SITE INFORMATION AND CORRESPONDENCE

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a Mr. William S. Johnson October 1, 1985 Page Two HYDROGEOLOGY The unconfined groundwater table beneath the Douglas station is contained in a medium to fine grained silty sand zone from a depth of approximately 45 feet to a depth of approximately 65 feet and continues in a sandy clay material to the bottom of the boring. The direction of groundwater flow has steadily been toward the southeast throughout the monitoring period. Table 1 indicates the change in the groundwater elevation from July 1985 until September 27, 1985. In general, the groundwater level has descended more than 5 feet since the installation of MW-1, MW-8, and MW-9 in May 1985. In other words, the ground- water table has descended at a rate of approximately 1.25 feet per month during the dry summer. The product discovered in MW-8 has become suspended in the soil and appears to be localized. Specifically, the lateral extent of the free product does not reach MW-10, MW-12 or MW-14 which are downgradient of MW-8. In addition, MW-11 or MW-13, which are upgradient of MW,8, do not contain any evidence of free pioduct. Samples were taken of each groundwater well on August 27, 1985, by Twining Laboratories, Inc. and analyzed as described in Table 2. Groundwater monitor- ing wells MW-1 and MW-9 did not recharge to an acceptable volume to secure an accurate sample due to their total well depth. The analysis indicates that there is a presence of soluable constituents of petroleum hydrocarbon in MW-10, MW-12, MW-113, and MW-14. CONCLUSIONS The concentration of the soluable constituents of petroleum hydrocarbon found in MW-10 indicate that the leaks discovered at the Phase II Vapor Recovery connections to the storage tanks have not had a significant impact on the groundwater. Furthermore, if the unleaded tank which received the internal epoxy coating had leaked, free product would be present in MW-1 and MW-10 because of their proximity to the storage tanks. The product discovered in MW-8 is localized and is presently suspended in the soils above the groundwater. Extraction of free product is not possible with the current groundwater conditions. However, the unconfined groundwater shall recharge to a higher elevation following the rainy season. It is possible that extraction of free product may be accomplished following the recharge of the groundwater. REMEDIAL ACTIONS - ALTERNATIVE I The groundwater conditions warrant further monitoring on a weekly basis to determine the piezometric level, the direction of flow and the presence of free product. Each groundwater monitoring well shall be sampled and analyzed monthly to determine the concentrations o� soluable constituents of petroleum hydrocarbon.