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Pitch Reclamation Project Colorado Mined Land Reclamation Board — 2016 Annual Reclamation Report 4.5.2 Rock Dump Water Levels Historically, the water levels in rock dump piezometers show little fluctuation in the winter months with a temporary rise in response to the spring snow melt. They usually return to normal levels in mid to late summer. The piezometer readings in 2016 were indicative of a moderate snow pack when compared with the 2012 and 2013 readings, but below the snow pack and total annual precipitation in 2014 and 2015. During the monitoring period of November 2015 through October 2016, the onsite precipitation gage recorded 20 inches of precipitation, compared with 23 and 31 inches during the 2015 and 2014 periods, respectively. 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 4. The replacement piezometer IC10300R is located approximately 30 ft to the west of the former location of IC10300. Piezometer IC10370R is located approximately 67 ft to the west of the former location of IC10370. More details on the replacement piezometers were provided in a detailed report to DRMS in October 2011. The rock dumps were inspected monthly in 2016, except when winter conditions prohibited access, in accordance with the recommended monitoring program. The inspections and monitoring conducted in 2016 indicate stable conditions for the Indian and Tie Camp rock dumps.A more detailed discussion of the rock dumps is provided in the 2016 Annual Geotechnical Report, which was filed with DRMS in January 2017. 4.6 Colorado Discharge Permit System Monitoring As outlined in TR-4 to the reclamation permit, HMC has monitored water quality since 1994 to verify the intended effectiveness of installation of the Pinnacle Adit plug. Water quality monitoring was conducted in 2016 including sampling points located at the North Pit Lake discharge(Sample Point NPL), the Tie Camp drainage(Sample Points TCDRN and TCC),the CDPS permit compliance point(SW-33), as well as spring and seep surveys performed in the spring and fall (Figure 4). Monthly discharge-monitoring reports (DMRs), pursuant to CDPS permit No. CO-0022756,were submitted to the Colorado Department of Public Health and Environment (CDPHE) Water Quality Control Division (WQCD) throughout 2016. 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 2016, all analytical results were below the CDPS permit's 30-day average or daily maximum limitations, and WET tests passed consistent with historic results. The 2016 DMRs are on file with the WQCD. Water quality monitoring will continue in 2017. 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. HMC provided comments to the WQCD on March 17, 2014. The CDPS permit was administratively extended on September 1, 2015.A final CDPS permit was not issued by the WQCD in 2016. 4.7 Establishing the Lowest Practical Level for Uranium The 2012 triennial review for the Gunnison Basin resulted in changes to Regulation#35 (classification and numeric standards for Gunnison and Lower Dolores River basins), including addition of a Type B seasonal Temporary Modification for acute (daily maximum) and chronic (30-day average) uranium standards to Segment 20 (Indian Creek) effective in 2013. The Temporary Modification for uranium was 1,515 pg/L (acute)and 1,349 pg/L(chronic)for June through July, and 1,144 pg/L(acute)and 1,080 pg/L(chronic)for August through May. The WQCD indicated that the Temporary Modification was needed to better reflect the ambient conditions on Indian Creek and provide HMC sufficient time to establish the LPL of uranium 27