2016-03-24_REPORT - M1977424 - Laserfiche WebLink

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Logan Wash Mine Annual Report Permit No. M-1977-424 Historical and 2015 analytical results for mine water(LW-001),retort water(LW-Retort), and Well LWCW-lA are shown in Tables 5, 6, and 7,respectively. The analytical results for samples collected during the reporting period do not indicate a significant improvement of retort water quality compared to past sampling events. Four additional locations were added to the sampling schedule in 2015.Two of the locations are considered to be potential source waters of mine water discharge, "Big Seep"and"Research Mine Tributary". "Big Seep"emanates from the rock wall above the Daylight Portal and was sampled in May and October of 2015. "Research Mine Tributary"flows through the drainage above the Research Mine at the head of Logan Wash and was sampled in May of 2015; no flow was present in October of 2015. In addition, samples were collected in May and October of 2015 from Well LW-22A, an alluvial well located in Logan Wash approximately 2.25 miles down Logan Wash from the mine. Samples of the retort water flowing through the Lower Manhole (LW-LM)were also collected in May and October of 2015. Locations sampled during the spring 2015 semi-annual sampling event are shown in Figure 5.Analytical data from all of these samples is shown in Table 8. 3.4 Research Mine Manometer Monitoring The manometer installed in the Research Mine Vault is monitored and recorded on a monthly basis and on a more frequent basis in the spring months of April and May, or until the peak level begins to subside. If manometer measurements were to indicate a very high(> 36 inches)reading for more than a week's time,the water in the mine can be released and sampled. The manometer level was 0 inches throughout the reporting period. 3.5 Evaporation Pond Leak Detection System Monitoring of the Evaporation Pond Leak Detection Vault is conducted by continuous measurement of water pressure(depth)in the vault sump using an installed pressure transducer. On-site monitoring is conducted monthly as access conditions allow. Figure 6 shows the pressure transducer water depth results for the period October,2011 to February,2016. During the reporting period,the pressure transducer log indicated that the Leak Detection Vault slowly received water beginning in late March,2015 and reached the automated pumping depth of approximately 1.1 feet in mid-May. The slow flooding sequence repeated itself pumping again in mid-July. After this, intermittent pumping occurred in August,when late in the month battery failure apparently occurred. Water level in the vault attained approximately a 4.75 foot depth, before batteries were replaced in mid-September and again with a new solar controller on September 21.Another flooding cycle occurred in late October and the pump was replaced on November 10,which appeared to have fixed the intermittent pumping problem. Based on observations of suspended buckets under the three collection pipes, it appeared water had entered the vault through the east drainage pipe. Periodic inspections of the liner did not reveal any new open holes, cuts or cracks near the water line. 3.6 Precipitation Precipitation was monitored on the Lower Bench and at the Evaporation Pond through the use of Novalynx Corporation Model 260-2101 SK-P rain gauge instruments. The Lower Bench gauge is typically operational from April through December, depending on access to the bench.The Western Water & Land, Inc. 7