Hydrogeolic and geochemical studies of selected natural radioisotioes and barium in groundwater in Illinois

Gilkeson, Robert H.; Cartwright, Keros; Cowart, James B.; Holtzman, Richard B.

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https://hdl.handle.net/2142/91633 Copy

Description

Title

Hydrogeolic and geochemical studies of selected natural radioisotioes and barium in groundwater in Illinois

Author(s)

• Gilkeson, Robert H.
• Cartwright, Keros
• Cowart, James B.
• Holtzman, Richard B.

Contributor(s)

• Illinois State Geological Survey
• Florida State University
• Argonne National Laboratory

Issue Date

1983-05-01

Keyword(s)

• Groundwater
• Aquifers
• Water resource development
• Water resource development--Illinois
• Aquifer properties
• Barite
• Barium
• Chemical properties
• Glacial events
• Radium
• Radon
• Sedimentary rocks
• Sulfate
• Uranium
• Thorium

Abstract

Dissolved conentrations of the natural radioisotopes ²²²Rn, ²²⁶Ra, ²²⁸Ra, ²³⁰Th, ²³²Th, ²³⁴U and ²³⁸U and the element Ba²⁺ were investigated in a study of high concentrations of ²²⁶Ra, ²²⁸Ra, and Ba²⁺ in groundwater from the Cambrian and Ordovician bedrock of northern Illinois. The high radium and barium concentrations are naturally present in the major aquifers--the sandstone bedrock; therefore, remedial well construction measures will not lower the concentrations. The combined concentrations of ²²⁶Ra and ²²⁸Ra range from 2.3 to 50.2 pCi/L; the majority of analyses exceed the limit in the drinking water regulations of 5.0 pCi/L. The ²²⁶Ra/²²⁸Ra activity ratio ranges from 0.2 to 41.0; a ²²⁶Ra analysis has no validity for predicting the ²²⁸Ra concentration. Important controls on dissolved ²²⁶Ra concentrations are secondary U on the sandstone matrix and the ionic strength of groundwater. The distribution of accessory minerals that contain ²³²Th is believed to be an important control on dissolved ²²⁸Ra concentrations. Locally the dissolved ²²⁶Ra and ²²⁸Ra concentrations are affected by dissolution-precipitation of secondary barite. Dissolved concentrations of ²²²Rn and U are less than proposed drinking water regulations. The extreme enrichment in the ²³⁴U that occurs widespread in groundwater from the Cambrian and Ordovician bedrock is unique and problematic. The enrichment may reflect recharge of uranium to the bedrock by glacial processes. Dissolved Ba²⁺ concentrations range from <0.01 to 22.4 mg/L. The high Ba²⁺ concentrations occur in groundwater that is depleted in dissolved SO₄²⁻ by anaerobic microbial reactions. A map presents the distribution of Ba²⁺ in groundwater from the Cambrian and Ordovician bedrock in northeastern Illinois.

Publisher

University of Illinois at Urbana-Champaign. Water Resources Center

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/91633

Sponsor(s)/Grant Number(s)

• U.S. Department of the Interior
• U.S. Geological Survey

Copyright and License Information

Copyright 1983 held by the authors

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