2021-09-07_REVISION - M1973021 (4)

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Aggregate Industries, Morrison Quarry Amendment No.7 to Permit M-1973-021 FN Morrison,CO and 9.0, then covered with a layer of growth medium material. The growth medium material will be developed from a blend of any available topsoil stockpiled on site as well as material available from the excavation and breakdown of the fine-grained sedimentary overburden rock, supplemented as needed by imported topsoil, biosolids, or compost, then blended, scarified, seeded, and mulched. The topsoil materials will be transported using front-end wheel loaders or articulating haul trucks. This material will then be uniformly spread in 6-inch layers and mixed with conventional earthmoving equipment, such as bulldozer rippers or the teeth of an excavator bucket, into the top 12 inches of the subsoil. For reclamation of the mined and un-mined areas, it is anticipated that the soil conditioning area covers approximately 154.6 acres. For purposes of estimating costs (Exhibit L— Reclamation Costs), Aggregate Industries, Inc. estimates that up to 25% of the required topsoil sources will be collected and stockpiled on site, providing an assumed 26,055 cubic yards of topsoil. To provide 6 inches of topsoil cover for the remaining 75% of reclamation areas, Aggregate Industries, Inc. estimates importing 78,166 cubic yards of organic material to meet the requirements below. The costs of utilizing topsoil sources onsite versus imported soil growth medium have been broken out as separate lines in the estimated costs table in Exhibit L— Reclamation Costs. To reduce the dependency on imported topsoil, the operator will continue to evaluate amending site soils to develop suitable organic material prior to full reclamation of the site. Imported soil amendments will be from a local source of material to be generated during test plot development and reclamation. Caked or lumpy soil amendments will not be accepted. If selected as the preferred source, manure will be dry cow, horse, or sheep manure that has been stockpiled for a minimum of 1 year. Manure will not be so caked or lumpy that it cannot be spread uniformly. Compost manure will be stabilized through at least one heating cycle (120 to 140 degrees Fahrenheit), turned at least once, windrowed for at least 45 days, and stockpiled for a least 2 months. Biosolids or compost biosolids, containing municipal biosolids, will meet Colorado Department of Public Health and Environment (CDPHE) Water Quality Control Commission 5 Code of Colorado Regulations 1002-64 Biosolids Regulation No. 64, including permitting and regulatory approval procedures. Soil amendments will not contain pathogens or toxic materials harmful to human health or vegetation growth. Item 11.0 Revegetation It is anticipated that the revegetation area of the North, Central, and South/West Quarries covers approximately 154.6 acres. Seeding of the reclaimed areas assumes a native seed mix composed of the species and mixtures listed in Table E-2. This seed mix incorporates species that have performed well at the site to date. Assumed application rates of 48.0 Ibs of pure, live seed per acre have been doubled in Exhibit L—Reclamation Costs to account for broadcast seeding. Revegetation will be performed approximately on a yearly basis, preferably in late fall (November), for any area that has been backfilled, graded, and shaped. Seeding of a native grass seed mix will be performed by the hydroseeding method. This method allows for seeding on fairly steep slopes; provides complete coverage; and combines mulch, September 2021 1 36