SITE INFORMATION AND CORRESPONDENCE

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f R & L Diesel page 2 2417 West Lane June 12, 2008 Stockton, CA completed about five feet west of the fill pipe for the former UST. The EHD was informed the ,I total depth of that boring was 48 feet and there was odor to the soil at 19 and.29 feet. The third boring was a slant boring, located northwest of the s cond boring and about 11 feet from the fill pipe for the former UST. The third boring was abo t 32 feet in length and estimated to have reached a total depth of 29 feet below ground surfs (bgs). The fourth boring was also a slant boring, located southwest of the second boring and about 11 feet from the fill pipe for the former UST. The fourth boring was about 24 feet ir length and estimated to have reached 19 feet in depth bgs. There was odor to the soil sample from this boring. E The information in the Report is not consistent. It states in the narrative that the Geoprobe was "used to secure the samples, five with the drill vertiail, one with the drill angled at 24° from the vertical, and one 18° from the vertical". The EHD interprets these statements to mean that there were at least two slant borings performed which is consistent with the EHD field notes. There is a drawing in the Report labeled "Plan View" that indicates 61 and B2 were vertical and B3 was angled. This is not consistent with the Report narrative statement that there was a 24° slant boring and an 180 slant boring. The drawing i dicates three sample locations on B1, two sample locations on B2, and three samples locations on B3. EHD has determined that the first r sample location for B3 was actually the sample collected from an angle boring in February 2007 as noted on Table 1 in the Report. The drawing shows that both samples from B3 were collected beneath the former UST. The only way to obtain samples from different depths that are directly beneath a closed in place UST as shown on the drawing is from two different angle borings. If only three samples were collected from 131 and one sample was collected from each slant boring, the other samples must have been collected from another vertical boring as observed in the EHD field notes. The Report states that "Bore hole locations are shown on Figure 4 from the Work Plan". The bore hole locati ns were changed from the original work plan proposal figure as well as the number of borings due to site conditions as discussed above so a new figure should have been provided. There is no chain of custody for the samples submitt d to the laboratory for analysis and there is no laboratory Quality Control data for gasoline 3nalysis using the LUFT/GCMS method. Please submit copies of the chain of custody and the Quality Control data to the EHD by June 26, 2008. The laboratory reports indicate that sampl s 131-14, B1-24 and B1-44 were taken at 9:30, 10:00 and 10:15 respectively, that samples B -19 and 132-29 were taken at 11:30 and 12:00 samples P, and that les B3-21 and 133-29 were taken at 15:00 and 14:15 respectively. EHD does not understand how a sample could have been collected from B3 at 29 feet bsg prior to collection of the sample from B3 at 21 feet bsg. The EHD suspects that B1 was the first vertical boring north of the former US , ,that .B2 was the second vertical boring west of the former UST, that sample 63-29 was collected from the slant boring to the northwest of the former UST and that sample 133-21 was collet ed from the slant boring to the southwest of the former UST. The Report states that the work was completed under oversight by Margaret Lagorio from the EHD. The EHD inspects the work and notes information and observations but does not accept responsibility for oversight of the work. The appropriately registered or certified professional, in this case Tom Ballard, is responsible for oversight of the work performed. The oversight provided by the EHD is to evaluate site information provided by the PG or PE Civil and direct action as determined necessary.