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-6- <br />61SC should submit corrected copies of those calculations. Contributing areas <br />numerical designations contained in the erosion calculations sheets in <br />Appendices XXI-6 and XXI-7 do not coincide with P1ap 2.05.3-C. Areas designated as <br />2 and 2A in USLE computations for the west side are not shovrn on Map 2.05.3-B. <br />IJSC must submit sediment calculations and maps on contributing area which agree <br />and delineate all areas designated as contributing to pond on a map. <br />9. Sediment ponds were designed on the basis of one year's sediment accural. <br />Three years sediment storage is generally required by the Division. This is due <br />to the tendency for a large portion of a year's sediment to be generated in a <br />single event. WSC should state how proposed maintenance and clean-out will <br />alleviate this concern. <br />10. Pond Dewatering: The applicant has failed to detail the proc~s.5.of pond <br />dewatering on all ponds except the 4lest h4ine Sediment Pond, which was detailed in .. ... <br />a separate section of the permit. The detailed drawing for the East Mine Pond <br />does not illustrate the dewatering device. 41SC should address dewatering mechanisms <br />for each pond. <br />11. Mine seepage: As per section 4.05.6(3)(a) all waters pumped from an under- <br />ground mine must be accounted for in sediment pond design. On page 2.05-25 mention ' <br />is given to annual production of water from the mine, 4JSC must show that pond <br />designs are adequate when estimated storage from any underground pumping is <br />considered, <br />12. USLE Cropping Factor: 4JSC should explain how the cropping factor of .15 <br />was selected for certain areas and explain how conditions will be maintained for <br />the permit t~rin to justify its use. <br />13. Sediment Control at Air Intake Shaft: Various maps and statements in the <br />text of the application are contradictory with respect to the proposed intake <br />shaft. It is the understanding of the Division that 41SC is proposing a disturbed <br />area of .14 acres adjacent to the highway and above the 100-year flood level. <br />Exhibit 2.05.3-D indicates a .14 acre disturbance-with sediment control being a <br />4" thick layer of gunite in a 50 ft. radius around the intake shaft. A letter <br />submitted to the Division dated January 28, 1981 requesting the small area <br />exemption stated that sediment control would be a gravel pad 1 foot thick and <br />50 feet in radius. The letter also states that the new site would alleviate the <br />need for an access road. Said access road is discussed on pages 4.03-1 through <br />4.03-5 and various other sections of the application and a total disturbed area <br />of .38 acres is discussed. The applicant should rectify these apparent discrep- <br />ancies and replace those sections of the application which are in error. <br />A topsoil stockpile is proposed adjacent to the intake shaft. Rather tran create <br />this additional disturbance, it is reconunended that any topsoil salvaged from the <br />site be transported to a pre-existing stockpile on the permit area. It should be <br />noted that topsoil quantity estimates were based on a .38 acre disturbance. <br />Revised calculations fora ,14 acre disturbance should be provided. <br />14. IJSC should verify that sediment ponds will be inspected during construction <br />and certified after construction by a qualified registered professional engineer <br />as required by 4,05.6(7). This certification must be provided to the Division <br />within one month of pond construction. <br />15. The applicant refers to a "U.S, Steel Pond", yet this pond is not shown on <br />eith~:r of Exfiihits 2.05.3-8 or 2.05.3-C, nor is it identified on any of the <br />