FINAL SAMPLING AND ANALYSIS PLAN - Documents for Moffett Field

WORKSHEET #17: SAMPLING DESIGN AND RATIONALE
Samples collected during this project will include baseline soil/sediment samples collected
prior to construction and confirmation soil, wipe, and sediment samples collected once the
removal action is completed. Details on the sampling design and rationale are presented
below.
Baseline/Pre-Construction Samples:
Pre-construction samples will be collected from soil areas immediately adjacent to Hangar
1 and from the sediment in the stormwater trench/conveyance system around the perimeter
of Hangar 1. The purpose of the pre-construction soil and sediment samples is to establish
baseline concentrations of PCBs, lead, and asbestos. Baseline/pre-construction
concentrations will be compared to confirmation soil samples to verify that contaminants
were not released into the environment as the result of the removal action.
The scope of the soil sampling effort is restricted to the area of the soil immediately
adjacent to (east of) Hangar 1. This area is approximately 21,000 ft 2 . The rationale for
limiting the soil sampling effort to this area is based on the following:
• This is the only unpaved area within the project site.
• Hangar 1 is surrounded by a perimeter storm water collection trench which
prevents surface water from leaving the project site.
• The nearest unpaved area is 300 feet North of Hangar 1.
• Hangar 1 is in an industrial land use area and there are no sensitive habitats nearby
(see Worksheet 10).
Soil samples will be collected from 51 locations from soil areas on the east side of the
Hangar. Sample locations are shown in Figure 11-1. At each location, soil samples will be
collected from 0-6 inches (surface) and 6-12 inches below ground surface (bgs). Surface
samples will be analyzed for PCBs, lead, and asbestos. If the concentration of PCBs in the
surface sample is above 1000 ug/kg, then the 6-12 inch sample will be analyzed for PCBs
to determine the vertical extent of the PCB contamination. Additional samples will be
collected at 6-inch intervals to determine the depth of PCB contamination. Results of
baseline/pre-construction samples will be provided to EPA and Water Board for
consultation and concurrence on areas requiring soil removal if PCB concentrations exceed
1000 ug/kg.
Four baseline/pre-construction sediment samples will also be collected from the
stormwater trench/conveyance system. Locations will be selected based on where there is a
sufficient amount of sediment present for sample collection. Soil and sediment samples
will be collected using the procedure described in Worsheet 14.
Final Sampling and Analysis Plan
Installation Restoration Site 29, Hangar 1
Former Naval Air Station, Moffett Field, Moffett Field,
California
DCN: AMEC-8816-0005-0039
April 2010
Page 17-1