2011-03-23_REPORT - M1977424 - Laserfiche WebLink

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Logan Wash Mine Annual Report Permit No.: M-1977-424 Monitoring is required at Outfall 001 when mine-water drainage from Logan Wash mine reaches a flume in "Dry Gulch" at the OOSI and BLM property boundary. Prior to 2005, monitoring was required at Outfall 002 when flow was present in a pipe discharging mine water from the Research Mine near the portal entrance. In the summer of 2005, OOSI constructed a mine drainage pipeline from the Research Mine to the top of the stormwater channel on the northern portion of the Lower Bench (see Technical Revision No. 6). This work was done to locate both outfalls in the upper part of Dry Gulch, so that the monitoring requirement at the downstream flume would apply to both outfalls. This work was verbally approved by CDPHE. Sampling was not conducted at Outfalls 001 and 002 during the reporting period because of no discharge of Outfall 002 at the end of pipe and no-flow conditions at the designated outfall point (flume). Quarterly NPDES Discharge Monitoring Reports were submitted to the CDPHE for Outfalls 001 and 002 during the reporting period. In February 2011, CDPHE, notified OOSI that a draft of a new individual CDPS permit (no. 000048816) for Logan Wash Mine was available for public comment. OOSI submitted comments to CDPHE on March 14, 2011. A new CDPS permit is expected to be issued in the near future. For more information regarding the Research Mine portal closure and management of the Research Mine drainage see Technical Revision (TR) No. 4 and TR No. 6 which present significant revisions to Exhibit E, the Reclamation Plan for Logan Wash Mine. 3.2 Mine-Water and Retort-Water Discharge Discharge measurements of clean (non-retort) mine-water discharge (Outfall 001) and retort- water discharge were conducted on a quarterly or more frequent basis when possible. These data were collected by OOSI to assess and evaluate mine closure effectiveness and to support operation and maintenance of the Evaporation Pond. Sampling of retort mine drainage water and mine water (Outfall 001) was conducted in June and November 2010 to evaluate retort water quality with time in support of eventual mine closure. The samples were collected from the retort drainage pipelines inside the Lower Bench Vault. 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. 3.3 Research Mine Manometer Monitoring The manometer installed in the Research Mine Vault is monitored and recorded on a weekly basis in the spring months of April and May, and at least quarterly at all other times. 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 according to the NPDES schedule. The manometer level recorded during 2010 observations was 0 inches, i.e. the mine was dry. 3.4 Evaporation Pond Leak Detection System In December 2009 and January 2010, inspections of the Evaporation Pond leak detection vault indicated that the vault was receiving water from the leak detection system as the vault progressively showed more water in the sump. Last year's report (March 2009 to March 2010) discusses the observations, actions, and monitoring activities associated with the leak detection system. In March 2010, the leak detection vault was no longer receiving water from the pond's leak detection pipes. Monitoring of the vault levels is conducted continuously using an installed Western Water & Land, Inc. 5