2010-12-17_REVISION - C1981019 (153)

Home Browse Search

Introduction 5 - estimation of permeabilities, and documentation of pre- mining water quality. • Characterization of the surface water flow regime, including: - review and update of previous stream and seep characterizations, - quantification and characterization of stream flows, and - documentation of pre- mining water quality. Work performed to meet the objectives of the Work Plan are as follows: • evaluated geologic borings conducted for coal resource and geotechnical studies; • installed and developed 13 bedrock and 5 valley fill monitoring wells for baseline water quality data and water level data; • installed 18 piezometers for water level data; • conducted 27 slug and single -well pumping tests in bedrock wells and cased piezometers; • conducted 5 slug tests in valley fill wells; C • measured water levels in wells and piezometers; • installed pilot dewatering well test cluster; • conducted a long -term pilot dewatering test; • conducted surface water and groundwater sampling; • conducted spring and seep survey, gaging and water sampling; • evaluated the permeability and mineralogy of the KM; • developed a hydrogeologic conceptual model; • developed and calibrated a 2D numerical pore pressure model to evaluate slope depressurization requirements; and • developed a pre - feasibility level dewatering /depressurization design. 1.5 Report organization Sections 2 through 5 of this report describe baseline conditions related to geology (Section 2), meteorology (Section 3), surface water hydrology and chemistry, including springs and seeps (Section 4), and groundwater hydrology /chemistry (Section 5). Sections 2 through 5 also contain detailed descriptions of the data collection programs. 2572 -R2 Colowyo Coal Company Water Management Consultants