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L7ydF+ C n W� The previously mentioned trigger cleanup level of 0.3 ug/L is the initial level established for the preliminary stage of the site evaluation. At the present time, there are no specific action 1 i levels or other criteria for determining the allowable hydrocar- bon concentrations which may remain in place in the soils. The cleanup levels are determined on a case by case scenario based on 47 specific site characteristics. As a general guideline, the. San ' Joaquin Local Health District recommends 100 mg/kg of TPH as a r cleanup level, as well as the other associated chemical concen- trations listed on Table 1. These levels supersede the initial trigger leve]• and can be assumed to be the designated cleanup levels. 4.2 water Samples Three shallow groundwater wells, Mw-1, MW-2 and MW-3, were in- stalled at the site; located as shown on Figure 3 and water - samples were collected using a clear teflon bailer. The specifics of the groundwater sampling effort are described in detail in the Field Sampling Report contained in Appendix A. ._. The analytical results of the groundwater samples are summarized in Table 3. These results reveal significant concentrations of BTX&E compounds and TPH in the water sample collected from monitoring well MW-2. BTX&E compounds were detected only in low concentrations in monitoring well MW-3. No organic compounds analyzed for were detected n the water sample from MW-1. No ,._ floating product was observed in any of the monitoring wells. For dissolved product, such as was detected in wells MW-2 and NW-3, the Department of health Services (DHS) has established action levels for drinking water. These levels are: o Benzene 0.7 ug/L o Xylene 620 ug/L o Toluene 140 ug/L o Ethylbenzene 680 ug/L A review of Table 3 indicates the chemical concentrations present in monitoring well MW-3 exceed all of these limits while in well ° Mw-3 only the benzene concentration exceeds the action levels ` Even though the DHS action levels for drinking water are exceed- . ed, it is unlikely that the shallow zone can be classified as a "source of drinking water" as specified by the State Water Resources Control Board's Resolution No. 38-63. The Resolution specifies that a water source which does not provide sufficient water to supply a single well capable of producing an average per day (gpd} shall not be sustained yield of 200 gallons considered or suitable for municipal or domestic water supply. Based on WESTON's observations during the prasampling collection purge of the wells (re: Field Sampling Report, Section 3.3, Appendix A) , it is not expected the shallow aquifer can sustain I ' the minimum 200 gpd yield.