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<br /> <br />L~ <br />Lorrndra ! ~m.w~ lfe~e - Greuudinnrr reclvutal Rc.~ort <br />Raton/Vermejo Formation aquifer and water-bearing zone characteristics were described by <br />Howard (198?) from slug tests performed in the formations. iVlethodology employed in that <br />investigation involved the testing of wells screened across several zones within [he same formation <br />and the values derived are thought to be representative of the entire formation. Values determined <br />via laboratory core analyses indicate a mean horizontal hydraulic conductivity (k,) value of 9.38 <br />r 10'5 ft/day, and a mean vertical hydraulic conductivity (I:L) of 8.04 x ZO-5 ftfr/day. These values <br />are extremely low for sandstones (Heath, 1983). In addition, siltstone and shale were found <br />throughout [he site and are considered impermeable and semi-permeable layers that confine coals <br />and sandstones within the formation (Howard. 198?). Head differences in the aquifers would <br />seem to be the result of these confinins lavers. <br />In addition to laboratory analyses. Howard (1982) also performed field slug test; on wells installed <br />in the Raton/Vermejo Formations. These tests resulted in a ranee of K values from 1.07 x 10~ <br />ft/day [0 0.119 ft/day. The variance shows the complexity of the system of aquifers in the <br />Raton/Vermejo Formations. Within the data from Howard (1982) the well resulting in a K value <br />of 0.119 ft/day is anomalous. This well is the oNy well completed in oNv coal. and is not thought <br />[o be indicative of the entire formation. The mean value of the data presented by Howard indicates <br />a hydraulic conductivity of 0.0408 tt/day. The population standard deviation is 0.392. and sample <br />standard deviation (n-1) is 0.0419. A summary of [his data is presented on Table GW-10. <br />TABLE GW-10 <br />LORENCITO Cr1NYON MINE <br />AQUIFER TEST DATA <br />Well <br />No. <br />A uifer Aquifer <br />Thickness T <br />(e d/[[) S <br />(e d/fq K <br />ie d/frly K <br />(ft/dae) <br />1 Vermejo-Raton 125.0 4L1 0.0028 0.33 OA44 <br />2 Vermejo-Raton 238.5 212.0 0.1470 0.888 0.119 <br />3 Vermejo-Raton 165.7 4.I1 0.0028 0.025 0.0034 <br />4 Trinidad 50.0 5.46 0.0038 0.109 0.088 <br />6 Vermejo-Raton 198.6 31.613 0.3890 0.20 0.028 <br />7 Vermejo-Ramon 162.0 '_7.96 0.0194 0.17 0.023 <br />9 Vermejo-Raton 220.' 35.3 0.0020 0.16 0.021 <br />1l Raton 1875 0.143 0.00010 0.0008 0.000107 <br /> <br />l4 <br />Ratan ~, <br />~ . *. .« *. <br />l apd/fr = 0.134 ft/day <br />** -Test not complete <br />(From Howard, 1982) <br />Mean = 0.0408 <br />a~n = 0.0392 <br />axn' = 0.0419 <br />T = Transmissivity <br />S = S[orativity <br />li = Hydraulic Conductivitc <br />GrouuJ•.wicr ~~?`Dryember `l ~9~n 32 (revised 6/30/97) <br />