2012-04-30_HYDROLOGY - M1977208 (3)

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Summary: The CEMEX cement plant is located east of Lyons Colorado. The facility consists of a quarry for the mining of high calcium carbonate shale and the Fort Hays Limestone, both at the base of the Niobrara Formation, for the production of cement. Previously drilled water monitoring well CEM -005 became damaged at a depth of approximately 50 feet below ground surface (BGS) when the Schedule 40 Polyvinal Carbonate (PVC) pipe broke. Well CEM -005 is intended to sample water within the Carlile Shale, which directly underlies the Fort Hays Limestone in an effort to monitor the water that may migrate from the cement kiln dust disposal site (C -Pit) to groundwater. In an effort to reduce the likelihood of repeated well damage, the new well was constructed with Schedule 80 PVC pipe. The new well was designed to mirror the previous CEM -005 as closely as possible. Drilling Timeline: Drilling started on Wednesday March 28, 2012. Conditions on March 28, 2012 were partly cloudy and 70 °F with 5 -10 miles per hour (mph) winds from variable directions (predominantly southeast and south). On this date, the well was drilled from ground surface to a total depth of 400' BGS. Conditions on Thursday March 29, 2012 were partly cloudy and mid 70s °F with 5 -10 mph winds from predominantly southeast and south. On this date, the well casing was set to total depth, the sand filter pack was placed, and the bentonite grout seal was placed to a depth of 204 feet BGS. The grout was not placed to surface on this date because the grout set up too quickly in the tremie pipe, rendering the tremie pipe unusable. Conditions on Friday March 30, 2012 were partly cloudy and mid 70s °F with 5 -10 mph winds from the southeast and south. On this date, the well grout was placed to surface, the conductor casing was pulled and the well was bailed and developed. On Monday April 2, 2012 drillers returned to the site, reported that the well was not producing water (only a few gallons were in the bottom of the well, as indicated by a water level indicator). Subsequently they backfilled the cuttings sump, placed a converter on the top of the casing to convert the top to accept a J -plug designed for Schedule 40 PVC (no J -plug is made for Schedule 80), placed the protective metal casing on the well, constructed a concrete well pad and demobilized from the site. PWT was not on site on Monday April 2, 2012. CEMEX personnel verified the work conducted on April 2, 2012.. Lithologic Descriptions: The well lithology was similar from the first encounter with bedrock at (approximately) 36 feet to the first contact with bedded limestone at (approximately) 273 feet BGS. The Smoky Hill Shale is described as follows: Black (Munsell Color 5Y 2.5/1), carbonaceous, moderately hard, platy to blocky, fair to good fissility, petroliferous smell, silty and overall increasing in calcareous content with depth. Accessory minerals included: Chert: Brown (Munsell Color 10 YR 5/3), moderately hard. Limestone: White (Munsell Color Gley 1 8/), moderately hard, crystalline. Pyrite: Crystalline, hard. The Fort Hays Limestone is described as follows: Page2 of 4 P I ACIFIC WESTERN TECHNOLOGIES, LTD.