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custody are included in Appendix A. <br /> 4.2 Domestic Well <br /> No TPH or BTE&X were detected in the domestic well . Halogenated <br /> solvents were detected in the first sample from the domestic well <br /> (April 8) at levels ranging from 1. 4 ppb (methylene chloride) to <br /> 230 ppb (1, 1-dichloroethylene) . Eleven HVOC compounds were <br /> detected in the confirmatory sample collected on May 4 , 1993 . The <br /> HVOC levels ranged from 0 . 16 ppb (tetrachloroethene) to 81 ppb <br /> (1, 1-dichloroethene) . The laboratory results are summarized in <br /> Tables 1 and 2 . The laboratory report and chain of custody are <br /> included in Appendix B. <br /> I <br /> 5.0 CONCLUSIONS AND RECOMMENDATIONS <br /> 5.1 Monitoring Well <br /> Benzene concentrations have increased in MW-2 from 1 . 0 ppb in <br /> January of this year to the current 8 . 5 ppb. In the initial <br /> sampling, TPH were reported at 83 ppb, although this concentration <br /> was determined to be the result of the presence of the halogenated <br /> solvents (see "Monitoring Well Installation Report" by GeoAudit <br /> dated January 28, 1993) . No TPH were reported in the most recent <br /> sampling of MW-2 . <br /> E In general, the HVOC concentrations have decreased since the <br /> January sampling. The source of the HVOC's is still unknown, but <br /> probably did not originate on the subject property. GeoAudit <br /> recommends that MW-2 be re-sampled by mid-July of this year. <br /> 5.2 Domestic Well <br /> Most of the HVOC' s detected in the domestic well exceed Maximum <br /> Contaminant Levels (MCL's) or Action Levels (AL' s) for drinking <br /> water in California. It is our understanding that arrangements have <br /> been made by Marlowe Properties to provide bottled water to all <br /> tenants supplied by the domestic well. <br /> GeoAudit recommends the installation of a filter system on the <br /> existing domestic well or the installation of a new drinking water <br /> well to supply the property. <br /> t 5.3 Soil contamination <br />■ Some residual soil contamination still remains in the area of the <br /> former UST. With groundwater levels rising, this soil contamination <br /> could represent a possible source of continuing contamination of <br /> the groundwater. Therefore, the remaining soil contamination in the <br /> area of the former UST should be assessed and a remediation plan <br /> implemented. <br /> 3 <br />