Project Description: Support
facilities to maintain the mission at Beale AFB have required
them to store and use various fuels and chemicals. At the Capehart
Service Station, several UST's were removed and found to have
leaked petroleum hydrocarbons containing high levels of MTBE
into the surrounding subsurface.
The site is located in the foothills of the Sierra Nevada Mountain
Range, and dense steeply dipping fractured bedrock was found
to have provided complex pathways for the migration of contaminants.
H&A evaluated the site geology and formulated a site-specific
approach to investigate this migration in two phases:
Groundwater Remediation System Following the initial site investigation, H&A designed and
installed a groundwater extraction and treatment system to remediate
perched groundwater located within the former UST pit. Two extraction
wells were fitted with
Grunfos RediFlow 3
submersible pumps that remove contaminants into two
1000-pound Granular Activated Carbon canisters and a 200-pound
fine-grained carbon canister which discharge treated groundwater
to the sanitary sewer system. H&A's quick design and
implementation of the groundwater remediation system allowed
Beale AFB to meet all regulatory requirements while maintaining
the ongoing Base mission without imposed fines or notices of
violation.
Fractured Bedrock Aquifer
Analysis Air and mud rotary drilling technologies were used to collect
continuous rock cores, advance exploratory borings, and install
groundwater monitoring wells to depths as great as 100 feet
in the meta-volcanic rock. Using innovative techniques and applied
sciences,
such geophysical technologies as downhole optical
televiewer and acoustic televiewer image surveys were performed
to measure orientation and degrees of fractures and bedding
planes. Heat-pulse flow meter testing was performed within the
open boreholes to isolate fractures with flowing groundwater.
H&A is continually detailing the site conceptual model to
determine fractures zones preferential pathways for MTBE migration,
and develop an appropriate remedial action for the fractured
bedrock aquifer to prevent degradation to the environment and
protect human health.
For more on fractured rock and the status of this site visit
www.clu-in.org/fracrock,
choose View Site Profile, and then select Beale AFB.
Support
facilities to maintain the mission at Beale AFB have required
them to store and use various fuels and chemicals. At the Capehart
Service Station, several UST's were removed and found to have
leaked petroleum hydrocarbons containing high levels of MTBE
into the surrounding subsurface. 
Following the initial site investigation, H&A designed and
installed a groundwater extraction and treatment system to remediate
perched groundwater located within the former UST pit. Two extraction
wells were fitted with
such geophysical technologies as downhole optical
televiewer and acoustic televiewer image surveys were performed
to measure orientation and degrees of fractures and bedding
planes. Heat-pulse flow meter testing was performed within the
open boreholes to isolate fractures with flowing groundwater.
H&A is continually detailing the site conceptual model to
determine fractures zones preferential pathways for MTBE migration,
and develop an appropriate remedial action for the fractured
bedrock aquifer to prevent degradation to the environment and
protect human health.