Selection of Sampling Locations. The objective of the second phase soil sampling plan was the collection of samples that would identify the potential contaminants present throughout the site's surface soils (panhandle, mound, and non-refuse fill areas) and in the subsurface soils of the non-refuse fill area. 115 The method chosen for selecting sample locations combined both systematic and random sampling techniques. The entire 85-acre site was divided into 20 blocks of equal size (500 ft by 500 ft). Each block was them further divided into four equal quadrants (250 ft by 250 ft). The quadrants were labeled A,B,C, and D in each block. Sample locations were chosen by generating random numbers for use as distances along the X and Y axes for each block. Coordinates were generated until a sample site was randomly selected from each of the 80 quadrants. The distances were measured from the south corner of each block. In this manner, four soil sample locations, one from each quadrant, were selected for each block. However, if the quadrant extended into the Belmont Slough, the quadrant was omitted from the random selection process. The blocks, quadrants, and sample locations are indicated in Figure 4. Table 5 contains the sample site coordinates for the surface samples; Table 6 identifies the blocks and quadrants for which the subsurface samples were collected. Surface samples from each available quadrant consisted of the top 6 inches of soil. Samples from the four quadrants were composited by the analytical laboratory prior to analysis, such that a single analytic result is reported for each of the twenty blocks. As previously explained, the number of available on-site quadrants varied. Twelve of the twenty blocks had samples from all four quadrants; two blocks had samples from three quadrants; five blocks had samples from two quadrants; and, one block had a single sample. Therefore, a total of 65 on-site surface samples were collected. The ten, second-phase, subsurface soil samples were collected from blocks 11 through 20, which are located in the non-refuse fill area. One randomly selected quadrant was sampled for each of the ten blocks. The quadrant coordinates for each subsurface sample site were the same as those used for that quadrant's surface sample site. The subsurface samples were collected in the unsaturated zone at a depth range of 2 to 116 Figure 4: [MAP OF SITE PLAN WITH SOIL SAMPLING LOCATIONS] This diagram depicts the snail-shaped Westport Office Park area, and identifies soil sa...
