SITE INFORMATION AND CORRESPONDENCE FILE 2

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Ms. Terry ell July 15, 2003 Page 5 increased MtBE/TBA concentrations in VEW3 may be caused by fluctuations in groundwater elevations and that MtBE associated with earlier releases desorbed from the soil to the groundwater as a result of such fluctuations. The analytical data does not support Palisades' hypothesis. VEW3 has been sampled seven(7) times since installation. See Moise Decl., Ex. 2. Depth to groundwater during these sampling events has varied from 6.82 to 8.71 feet below ground surface("ft bgs"). Id. On February 26, 2001, Bingham McCutchen LLP depth to groundwater in VEW3 was at its highest elevation, 6.82 ft bgs. Id. binghom.com During this sampling event, MtBE was not detected at or above laboratory reporting limits, using EPA Method 8260. Id. If, as Palisades claims, desorption of MtBE already in soil from previous releases caused subsequent detections of MtBE in groundwater, MtBE should have been detected during this sampling event(which it was not),thereby negating Palisades' claim that increased MtBE concentrations in VEW3 were caused by desorption of MtBE from previous releases. Second, Palisades suggests that if its UST system had leaked, concentrations of BTEX should also be relatively higher. Palisades' reasoning completely ignores the potential for oxygenate vapor releases from UST systems. As the SWRCB acknowledged in sponsoring AB 2481, UST system vapor leaks are of potential concern and can be a significant source of potential groundwater contamination.$ Contrary to Palisades' position, the MtBE and TBA 8 AB 2481 addressed vapor leaks from UST systems through a host of statutory changes. See Cal. Health& Safety Code §§ 25290.1(a), (c)(1), (c)(2) (stating that primary and secondary containment must be product tight so that it is"impervious to liquid and vapor of the substance that is contained, . . . so as to prevent the seepage of the substance from the containment");Id. § 25290.1(d) (stating that the UST system"must be designed and constructed with a continuous monitoring system capable of detecting the entry of the liquid- or vapor-phase of the hazardous substance stored in the primary containment into fhe secondary containment and capable of detecting water intrusion into the secondary containment");Id§ 25290.10) (stating that the USTs must be tested after installation(but before being put into service) using one of the following: enhanced leak detection("ELD"), an inert gas pressure test certified by a third-party and approved by the SWRCB, or a test method deemed equivalent to ELD or an inert gas pressure test by the SWRCB);Id. §§ 25292.5(d), 25292.4(d) (stating that if the ELD testing results show that the UST system is leaking liquid or vapor, the owner or operator must correct the (Footnote Continued on Next Page.)