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a release/termination would need to be proposed by the permittee, Idarado, and eventually <br /> accepted by DRMS. Although numeric standards have not necessarily been required in the <br /> past, a quantifiable goal to demonstrate an appropriate level of remediation/reclamation that is <br /> protective is the basis for acceptance. Based on this, it appears that DRMS would be <br /> amenable to a reclamation proposal from Idarado which affords human health protectiveness <br /> and safety given a particular post-reclamation use such as summarized above. <br /> Additionally, we contacted the Colorado Department of Public Health and Environment <br /> (CDPHE). In considering the historical approaches to remediation for Voluntary Cleanup <br /> within the Brownfields regulatory framework of the CDPHE, there does not appear to be a <br /> specific standard set here either; but again, there is a reliance on the applicant to demonstrate <br /> the planned remediation is protective for the intended end use. <br /> Proposed Cleanup Criteria <br /> Given the above-stated guidance, the permittee has the opportunity to select an applicable <br /> cleanup standard. Therefore, we compared the limited site-characterization data to two <br /> established standards. The contaminants of concern (COCs) are primarily arsenic, lead, and <br /> zinc based on our experience at similar sites. <br /> We considered threshold values from various agencies for heavy metal contamination in soils. <br /> We first completed a comparison of the analytical results with the 2011 Colorado Soil <br /> Evaluation Values (CSEV) for On-site Worker Exposure to metals in soils. The Paris Mill <br /> used these criteria for the determination of soil contaminated with mill tailings that would <br /> need to be removed as part of the Voluntary Cleanup in Park County, Colorado in 2011 (Final <br /> Voluntary Cleanup Application, Paris Mill Site Tailings Reclamation, Park County, <br /> Colorado; September,2009; RMC Consultants, Inc.). <br /> Another source of evaluation to establish an acceptable standard was to consider the <br /> document Risk Management Criteria (RMC)for Metals at BLM Mining Sites, Technical Note <br /> 390 rev. October 2004 (Attachment A, table only) with the primary objective of this report <br /> being to establish risk management criteria (RMC) for human health and wildlife. Risk <br /> management criteria provide numerical action levels for metals in environmental media (soils <br /> and/or sediments). RMC values are designed (1) to assist land managers in making natural <br /> resource decisions, and (2)to support ecosystem management. <br /> While this clearly isn't directly linked to the Pandora Mill as it is not on BLM land, the BLM <br /> document does evaluate exposure pathways for COCs (heavy metals) associated with mining <br /> contaminants. BLM's "camper" visitor receptor would best fit the occasional visitor at the <br /> Pandora Mill but would provide a very conservative estimate as the length of exposure to a <br /> potential pathway for a BLM camper would be significantly longer than for the occasional <br /> visit to the Pandora Mill for a tour. The worker scenario pathway would best associate with <br /> the tour guide but more appropriately to a worker doing repair or maintenance on the facility. <br /> RMC values for the contaminants of concern for the camper (exposed to "sediments") are <br /> summarized in Attachment A. <br /> 3 <br />