Laserfiche WebLink
ENVIRONMENT, INC. <br />NOVEMBER 14, 2014 <br />PAGE 5 <br />and filled around or placed on a flat place and filled around. While we take no action to <br />reach a specific compaction rate, the way the material is placed tends to compact the filled <br />area so settling is not a problem and the area once filled will be adequate for the end uses <br />we propose. In most cases the little settling that does occur can by corrected by grading the <br />surface within 3 year of final filling. <br />Albert Frei & Sons has not experienced any subsidence problems their other facilities that <br />are using this type of inert fill material and we do not expect any at this one. If voids are left <br />they usually occur under large pieces of rubble that block the finer material from infiltrating <br />the hollow areas thus preventing settlement. While the material is denser then the gravel <br />now there, it will still allow ground water to pass thru due to the interaction of the larger <br />chunks of material interspersed through the fill area. <br />This rubble will be covered by a 3 foot cover of finer material that is salvaged during filling. <br />The 3 foot cover will have no special characteristics except it will consist of smaller pieces of <br />the broken concrete, asphalt and dirt received during normal fill operations. If Option 1 (See <br />Figure E -1 & E -2) is used and the site is to be revegetated then, a final topsoil cover, <br />averaging 8 inches will be placed over the site to provide a seedbed. If Option 2 (See Figure <br />E -3) is used then 6 inches of gravel will be placed on the Industrial /Commercial areas until <br />they are developed. This will mean that the total cap depth will be a minimum of 3.5 feet <br />deep. <br />6.4.6 EXHIBIT F - Reclamation Plan Map <br />16) The final grading depicted on the reclamation plan map shows a slope ,steeper than 3H:1 V <br />between phase 1 and phase 2. Please re- submit the reclamation plan map depicting the final <br />topography with slopes 3H:1 V as described in the reclamation plan. <br />I have measured the slopes on the map and the western slope of Phase 2 is sloped 3:1. The <br />contours are 5 foot contours the top elevation is 5100, the base of the'slope elevation is <br />5075 so the height change is 25 feet. The horizontal distance is 75 feet (distance over <br />height is = 75/25 = 3:1. 1 have attached a revised Map Exhibit F - Reclamation Plan Map <br />where the contour lines have been changed to show the 5 foot contour lines as long dashed <br />lines, the 10 foot contours as solid lines and the 2 foot contours as short dashed lines. I also <br />labeled the slope 3:1 and revised the setback distance along the Thornton water complex. <br />17) Please provide two reclamation plan maps depicting the final topography and post - mining <br />land use for Option 1 and for Option 2. <br />Figure E -1 shows the area as if it were totally backfilled and seeded but not yet developed as <br />commercial /industrial area. Figure E -2 is drawn as described in Option 1 but only partially <br />backfilled and seeded. Figure E -3 is Option 2 with only the mine perimeter and undisturbed <br />areas shown as revegetated and the commercial /industrial development envelopes left as <br />unseeded. <br />6.4.8 EXHIBIT H - Wildlife Information <br />18) Please demonstrate that there are no threatened or endangered species from either federal or <br />state lists, inhabiting the proposed affected land. DRMS believes there is potential for threatened <br />or endangered species to inhabit the prairie dog colony located on the proposed affected land. <br />DRMS recommends the applicant perform a wildlife survey. <br />