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.. +~ SENEC.4 ~°~~~°m~~ Seneca Coal Company Jury 14, 2006 Mr. Mike Bonlay RECEIVED Division of Minerals and Geology 1313 Sherman Street, Room 215 ~U~ 2 4 206 Denver, CO 80203-2273 (303) 866-3567 Diuician oI Minerals i4 Geobgy RE: Seneca II-W Mine Permit C-82-057 W24 Series Well Abandonment Summary Dear Mr. 13oulay, In 2001, Seneca Coal Company (SCC) drilled five wells at the Seneca II-W South area. These wells were drilled on the same well pad, each one about ten feet away from the other. Installation of wells was required for ground water monitoring. These wells were required to determine the effects of surface ndning activities on the quality and quantity of water in ground water systems in the permit area and adjacent areas. At the time SCC had no othcr wells in this azea. A summary of these wells is provided here on Table 1. Sometime between April 21 to May 16, 2003, a landslide occurred above the wells. It occurred when the ground was saturated with spring snowtnelt. All five wells appeared to be bent below the ground surface, and three of the wellheads had sunk lower than the ground surface. On July 7, 2003, a weighted measuring line was lowered into the well casings. The interior of each well was pinched off at around twenty feet. See Table 1 for specific depths. At this time, SCC determined that the best way to repair the wells was to dig around them to the pinched off depths to assess the damage. Digging around these wells continued to the point where the excavation was to deep to enter safely. To proceed any further would involve benching back into the adjacent haul road and Sediment Pond 0164. Neither of these options was acceptable. Photos of the excavation were taken on August 7, and axe provided here. At this time, SCC decided to straighten the bent casings with a backhoe while the excavation was still open around them. The outer steel surface casing was straightened, however, the interior PVC well casing remained pinched off. 1-infonne8you and Dave bfcEihaney of-the Division of Water Resources (D\yIR) of our plat. to abandon the wells. On October 7, 2003, the excavation bottom was filled with french drain rock and an erosion blanket was placed on top of the rock, and then backfilled. Water discharging from the french drain flows into Pond 016, which is a NPDES discharge point. \~/i[h a drill rig on October 24, 2003, we attempted to force a tremmie pipe down the well casing, and fill the casing whth cement. However, we were unable to get the tremmie pipe past fifteen feet deep on any well. No cement vas placed in the wells. The third, and final, attempt to abandon the wells was made on August 15, 2005. This time, we attempted to pull the steel surface casing out of the ground with our largest backhoe. Oux plan was to fill the drill hole with cement after the steel casing was pulled. However, the steel casing could not be pulled out of the ground. Again, I notified you and Dave blcElhaney of our attempt. Seneca Coal Company • P.Q. Box 670 • Hayden, Colorado 81639 Telephone (970) 276-3707 • FAX (970) 276-3014