Laserfiche WebLink
the special conditions required by Section 3.03.1(3)(e) For a Phase II release which involves <br />industrial, commercial or residential pos[mining land uses. <br />Topsoil Replacement Thickness <br />The Division's Guideline Reeardinp Selected Coal ~Y/i~te Bond Release Issues, dated April l8, 199, <br />calls for verification of replaced topsoil thicknesses in a Phase II bond release evaluation. At Hayden <br />Gulch Mine, replaced thicknesses must mee[ the 2l-inch minimum thickness the Division approved <br />in the permittee's reclamation plan (see copy of letter in Exhibit 5 of bond release submittal from <br />Division to HGCC dated January 2 f, 1988). The reclamation plan specified that only the A horizon <br />needed to be stockpiled due to the substantial abundance and thickness of that horizon. One topsoil <br />stockpile (Stockpile "C" next to west side of county road) was not needed. As approved by the <br />Division, it was seeded in place and not distributed. HGCC's bond release submittal contains field <br />data on topsoil thicknesses collected by HGCC and the Division. These data were verified in the <br />field by the Division. <br />IV. OBSERVATIONS AND FINDINGS -PHASE II RELEASE <br />Topsoil Thickness <br />11~Ieasurement of replaced topsoil thickness. The Division verified topsoil thicknesses cr. the bond <br />release block using a power auger during the October 1987 inspection. Thickness was measured at <br />40 randomly selected locations within the disturbed area. The Division's topsoil data aze kep[ in a <br />file titled "Topsoil Depth" under the heading "Soils" in the files of the Lead Specialist. <br />Comparison of measured topsoil thickness to minimum topsoil requirement. Average topsoil <br />thickness at the 401ocations was at least 21.75 inches, using a 24-inch auger. <br />Division's finding of compliance on topsoil thickness. The Division finds that the minimum <br />average of 21.75 inches indicates HGCC has replaced the necessary 21-inch topsoil thickness on the <br />reclaimed block submitted for Phase II bond release. <br />ReveQetation Success <br />Collection of vegetation sample data. Exhibit 1 of the bond release submittal describes the <br />methodology that HGCC used for sampling vegetation in the undisturbed reference azeas and in the <br />bond release parcel. Exhibit l also contains the data collected. HGCC collected the data in 1996 <br />and 1997 utilizing a plan previously approved by the Division. The plan was designed to ensure <br />randomness of samples and a statistically adequate number of samples. Cover was estimated using <br />a point intercept method. Production data were collected from one-meter quadrats. Shrub density was <br />determined by coun[ing s[ems in a belt transect. The Division reviewed HGCC's methodology in the <br />field at the start of sampling during the regular monthly inspection on August 9, 1996. <br />Hayden Gulch Mine Page 6 May 25, 1999 <br />Phase II/III Bond Release <br />