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Honoring all shallow analytical results within the impacted area the average concentration 80% <br /> confidence intervals are: <br /> Total Lead: 64.45 <_ it <_ 114.67 ppm <br /> Soluble Lead: 3.91 <_ it 5 10.19 ppm <br /> Excluding the three samples analyzed by Argon in the area of impact the equivalent confidence <br /> intervals are: <br /> Total Lead: 45.24 <_ µ <_ 78.76 ppm <br /> Soluble Lead: 1.71 <_ µ <_ 5.79 ppm <br /> In either event the total lead concentrations within the impacted area do not exceed the Cal EPA <br /> Modified PRG of 130 ppm. Accordingly, no significant risk to human health or the environment <br /> is posed by the impacted soil. <br /> 8_0 Remedial Options <br /> In the development of recommendations for remedial action, four options were considered: no <br /> action, paving, insitu treatment of soil, and soil excavation. Approximate costs for each option <br /> are detailed in Attachment C. <br /> 8.1 No Action <br /> There would be no further work with this option. Insofar as the lead concentrations at the site <br /> do not exceed the PRG level, no significant health threat would be expected to result from this <br /> option. The lack of elevated lead concentrations in samples collected below 1.5 feet and the low <br /> solubility of the lead in water indicates that the lead is immobile and does not pose a threat to <br /> groundwater quality by leaching. The estimated cost of this option is $ 0. <br /> 8.2 Paving <br /> This option would involve paving the area from the northeastern portion of the property east of <br /> the line established by samples SS-2 and SS-3 southward along the eastern edge of the existing <br /> building to the vicinity of soil sample CC, or approximately 2,300 fe. <br /> Implementation of this option would provide additional protection against human exposure to the <br /> lead by eliminating the possibility of dust inhalation or direct contact. The option would provide <br /> additional protection against leaching of the lead by isolating the contaminated soil from rainfall <br /> infiltration. The estimated cost of this option is approximately $ 9,100. More details on the <br /> expected costs associated with this option are presented in Attachment C. <br /> roys\rep-U\--nwy 8 <br />