2008-11-19_INSPECTION - M1976020

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(Page 2) MINE ID # OR PROSPECTING ID # M-1976-020 INSPECTION DATE 10/29/08 OBSERVATIONS INSPECTOR'S INITIALS WHE This inspection occurred as part of the Division's monitoring plan for permitted operations. The Thomas Pit is approved for extraction of alluvial materials from a side channel along the west bank of the Animas River and from a pit area located in the 100-year flood plain adjacent to the west bank. The permit is approved for 34.81 acres affected land. The Division holds $26,295 financial warranty. Permit status is active. The current Operator, Four Corners Materials, does not currently have an approved 404 permit from the US Army Corps of Engineers (COE) to conduct in-stream mining activities. Therefore, in-stream mining activities are dormant. However, the Operator has attained COE approval to install stream channel stabilization structures and to remove man-made obstructions to the floodway located above the high water elevation. Four photos accompany this report. As shown in the photos, significant quantities of sediment are deposited seasonally in the reach of riverwithin which the permit area is located. Portions of the two V-weir structures installed by the Operator in 2007 in accordance with the COE permit have been buried in sediment and/or raveled by high flows. In 2007 the Operator also removed the man-made flood dike previously located between the main channel of the Animas River and the side channel mining area. Sediment deposition in the side channel has occurred sufficient to return portions of the river, even during low flow season, back to the main channel of the Animas River. Division records indicate that prior to the permit, before 1976, the side channel had been excavated by a floating dredge. The dredged channel was approximately 900 feet long, 200 feet wide and potentially 30 feet deep. The dredged channel formed a basin adjacent to and deeper than the river channel and presumably captured a significant portion of the river flow. The original mine plan allowed the operator to excavate sediment from the pre-permit dredge basin deposited seasonally by the Animas River. Such mining activities occurred from 1976 to 1996. In 1996 a previous operator did not renew the COE permit and in-stream excavation activity ceased. Division records indicate that excavation of sediment from the side channel dredge basin has not occurred since 1996 and the basin has only recently refilled sufficient to return the majority of the Animas River to its main channel. Since 1996 the previous and current operators have maintained an active status by conducting mining activities in the flood plain areas adjacent to the west bank. Reclamation backfill and grading of the excavated pond, located at the south end of the permit area and approved through AM-01, appeared to have been completed in accordance with the reclamation plan. The pond was receiving water from irrigation ditches. The rock-lined open channel emergency spillway appeared intact and stable; no evidence of discharge from the pond was observed. The jetty structure and double row of concrete blocks installed along the west bank and adjacent to the pond appeared stable. However, establishment of the 360 Willow shrubs and 75 Cottonwood trees for the embankment, as approved through AM-01, has not yet occurred. Please be aware that annual reports always require a map of current site conditions, regardless of whether any disturbance has occurred during the report year. No problems or possible violations were observed. Response to this inspection report should be directed to the Division's office in Durango at 691 County Road 233, Suite A-2, Durango, CO 81301, to the attention of Wally Erickson, phone (970) 247-5469. I & E Contact Address cc: Steve Shuey, DRMS ? CE NAME Peter Kearl ? BL OPERATOR Four Corners Materials ? FS STREET P.O. Box 1969 ? HW CITY/STATE/ZIP Bavfield, CO 81122 ? HMWMD (CH) ? SE ? WQCD (CH) ? OTHER