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presented in Appendix B. Sonic cement-bond log data from each well was also collected. Welenco's interpretation of the cement-bond logs is included in Appendix C. 4 . 0 EVALUATION OF LOGS Based on the findings of the initial well inspection, the video logging and cement-bond logging, the following is an interpretation of the construction of each of the wells evaluated: 4.1 17950 South Airport Way The domestic well at the above address is constructed with 6-inch inside diameter (I.D.) steel casing. The total depth of the well is 59.0-feet below ground surface (bgs) based on the initial well inspection performed. However, an obstruction was encountered in this well during the video logging at 41-feet bgs. The camera could not be advanced past this depth and no further data could be collected for this well beyond 41-feet bgs. It is noted in Welenco's log that the obstruction may possibly be two pipes of the same length on either side of the casing. Casing seams/joints were noted at 13-feet, 31-feet, and 37-feet bgs. All the casing seams observed appeared to be in good overall condition with no evidence of breakage. The cement bond log for the well showed the presence of cement from the static water level (SWL) of 10-feet to 35-feet bgs. However, according to Welenco, there was less "cement effect" between 18-feet to 24-feet bgs. No slots were observed in the casing to the total depth of the survey o f 41-feet bgs. Water apparently enters the well below this depth. The pump intake was located at 41-feet bgs, which is also the depth of the obstruction encountered by the video log camera. Although it is possible that this well could act as a conduit for the vertical migration of MTBE, depending on the quality of the cement seal, it is ASE's opinion that this well probably is not a significant conduit for the vertical migration of MTBE in the site vicinity. 4.2 17926 South Airport Way The domestic well at the above address is constructed with 4.75-inch I.D. steel casing with an increase to an undetermined diameter at approximately 4-feet bgs. Casing joints/seams were noted approximately every 3-feet. Specific depths where joints/seams were present included approximately 7-feet, 11-feet, 14-feet, 18-feet, 21-feet, 24-feet, 28-feet, 34-feet, 37-feet, 41-feet, 43-feet, 45-feet, and 48-feet bgs. Several of these seams showed corrosion, which could cause leakage. In particular, Franks One Stop Report — February 2001 -2-