Abbreviated Application for Amendment of Certificate of Public Convenience and Necessity to Permit Reallocation of Certificated Storage Capacity Among Authorized Caverns of Leaf River Energy Center LLC under CP12-91.

LEAF RIVER CAPACITY REALLOCATION PROJECT RESOURCE REPORT NO. 6 - ADDENDUM GEOLOGICAL RESOURCES Resource Report No. 6 - Supplemental Geological Resources Leaf River Capacity Reallocation Project March 2012 Leaf River Energy Center LLC March 2012 LEAF RIVER CAPACITY REALLOCATION PROJECT RESOURCE REPORT NO. 6 - ADDENDUM GEOLOGICAL RESOURCES Figure 6.1-1 Generalized Geologic Map of Mississippi Leaf River Energy Center LLC 6-3 March 2012 LEAF RIVER CAPACITY REALLOCATION PROJECT RESOURCE REPORT NO. 6 - ADDENDUM GEOLOGICAL RESOURCES 6.1.1 Subsurface Geologic Setting 6.1.1.1 Methods A suite of geologic maps and cross-sections was constructed to characterize the geology of the New Home Salt Dome and adjacent strata. The scope of work included: Defining and updating the top of caprock/top of salt maps (Figures 6.1-2 and 6.1-3 respectively) in greater detail than was provided by the published map in Thieling and Moody (1997) through the integration of six lines of commercially available seismic data, two VSP (Vertical Seismic Profile) surveys and well data collected from project related drilling activities to date. Providing appropriate subsurface structure maps that characterize the flanks of the dome and the proposed brine disposal area. Integrating the above information into geologic cross-sections. Review of a database consisting of 20 geophysical logs from wells in the area including six that were on the New Home Salt Dome or its flanks. This well control was integrated with six seismic lines that crossed the dome and extended for several miles in each direction and two VSP surveys and data collected from project related drilling activities. Mapping for the details associated with the dome was done at a scale of one inch equals 500 feet. 6.1.1.2 Caprock/Salt Map Top of caprock and top of salt maps (Figures 6.1-2 and 6.1-3 respectively) were constructed from the available geological information, including seismic lines and surrounding well data. Several of the wells on top of the New Home Salt Dome penetrated salt and the values mapped were the depth of the first penetration of either caprock or salt. The information on caprock and/or salt penetrations from Thieling and Moody (1997) was heavily relied upon and was checked against the actual geophysical logs where these were available. The total depths of wells on the flanks of the New Home Salt Dome that did not penetrate salt were used as indirect control in the mapping. The resulting data were integrated into the seismic lines and VSP surveys that provide additional information as to the geometry of the salt diapir and ...