Hydrogeology of the Dakota Group aquifer with emphasis on the radium-226 content of its contained ground water, Canon City Embayment, Fremont and Pueblo Counties, Colorado

Technical Report · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6433140

Vinckier, T A

The Dakota Group aquifer of the Canon City embayment comprises two primary water-bearing units, the Lytle Sandstone Member at the base and the Dakota Sandstone at the top, separated by the semiconfining, arenaceous Glencairn Shale Member. The ground water in this area probably represents a mixture of some or all of the following genetic types: (1) ground water connate to the Dakota Group; (2) ground water, connate or otherwise, entering the aquifer as leakage from adjacent semiconfining strata; (3) deeply circulated meteoric ground water; and (4) hydrothermal fluids (magmatic or metamorphic ground water) purged from the crystalline basement complex underlying the embayment. The contents of the radium-226 in ground water from 117 wells completed in part or all of the Dakota Group were determined by the dissolved radon-222 emanation method. Sixty-seven percent of the ground water samples have radium-226 activities greater than 5.0 picocuries per liter of water (5.0 pCi/1), the recommended maximum permissible concentration of radium-226 in drinking water established by the Environmental Protection Agency in 1973. Inspection of gamma-ray logs of about 20 wells revealed the presence of moderate to extremely high gamma radiation in strata of the Dakota Group, the Morrison Formation, the Fountain Formation, and in the crystalline basement rocks. High levels of radium-226 in drinking water supplies pose potentially serious health hazards to the users. Owners of wells producing such water supplies are advised to (1) install, at the homesite, ion exchange (filtering units) capable of removing /sup 226/Ra/sup 2 +/ ions and other aqueous radium species from the water or (2) effectively case out those stratigraphic intervals in the bore hole showing high gamma radiation preventing possible radium-rich ground water within these intervals from entering the well.

• Research Organization: Colorado Geological Survey, Denver (USA)
• OSTI ID: 6433140
• Report Number(s): USGS-OFR-82-3; ON: DE83901638
• Country of Publication: United States
• Language: English

Related Subjects

520301* -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- Water-- (1987)
54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
580100 -- Geology & Hydrology-- (-1989)
ALKALINE EARTH ISOTOPES
ALPHA DECAY RADIOISOTOPES
AQUIFERS
CHEMISTRY
COLORADO
DRINKING WATER
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL QUALITY
EVEN-EVEN NUCLEI
FEDERAL REGION VIII
GEOLOGY
GROUND WATER
HAZARDS
HEALTH HAZARDS
HEAVY NUCLEI
HUMAN POPULATIONS
HYDROGEN COMPOUNDS
HYDROLOGY
ISOTOPES
NATURAL RADIOACTIVITY
NORTH AMERICA
NUCLEI
OXYGEN COMPOUNDS
POPULATIONS
RADIATION HAZARDS
RADIOACTIVITY
RADIOECOLOGICAL CONCENTRATION
RADIOISOTOPES
RADIUM 226
RADIUM ISOTOPES
STRATIGRAPHY
USA
WATER
WATER CHEMISTRY
WATER QUALITY
YEARS LIVING RADIOISOTOPES