Hydrogeologic investigation, Lawrence Livermore National Laboratory Site 300, Pit 6

Technical Report · Wed Jul 01 04:00:00 EDT 1987

OSTI ID:6025796

A hydrogeologic investigation was conducted at Lawrence Livermore National Laboratory (LLNL) Site 300, Pit 6 to define the hydrogeologic conditions in the shallow aquifer system beneath the Pit 6 inactive landfill and to assess the adequacy of the groundwater monitoring network at the site. Results of the aquifer tests indicate that impermeable claystone strata present beneath the site on the south side of the Carnegie Fault act as a barrier to groundwater flow through the bedrock strata. However, the alluvium overlying the bedrock does provide an avenue for groundwater flow downgradient beneath the site. North of the Carnegie Fault, groundwater is present primarily in the fractured sandstone bedrock. South of the fault, groundwater flow occurs primarily in the alluvial deposits that overly the impermeable claystone bedrock. The direction of groundwater movement beneath the site is toward the south and southeast at a gradient of about 0.011 to 0.024 feet per foot. Laboratory analyses of groundwater samples collected during this investigation did not detect the presence of any chemical constituents that might be present in the groundwater if wastes buried in the Pit 6 landfill were leaking downward into the shallow aquifer system. These analyses, along with those collected during previous investigations, indicate that groundwater quality in the shallow aquifer system has not been adversely affected by the materials buried in the disposal trenches at the site. Continued groundwater monitoring in the vicinity of Pit 6 should be conducted to detect potential leakage from the disposal trenches.

• Research Organization: Brown and Caldwell, Pleasant Hill, CA (USA); Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6025796
• Report Number(s): UCRL-15915; ON: DE87014243
• Country of Publication: United States
• Language: English

Related Subjects

520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
520500* -- Environment
Aquatic-- Site Resource & Use Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
AQUIFERS
ENVIRONMENTAL QUALITY
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GROUND WATER
HYDROGEN COMPOUNDS
HYDROLOGY
LAWRENCE LIVERMORE LABORATORY
MANAGEMENT
NATIONAL ORGANIZATIONS
OXYGEN COMPOUNDS
SANITARY LANDFILLS
US AEC
US DOE
US ERDA
US ORGANIZATIONS
WASTE DISPOSAL
WASTE MANAGEMENT
WATER
WATER QUALITY
WATER WELLS
WELLS