An evaluation of the results of alluvial groundwater sampling from 1987--1990 at the Durango disposal site

Technical Report · Mon Apr 01 00:00:00 EST 1991

OSTI ID:10134735

This evaluation was conducted to determine if surface discharges of contaminated water from a retention pond and seepage of tailings pore water from the disposal cell have affected ground I water quality in the alluvial deposits east and northeast of the Bodo Canyon disposal cell. The question of whether corrective remedial action is needed for the alluvial groundwater downgradient of the disposal cell is also addressed. Maximum observed concentrations of seven hazardous constituents equalled or exceeded proposed US Environmental Protection Agency (EPA) maximum concentration limits (MCLs) in the alluvial groundwater downgradient of the disposal cell. These constituents include chromium, lead, molybdenum, net gross alpha, radium-226 and -228, selenium, and uranium. Concentrations greater than MCLs for molybdenum, net gross alpha, and radium-226 and -228 may be naturally occurring in the alluvial groundwater. There is no statistical evidence that these hazardous constituents are groundwater contaminants with concentrations that exceed the MCLs in alluvial groundwater. However, the median selenium concentration in monitor well 608 exceeds the MCL. Therefore, selenium contamination in the alluvial groundwater in the area of monitor well 608 is possible. Selenium concentrations show no definite increasing or decreasing trend. Since groundwater contamination by selenium is possible in one monitor well, but concentrations are not increasing, corrective action is not warranted at this time. Alluvial groundwater quality will continue to be monitored quarterly and the discharge from the retention pond should be sampled after treatment to ascertain its potential affects on groundwater quality.

• Research Organization: USDOE Albuquerque Operations Office, NM (United States). Uranium Mill Tailings Remedial Action Project Office
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-91AL62350
• OSTI ID: 10134735
• Report Number(s): DOE/UMTRA-050126-0000; ON: DE93009470
• Resource Relation: Other Information: PBD: Apr 1991
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
54 ENVIRONMENTAL SCIENCES
FEED MATERIALS PLANTS
MILL TAILINGS
STABILIZATION
GROUND WATER
WATER QUALITY
CHROMIUM
ECOLOGICAL CONCENTRATION
LEAD
MOLYBDENUM
RADIUM 226
RADIOECOLOGICAL CONCENTRATION
RADIUM 228
SELENIUM
URANIUM
COLORADO
ALLUVIAL DEPOSITS
CONTAMINATION
PONDS
SAMPLING
COMPILED DATA
054000
540250
540230
540220
HEALTH AND SAFETY
SITE RESOURCE AND USE STUDIES
RADIOACTIVE MATERIALS MONITORING AND TRANSPORT
CHEMICALS MONITORING AND TRANSPORT