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<br />August 31, 2010 <br />Mr. Ben Frei <br />Certificate of Designation Application for Frei-Henderson Inert Landfill <br />Completeness Review Determination: Complete <br />Page 5 <br />requirements. Additional detail is particularly required along the southern property boundary <br />were the drawings seem to indicate that inert material filling will create depressions on the <br />adjacent properties where stormwater will be trapped, and will pond. <br />14. Section 5.1.1- Inert Materials: The DOP does not adequately address waste screening <br />procedures. Section 5. 1.1 states that "only uncontaminated materials are acceptable. " <br />However, the DOP does not define "uncontaminated," nor does it describe how the operator <br />will confirm that materials are uncontaminated. Detailed waste screening procedures must be <br />developed and incorporated into the DOP. The waste screening procedures must address each <br />inert material that is listed in Section 5.1.1. <br />Since much of the inert material proposed for landfilling will be placed below the pre-mining <br />groundwater levels proper characterization and screening of soil and other inert material is very <br />important. The screening procedures should describe procedures that will be used for small <br />quantities received from the general public as well as large volumes generated from a particular <br />site. <br />Because certain inorganic compounds, such as those found in Appendices IA and 113 of the <br />Solid Waste Regulations, can be naturally occurring in some geologic environments in <br />Colorado at fairly high concentrations, it may be necessary to evaluate and test, as appropriate, <br />potential fill material before it is delivered to the site. Such screening is especially important <br />for large-volume projects and/or for projects where contamination is suspected based on prior <br />land-use activities or other site-specific knowledge. The waste screening procedures must <br />describe how test results will be evaluated to determine whether inert material is suitable for <br />acceptance. The Division's 1997 Soil Remediation Objectives Policy Document <br />h( ttp.ww.cdphe.state.co.us/hm/ soilplcydraft.pdf) and corresponding Colorado Soil <br />Evaluation Values ("CSEV") Table 1 (December 2007) provide useful guidance. Section 6.5.4 <br />of the draft policy document provides recommendations for test procedures to estimate the <br />concentration of inorganic constituents that are likely to leach from soil to groundwater. Using <br />fate and transport modeling the Division established Leachate Reference Concentration values <br />for a number of inorganic constituents. Leachate Reference Concentration values are presented <br />in CSEV Table 1. If leach test results are equal to or below the Leachate Reference <br />Concentration values, it is assumed, based on fate and transport modeling, that the soil will <br />pose little to no threat to local groundwater quality. Conversely, if the leach test results exceed <br />the Leachate Reference Concentration, it is assumed that the soil will leach hazardous <br />substances to groundwater and potentially degrade the groundwater quality in excess of the <br />allowable standards. <br />Soil testing procedures similar to those described in Section 6.5.4 shall be incorporated, as <br />appropriate, into the DOP as a means of screening for potentially contaminated soil. Each <br />potential source of fill material shall be evaluated based on considerations such as: site <br />location, prior and current land use, quantity, odors, color, staining, etc., to determine necessary <br />testing parameters and frequency of testing to adequately characterize the potential fill material.