Table_4-1_Landscape.pdf

TABLE 4-1. SAMPLE NUMBERS, LOCATIONS AND RATIONALE

Location Analytical Method

Depth (inches) Proposed Samples Rationale

Perimeter Area– South (Figure 7)

8082 - Aroclors 0-3 17 samples Initial characterization of this portion of adjacent property;

previously unsampled.

Perimeter Area– Southwest (Figure 7)

8082 - Aroclors 0-3 12 samples (11 surface and 1 subsurface) Assess extent of previous sample results greater than 0.23 mg/kg.

Perimeter Area– North (Figure 8)

8082 - Aroclors

0-3 and 3-12

20 samples (18 surface and 2 subsurface) within Perimeter Area– North

These locations were not sampled previously due to inaccessibility from thick vegetation.

East of Perimeter Area–North (Figure 8)

8082 - Aroclors 0-3 5 samples just east of Perimeter Area–

North Samples will address coverage on the eastern edge of the exposure area along the railroad right-of-way.

Perimeter Area– North and Perimeter Area– East (Figure 8)

8082 - Aroclors 1668

- Congeners

0-3

5 samples in B12, B14, C7, C11, and D16; samples should be collected in areas of full sun, as close as practical to previous elevated PCB concentrations

The PCBs have likely weathered over time. These samples shall be analyzed for both Aroclor and congeners. These locations were chosen as they are located offsite, have some of the higher concentrations from previous offsite sampling (1.4 mg/kg, 8.5 mg/kg, 9 mg/kg, 12 mg/kg and 34 mg/kg), and are in an area that may have collected surface water runoff.

Onsite northeast corner (Figure 8)

8082 - Aroclors

0-3 and 3-12

28 samples (23 surface and 5 subsurface) from D11 to D15, E12 to E15

Samples will address coverage in the maintenance yard NE corner. Elevated concentrations previously were found along the eastern and northern borders in the surface and shallow subsurface.

Onsite former Transformer Areas 1 and 2 (Figures 9 and 10)

8082 - Aroclors

0-3 and 3-12

47 samples (42 surface and 5 subsurface) in and around former Transformer Areas 1 and 2

Sample locations are based on previous PCB concentrations 10 mg/kg or greater inside the maintenance yard.

Additional samples will bound these locations for remediation area assessment.

Maintenance yard between AOCs 1–3 and the perimeter (Figure 10)

8082 - Aroclors 0-3

17 samples in the area between the edge of former Transformer Area 2 and the perimeter

Samples will provide coverage between AOCs 1–3 and the property perimeter.

PCB AOC2 8015M - TPH 0-6 16 samples in PCB AOC2 For TPH analysis of samples in PCB area.

TPH/PCB AOC2 8015M - TPH 10 ft intervals 39 samples in 3 soil borings For TPH analysis of soil samples with depth.

TPH/PCB AOC2

8015M - TPH,

8082 - Aroclors, 8270 - PAHs

Ground-water

1 sample per boring (maximum 3 samples) For TPH, PCB, and PAH analysis of groundwater, if present.

Table 4-1. Sample Numbers, Locations and Rationale