Final Remedial Action Completion Report for the ... - Rvaap.org

Remedial Action Completion Report
June 2008
Remediation of Soils and Dry Sediments at RVAAP 08-11 (LLs 1-4)
Page 3-4
information, each sample container was placed in a sealed plastic bag and then placed in an
ice-filled cooler to ensure preservation.
The submersible pump was lowered slowly until it contacted the groundwater surface and then
was continued to be lowered until it reached the midpoint of the well screen. The pump was
turned on and allowed to operate until a steady flow of groundwater was expelled from the
Teflon ® return line at the ground surface. The discharge line was not allowed to touch any
interior portion of the decontaminated sample container or the sample matrix within the
container.
3.2.5 Filtration Procedures
For Shaw groundwater activities, filtered samples were only collected for dissolved TAL metals.
Filtration was performed at each well location using a disposable 0.45-micron (µm) pore size
filter assembly and filters were replaced between each well location or as they became restricted
by solids buildup.
3.2.6 Field Quality Control Sampling Procedures
As part of the groundwater monitoring activities, Shaw collected three types of quality control
(QC) samples consisting of duplicates, equipment rinsate blanks, and trip blanks in accordance
with Section 4.3.7 of the FSAP (SAIC 2001). Duplicate samples of the full suite were collected
at a frequency of 10% of the field samples collected. This sample frequency applies to matrix
spike/matrix spike duplicate (MS/MSD) samples as well. Equipment rinsate blanks were
collected at a frequency of 10% or, depending on the number of samples collected during a day,
one per day per field samples collected at each load line. Temperature and trip blanks consisted
of a sealed container of American Society of Testing and Materials (ASTM) Type I water and
were placed into each cooler used to transport field samples. Trip blanks were analyzed for
VOC analysis.
3.2.7 Decontamination Procedures
Decontamination of equipment associated with the Shaw groundwater sampling activities was
performed in accordance with the procedures presented in Section 4.3.8 of the FSAP (SAIC
2001).
3.2.8 Summary of Groundwater Sample Results
The purpose of the initial groundwater sampling activities was to identify presence of
contaminants in groundwater prior to initiation of Shaw construction activities. Baseline
groundwater sampling was not intended to characterize the extent of contamination at these
locations or attempt to ascertain a potential source. However, in order to establish the existing
contaminant conditions in groundwater at LLs 1-4, where applicable, results were compared to
the United States Environmental Protection Agency (USEPA) Primary Drinking Water
Regulations and their Maximum Contaminant Limits (MCLs) and Secondary Standards, the
USEPA Region 9 Preliminary Remediation Goals (PRGs), and the RVAAP-established
background criteria and summary statistics (inorganics only) for bedrock and unconsolidated
zone filtered/unfiltered groundwater background wells. It should be noted that not all organic
and inorganic compounds, analyzed as part of the baseline groundwater sampling event, have
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