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Chevron Mountain View Town Homes -2- On 13 and 14 February 1996, EMCON completed the installation of ground water monitoring wells MW-1, MW-2 and MW-3 and took samples on 16 February 1996. These wells were sampled again in March, May and September 1997. No BTEX, TPH as gasoline or PAHs were detected in any of the ground water samples taken. In addition, TPH as diesel was detected in the ground water sample and duplicate sample collected from MW-1 during the March 1997 sampling event as 130 ppb but was not detected during the May or September 1997 sampling event. The consistent absence of any BTEX, TPHg and PAHs in ground water samples collected over four sampling events suggests that any of these compounds potentially present in the impacted soils have reached equilibrium in the soil/water system present in the impacted area. Rationale for No Further Action The compilation of the data supports the following: 1) The weathered nature of the petroleum hydrocarbons in the subsurface indicates natural attenuation is occurring; 2) Petroleum hydrocarbons in the subsurface are not adversely affecting the local or regional ground water quality; 3) Shallow soil was excavated during and immediately following the removal of the WMR pipe lines. The extent of remaining soil contamination has been well-defined, and because of the physical properties of weathered petroleum hydrocarbons in soil, it appears unlikely that residual hydrocarbons at the site could be a source of dissolved hydrocarbons to ground water. The results of the ground water monitoring conducted by EMCON show there is not a ground water plume and that natural attenuation is likely occurring in the ground water and/or at the soil ground water interface. It is my best professional judgement that if further cleanup were required at the Mountain View Town Homes Site, the benefit to the people of the State would not outweigh the burden placed the Chevron Pipe Line Company. GAI:gai/lsb