Laserfiche WebLink
Sediment Control <br />During construction, deadheading, and reclamation of the deadhead routes, <br />Seneca will utilize road berms, silt fence, and hay bales to minimize <br />sediment rounoff. These same techniques were used during construction of <br />Haul Roads "A" and "B". As previously mentioned, should a culvert be <br />required, the sizing will be based on the information in Attachment 13-9, <br />Light-use Roads Generic Culvert Design. Because of the disturbance in the <br />drainage channel (located on Maneotis' property) underneath the PSCO/ WAPA <br />powerlines, a temporary diversion ditch and postmine drainage channel <br />needed to be designed. Addendums 13-10A and 13-lOB contain the design <br />information for both channels, respectively. <br />SEDCAD+ was used to design the temporary diversion ditch using the <br />erodible/riprap channel options. SEDCAD4, an updated version of SEDCAD+, <br />was used to design the reconstructed postmine channel. The contributing <br />watershed area is 1,145 acres. A very conservative curve number value of <br />80 was input to calculate the runoff volume and peak discharge for the <br />temporary diversion ditch design. The reconstructed postmine channel <br />design utilized an area-weighed curve number value that was developed for <br />existing landscape conditions. Soil mapping information and vegetation <br />type and cover condition were based on Natural Resource Conservation <br />Service (MRCS) soil survey data (NRCS, unpublished). <br />The temporary diversion was a triangular ditch with 2:1 sideslopes, a one <br />percent bed slope, and at a minimum, 1.5 feet deep. <br />Reclamation <br />As was stated earlier, all constructed roads will be reclaimed as soon as <br />the dragline passes and equipment can operate safely. All disturbance and <br />reclaimed acreages associated with the dragline move will be provided in <br />the 1996 Annual Reclamation Report. <br />All areas disturbed will be graded back to approximate original contour. <br />The areas where topsoil was windrowed out to the edges of the road will be <br />replaced in the same manner. Upon completion of topsoil replacement, <br />seeding will be accomplished on all disturbed acres, even those where <br />topsoil was not moved. Several tables in Tab 22 were revised to contain <br />the pertinent acreages related to this project. The two main seed mixes <br />which will be planted are Seed Mix 1B (shrub grassland) and Seed Mix 3 <br />(Alkaline lowlands). Seed Mix 3 will be planted in the drainage channel, <br />and all other areas will be done with Seed Mix 1B. The tables in Tab 22 <br />were revised to reflect a maximum disturbance of 65.0 acres, but in <br />reality, this will not be the case. <br />TR-36 13-10-5 Revised 08/07 <br />