2015-04-17_REPORT - M1977004 (2)

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Pitch Reclamation Project Colorado Mined Land Reclamation Board — 2014 Annual Reclamation Report In 2011, piezometers IC10300 and IC10370 were replaced after several years of issues associated with corrosion and silt buildup in the well casing making it difficult to get an accurate reading of the phreatic surface in the Indian rock dump. They were replaced with two new piezometers at approximately the same locations as shown on Figure 3. The replacement piezometer IC1030OR is located approximately 30 feet to the west of the former location of IC10300. Piezometer IC1037OR is located approximately 67 feet to the west of the former location of IC10370. More details on the replacement piezometers were provided in a detailed report to the Division in October 2011. In general, the peak water levels in the rock dump piezometers reflected the heavier than typical snow pack of 2014, and the December water levels did not fall back to seasonal lows due to heavier than typical late summer rains. The 2014 water level measurements showed a maximum differential following snow melt above the 2013 and much higher than 2012 measurements, but below that of the previous five years due to differences in snow pack and summer precipitation. Following the dry conditions of 2001 through 2003, the seasonal variations had increased in recent years as heavier snow packs had occurred, with 2012 being a relatively dry year. The replacement piezometers in the Indian rock dump have alleviated siltation issues in monitoring the phreatic surface in the rock dump. We will continue to monitor and evaluate the cause and effect of any seasonal spikes in the piezometric water levels, observe any changes in surface features of the rock dumps and repair as needed. There continues to be no indication of concern related to slope or foundation instability or elevated phreatic surfaces in either the Indian or Tie Camp rock dumps. I A more detailed discussion of the waste rock dumps was presented in the 2014 Annual Geotechnical Report filed with the Division in January 2015. 4.6 Water Quality Monitoring & Colorado Discharge Permit System As outlined in TR4 to the Reclamation permit, Homestake has monitored water quality since 1994 to ' verify the intended effectiveness of installation of the Pinnacle Adit plug. Water quality monitoring was conducted in 2014 including sampling points located at the North Pit Lake discharge (Sample Point NPL), the Tie Camp drainage (Sample Points TCCDRN and TCC), the site discharge POC (Sample Point SW- 33), as well as spring and seep surveys performed in the spring and fall. Monthly discharge- monitoring reports (DMRs), pursuant to Colorado Discharge Permit System (CDPS) number CO- 0022756, were submitted to the Water Quality Control Division (WQCD) of the Colorado Department of Public Health and Environment (CDPHE) for 2014. Monitoring for the CDPS was conducted at the designated POC SW -33, shown on Figure 3. Analytical tests conducted for the DMRs at SW -33 consist of flow; dissolved radium 226; total radium 226/228; total uranium; pH; total suspended solids (TSS); total dissolved solids; oil and grease (visual only); potentially dissolved zinc; and whole effluent toxicity (WET). During 2014, all analytical results were below the CDPS permit's 30 -day average or daily maximum limitations and WET testing results were within permit limits. The 2014 DMRs are on file with the WQCD. Water quality monitoring will continue in 2015. At the request of the WQCD, an early permit renewal application was submitted on December 2, 2013. In January 2014, the WQCD published a draft renewal permit for public ' review and comment. Homestake provided comments to the WQCD on March 17, 2014. A final renewed CDPS permit was not issued by the WQCD in 2014. In 2013, the Water Quality Control Commission issued a Seasonal Type B Temporary Modification on Segment 20 (Indian Creek). The modification was intended to provide sufficient time to determine the "lowest practical level" (LPL) of uranium discharged to Indian Creek at the discharge permit point of ' compliance (SW -33). In 2014, Homestake implemented a plan to assess both natural and human - induced sources of uranium to support an evaluation of mitigation options that are practical and technically and economically feasible. Work performed during the past two years has established a fundamental I Pitch 2014 Reclamation Report 16Apnl2015_Cw.Docx 1 27