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Hayden, CO 81639 -0670 <br />From: Jones, Dennis D. <br />Sent: Wednesday, May 23, 2012 15:06 <br />To: 'Boulay, Mike' <br />Cc: 'Burgmaier, Susan'; Musick, Jason <br />Subject: well abandonments <br />Mike, <br />I am getting ready to abandon some wells. Per your reg's 4.07.3 <br />"(2) Exploration holes, drill holes or boreholes, wells, or other underground <br />openings completed in aquifers shall be sealed using cement or other <br />suitable sealant by placing the sealant in the hole from the bottom to <br />within 10 feet of the surface. Holes which have multiple aquifers or <br />bedrock aquifers not exhibiting artesian flow at the surface may be <br />sealed using a solid cement plug or other suitable media approved by <br />the Division extending 20 feet above and below the water bearing zone. <br />A surface plug shall be placed in accordance with 4.07.3(1) and the <br />hole shall be marked." <br />However, according to the State Engineers Office <br />16.2 Wells or Boreholes in Type II and Type III Aquifers - Wells completed into unconfined aquifers and unconsolidated aquifers <br />shall be plugged, sealed and abandoned by filling the well to the static water level with drill cuttings, clean sand or clean gravel, then <br />with clean native clays, cement or high solid bentonite grout to the ground surface. The uppermost five (5) feet of casing shall be <br />filled with grout or a permanent watertight cover shall be installed at the top of the casing. If casing is removed, the hole shall be <br />filled as described above to within five (5) feet of the ground surface. The top five (5) feet of the hole shall be filled with materials <br />less permeable than the surrounding soils that are adequately compacted to prevent settling. <br />So, basically, your reg's call for cement (or other sealant) in the bottom of the well, while the SOE calls for sand. Please give me a call <br />at your convience to discuss what we should do. <br />Thanks <br />Dennis Jones <br />Hydrologist - Seneca Coal Co. <br />970 - 276 -5209 <br />djones(@peabodyenergy.com <br />P ea h od yq ue. ENERG <br />37796 County Rd. 53 <br />PO Box 670 <br />Hayden, CO 81639 -0670 <br />