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mine site are summarized in Tables 2 through 4, (5CCR 1002-31). The Basic Standards and
<br /> Methodologies for Surface water are presented with the exception of providing a standard for
<br /> total residual chlorine, sulfide and asbestos.
<br /> Since five (5) quarterly samples have been obtained from the Upper Deadwood Gulch sampling
<br /> (DG-1) station and two from the designated La Plata Wetlands sampling site (LP-1), future 1
<br /> sampling/testing at these site will be performed on a biannual basis (twice a year).
<br /> In general, surface water quality characteristics can be considered excellent. Dissolved metals,
<br /> totals and total recoverable solids and nutrients, are low. The pH is consistently recorded at 7.3
<br /> and less than 8. The existing water quality meets physical, biological, inorganic and metal
<br /> standards for the period of record. In addition, the Division stated the OPERATOR after"five
<br /> sampling events, water quality analytes have repeatedly registered undetectable concentrations
<br /> in the analysis will be deleted from future surface water sampling events: aluminum, ammonia,
<br /> antimony, beryllium, boron, cadmium, cobalt, cyanide, lead, iron, manganese, mercury,
<br /> molybdenum, nickel, selenium, silver, thallium, uranium, vanadium. Thus, these analytes have
<br /> been removed from further sampling/analytical events.
<br /> 7.3.2 Groundwater Quality
<br /> Groundwater samples have been taken from the Idaho seep and four wells (one alluvial and the
<br /> others are proximal to the mine portals. The Idaho seep (Table 9), the May Day No. 1 Portal
<br /> Area Table 10; the May Day No. 2 Portal Area(Table 11); La Plata River Alluvium (Table 12),
<br /> and the Idaho Well (Table 13).
<br /> Ground water samples were taken in accordance with the Standard Operating Procedures for the
<br /> following:
<br /> • Purging and Sampling Monitoring Wells;
<br /> • Groundwater Sampling;
<br /> • Monitoring Well Installation;
<br /> • Well development; and
<br /> • Pumping Tests
<br /> Site groundwater quality can also be considered excellent. Total metals are low and nutrients are
<br /> non-existent. The pH is consistently recorded at 7.3 or above and less than 8. Colorado
<br /> Department of Public Health and the Environment (CDPHE)pH discharge limits range between
<br /> 6.5 and 9. Groundwater quality conforms to Colorado Groundwater water quality standards
<br /> (Table 3)2. Water quality testing was not required for the following parameters: coliforms,
<br /> asbestos, chlorophenol, color corrosivity, foaming agents, odor,phenol, gross alpha particle
<br /> activity and beta/photon emitters. (Dustin Czapla, Environmental Protection Special
<br /> Correspondence May 29, 2012). In addition, The OPERATOR analyte list would be reduced if
<br /> "after five sampling events, analytes that repeatedly register undetectable concentrations in the
<br /> analysis may be eliminated subject to DRMS approval. (Czapla, Dustin, May 29, 2012) Based on
<br /> 2 CDPHE WQCC(5CCR 100241,the Basic Standards for Groundwater-Tables 2-4
<br /> May Day Idaho Mine Complex
<br /> M-1981-185
<br /> January 19, 2017
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