2012-03-12_REPORT - C1982056 (2)

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Discharge Application, which was subsequently approved ( Outfall 001A under CO- G072272). CDPHE requested preliminary analyses of this water for alkalinity, COD, pH and TDS. A sample was collected and analyzed for these parameters. A discharge channel was constructed in late July 2006, and weekly monitoring of discharge from outfall 001A began in August 2006. Note that water was pumped from the sedimentation pond through 001A on an as needed/ sporadic basis. Pump flows were estimated. CDPHE Discharge Monitoring Reports are copied to DRMS. Outfall 001 A was recorded as flowing in March 2011 for approximately five consecutive days. There was no further flow in 2011. No exceedances were noted. TC subsequently applied for a CDPS permit to make 6MN a permanent Outfall. A permit (COG- 850051) was subsequently approved in January 2010 by CDPHE, effective February 1, 2010, expiring June 30, 2013. Temporary Discharge Permit COG - 073311 A temporary CDPHE construction permit was applied for in March 2010, to allow a one foot diameter HDPE pipe line to cross under Fish Creek. This was a mine dewatering pipeline running from the 18 Left Fan pad area, and connecting with an existing pipeline which is used to dewater the old Western Mining District (also see TR09 -70). Mine water from these areas is pumped through the piping to the Area # 1 Pit. Elevated values of total suspended solids were reported to CDPHE for months April through July 2011. These values were attributable to natural high flow erosion impacts along Fish Creek, and not from the pipeline construction back in April. Historical data on Fish Creek immediately upstream of the crossing indicated that elevated TSS values during high flows on this creek are typical. For example, a sample collected upstream of the pipeline crossing yielded a TSS of 259 the last week of May versus the permit limit of 45 mg /L. The permit parameter limit constraints are simply not practical /realistic for that type of project. This permit was terminated by CDPHE as of November 1, 2010. CDPHE Discharge Permit COG - 850054 The 18 Left Vent Fan Pad area drains into two sedimentation ponds which could discharge into a small unnamed tributary leading to Fish Creek. In February 2011, TC submitted an application to CDPHE to make this a permanent CDPS site (also see TR09 -70). A permit (COG- 850054) was subsequently approved by CDPHE, effective April 15, 2010, expiring June 30, 2013. DRMS is copied on CDPHE DMRs for this site. There was approximately six consecutive days of discharge from this site in 2011. 3.7 Mine Water Discharge Sites Four mine water discharge sites associated with the TC operations are monitored. Site 109 requires quarterly monitoring for flows, field parameters, and water quality samples (when flowing), and site 115 is monitored as a CDPS discharge point in accordance with the requirements set forth under CDPS Permit No. CO- 0042161. 14