2010-02-25_REPORT - C1981028 (6)

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(2000 Reclamation Areas) were quantitatively sampled this year for the first sampling of a two year sampling regimen prior to requesting final bond release on those areas in 2011. The • results of those vegetation investigations are contained in separate reports. The Keenesburg Mine 1985, 1986, and 1987 reclamation areas were monitored between 1994 and 1998, and subsequently released from Phase II liability in 1998 and Phase III liability in 2009 by CDRMS. The 1995 and 1997 reclamation areas at the mine were monitored between 1998 and 2004, and after successfully meeting revegetation success standards, were released from Phase II liability in 2006 and Phase III (final) liability in 2010 by CDRMS. 2.2 FIELD SAMPLING 2.2.1 Timing Field investigation for the 2002 and 2006 reclamation areas was undertaken during the period August 5-6, 2009. This time period coincided with anthesis and maximum development of the majority of plant species found in the reclaimed areas at the mine site and adjacent native areas. Total annual precipitation at the mine in calendar year 2009 to date was above normal. Cumulative precipitation between September 2008 and July 2009 (growing season precipitation) was 23.5 percent above the sixteen year mine average. While precipitation in the autumn and early winter of 2008 was near average, April, June, and July 2009 precipitation levels far exceeded average, providing significant growing season moisture for the revegetated areas. • 2.2.2 Vegetation Cover Vegetation cover was estimated by the use of the point-intercept method. An ocular point frame (ESCO Associates) was used to minimize instrument error and maximize precision and observer accuracy. Cover transects were 25 meters in length, with two sample data points collected at 1.0 meter intervals along the transect on opposite sides of the transect centerline, 1.5m apart. Transect direction was established randomly through the use of computer generated random directions (0-360°). In no event were transects allowed to extend within ten feet of reference or revegetated area boundaries to minimize impacts from "edge effect." For statistical purposes, each cover transect (comprising 50 data points) served as a sample unit. Data points recorded the first vertical "hit" on vegetation (above or below the instrument), soil (bare ground), rock, litter, or cryptogamic crust. Subsequent "hits" on vegetation (prior to interception of the ground) were also recorded. Cover data were recorded and reported by individual plant species. The first interception was used to calculate total vegetation cover values. Additional interceptions were used to calculate relative cover of individual plant species and lifeforms. The quantitative cover data also provided the basis for calculation of species composition and relative importance. Coors Energy Company Keenesburg Mine Page 7 2009 Revegetation Monitoring Report