SITE INFORMATION AND CORRESPONDENCE_2001-2018

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Mr. Jeff Goold • - 2 - • 14 February 2008 Shell Stockton Terminal G project, would be leaving soon for maternity leave, and that Mr. Goold would temporarily assume her responsibilities in her absence. Discussions in the 29 November 2007 teleconference primarily addressed Shell's concerns about discharge of the treated DPE effluent and the effluent limit for TBA. Mr. Gaarder said the easiest discharge option is using Shell's existing City of Stockton (City) sewer discharge permit, but Shell has had problems in the past meeting the City's five microgram per liter (pg/L) TBA effluent limit and the lower explosive level (LEL) threshold. Shell stated that the LEL exceedences were caused by excess methane levels backing up from the City's sewer system, and Shell can control that problem. Shell said the bigger problem is meeting the City's TBA effluent limit, and they wish to avoid a City notice of violation (NOV), even one that carries no monetary penalty. Shell requested more time to appeal to the City to raise the discharge limit to 12 parts per billion (ppb) and allow an occasional violation, which they had been able to arrange with one other municipality. Regional Water Board staff agreed with this strategy and scheduled a 14 December follow-up teleconference. During the 14 December teleconference, Shell stated that they had decided to discharge wastewater generated during the DPE pilot test to a holding tank and transport it to Shell's refinery in Martinez, as is currently done with groundwater generated from the groundwater pump and treat system. Shell also addressed Comment No. 3 listed above by consenting to conduct DPE testing in all three SAs. In response to the other comments listed above Shell 1) stated that they did not have enough information to provide costs for the excavation and SVE/AS options, 2) stated that site-wide groundwater cleanup cannot be completed due to current site use but would be re-evaluated if site use changes in the future, and 3) acknowledged that not much is known about the pump except that is permanently lodged at the bottom of MW-10. To conduct the DPE pilot test, Shell proposes to install three 4-inch diameter DPE extraction wells in the MW-1, MW-10, and MW-13 SAs and two 2-inch diameter observation wells in the MW-1 and MW-10 SAs using hollow-stem augers. Shell proposes to first dewater the saturated soils by running the extraction wells for one week prior to the start of the DPE test. DPE testing will be conducted sequentially in each SA by incrementally increasing the vacuum to the maximum airflow rate and then conducting a 24-hour DPE operation to determine if the rate can be sustained. Extended testing may be conducted in a select SA following the initial one-day test. Groundwater extraction will be performed using a trailer-mounted liquid-ring pump and thermal/catalytic oxidizer (trailer) to treat extracted vapors to San Joaquin Valley Air Pollution Control District requirements. The extraction system is equipped with a knock-out tank to remove entrained groundwater from the vapor stream. Groundwater drawdown and induced vacuum will be monitored in the newly installed 2-inch diameter observation wells, and in other proximal wells during the DPE pilot test. An organic vapor analyzer (OVA) will be used to field measure hydrocarbon vapors in the extracted vapor stream, and vapor samples will periodically be collected in one-liter tedlar bags for laboratory analysis. Laboratory analysis will