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<br /> Figure 2. CC&V compliance groundwater monitoring locations
<br /> 3. Previously Established Numeric Protection Limits
<br /> As further described below, DRMS has issued NPLs for the CC&V mine site four times over the last
<br /> eleven years. In issuing these NPLs, we understand that DRMS personnel complied with the Division's
<br /> regulatory mandate to use its best professional judgement in analyzing the submitted data to determine
<br /> NPLs that deviated from the criteria in Tables 1 through 4 of Colorado Regulation 41, The Basic
<br /> Standards for groundwater. In using their best professional judgement, DRMS personnel appropriately
<br /> determined that the groundwater quality of the sites reviewed was not impacted by sources of
<br /> groundwater contamination since January 31, 1994, and subsequently that the observed groundwater
<br /> quality is representative of water quality prior to January 31, 1994.
<br /> DRMS issued NPLs to CC&V via correspondence on the following dates: October 7, 1996, November 20,
<br /> 1998, May 18, 2006, and August 7, 2012. NPLs received on October 7, 1996, DRMS issued NPLs
<br /> pertaining to all groundwater monitoring locations at the CC&V mine site and set numerical protection
<br /> limits for the following analytes: aluminum, arsenic, cadmium, copper, fluoride, iron, lead, manganese,
<br /> mercury, nickel, nitrite, nitrate, nitrate & nitrite, selenium, zinc, cyanide (WAD), and pH. On November 20,
<br /> 1998, DRMS issued NPLs pertinent to monitor wells CRMW-3B-63, GVMW-8A-250, and WCMW 6-234
<br /> and contained NPL values for manganese, cyanide (WAD), pH and sulfate. On May 18, 2006, DRMS
<br /> issued NPLs for Vindicator Valley compliance well VIN 2B, which included NPL information for
<br /> manganese, cyanide (WAD), pH and sulfate. On August 7, 2012, DRMS issued updated NPL information
<br /> for WCMW-6 and new NPL information for WCMW 3-134, which included NPL values for manganese,
<br /> zinc, cyanide (WAD), pH, and sulfate. NPL documentation received from DRMS for the CC&V mine site
<br /> for the above referenced dates are included within Attachment A.
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