Laserfiche WebLink
where x is the cumulative value of precipitation from September to July of the following year, and y . <br />is the resultant vegetation cover." This cover standard is in agreement with Rule 4.15.8. <br />The Keenesburg Mine permit had previously utilized comparison of an approved reference area <br />(Rule 4.15.7 (3)), known as the Osgood reference area, for revegetation success of the reclaimed <br />areas. Comparison to the Osgood reference area was not ideal due to a successional change of the <br />species composition in the reference area to a community heavily dominated by sand sagebrush and <br />a reduction of forage grasses and forb species over the years. A change in surface ownership of the <br />property upon which the reference area was located caused concerns regarding management of the <br />reference area. The permittee proposed revegetation success standards for vegetative cover and <br />herbaceous productivity based on a formula derived from historic data collected on the Osgood <br />reference area and a correlation to precipitation records (TR37, approved June 15, 2006). <br />Cover <br />Vegetative cover data was collected in August 2007 and in September 2008 in accordance with the <br />methods described on permit page 116, and reported in the 2007 and 2008 Annual Reclamation <br />Reports. Precipitation is measured by CEC at the weather station located near the mine office. <br />Precipitation measured between September 2006 and July 2007 totaled 15.00 inches. Calculation of <br />the required vegetative cover standard for 2007 using 15.00 inches of precipitation resulted in the <br />reclamation success cover value of 36.45%. Ninety percent of this calculated value is 32.81 %. <br />Precipitation from September 2007 through July 2008 measured only 7.95 inches. Portions of <br />Colorado, including the Keenesburg area, experienced an unusually dry precipitation year in 2008. <br />Early parts of the growing season were very dry, with precipitation occurring at the latter portions of <br />the growing season when many plants were at the end of the growth cycle. The vegetative cover <br />success standard for 2008 was calculated to be 23.13% total vegetative cover. Ninety percent of the <br />2008 cover value is 20.82%. <br />The permittee sampled the seventeen parcels as two bond release blocks (BRB) based upon date of <br />seeding. One block was comprised of parcels seeded between 1985, 1986, and 1987 (reclamation <br />areas 4, 11, 12, 13, 17, 20 and 22) [1985/1986/1987 BRB]. The second block was comprised of <br />parcels seeded between 1995 and 1997 (reclamation areas 1, 3, 8, 14, 18, 21, 24, 26, 27, and 28) <br />[1995/1997 BRB]. The result of vegetative cover sampling for the 1985/1986/1987 BRB in 2007 <br />was a cover value of 60.80%. The 1985/1986/1987 BRB was sampled to adequacy in 2007, and the <br />measured cover exceeded the calculated vegetative cover standard for 2007 of 36.45%. The <br />1995/1997 BRB was sampled to adequacy in 2007, and the resulting cover was 61.40%. The <br />1995/1997 BRB exceeded the vegetative cover standard for 2007 of 36.45%. <br />Vegetative cover sampled on the 1985/1986/1987 BRB for 2008 was 63.20%. Vegetative cover <br />measured on the 1995/1997 BRB was 59.2% in 2008. Both of these blocks were sampled to <br />statistical adequacy and both bond release blocks exceeded the vegetative cover standard for 2008 <br />of 23.13%. <br />C1981-028, SL4 6 10/19/2009