ions in the bedrock and drift aquifers may be derived from deeper strata.

Recommended Citation

Milejczak, Ray, "The Relation of Radium-226 and 228 to the Groundwater Geochemistry of Carbon, Sulfur, and Chlorine near Michigan's Saginaw Bay" (1989). Masters Theses. 4812.
https://scholarworks.wmich.edu/masters_theses/4812