2020-07-09_REVISION - C1981028 ‎(12)‎

• Permit No: C1981028
• IBM Index Class Name: Revision
• Doc Date: 7/9/2020
• Type & Sequence: TR47
• Media Type: D
• Archive: No

Coors Energy Company: Keenesburg Mine
Technical Revision 47
Modification of Reclamation Success Standards
Using the average relative cover,published height at maturity, and calculated average annual
crude protein percentage, a relative crude protein percentage was calculated for each species in
each data set. If we assume that each reclamation area and reference area had the herbaceous
production calculated for the annual bond release standard, then we can compare the amount of
protein available to grazing animals from these different species compositions. Using this
approximation, all of the reclamation areas monitored in 2019 would have greater crude protein
content than the OSRA given a comparable total biomass production, and most would have
greater crude protein than would be expected from the seed mixture (Table 6). The same
calculations were made using the 2018 reclamation data(which was a much better precipitation
year)with similar results (Table 7).
Table 6: Calculated Relative 2019 Crude Protein Content for Various Species Compositions
OSRA 2019 Reclamation Data
Protein Seed Area Area Area Area Area Area Area
Component Mix 2003 2004 25 29 30 31 32 33 34
Cool Season 0.29 2.70 3.66 0.20 0.13 0.00 0.04 0.56 0.14 0.36
Warm Season 4.39 1.54 0.50 5.62 5.14 5.66 4.84 3.81 4.22 5.65
Total Protein 4.68 4.25 4.17 5.82 5.27 5.66 4.88 4.37 4.36 6.01
* Based on 2019 production standard (85.2 g/m2) and species composition
Table 7: Calculated Relative 2018 Crude Protein Content for Various Species Compositions
OSRA 2019 Reclamation Data
Protein Seed Area Area Area Area Area Area Area
Component Mix 2003 2004 25 29 30 31 32 33 34
Cool Season 0.52 4.81 6.48 0.32 0.20 0.00 0.03 0.75 10.18 0.49
Warm Season 7.79 2.73 0.91 9.59 9.36 9.98 8.47 7.12 0.00 10.33
Total Protein 8.31 7.53 7.40 9.91 9.56 9.98 8.49 7.86 10.18 10.82
* Based on 2018 production standard(151.2 g/m2) and species composition
6 SUMMARY
This technical revision modifies the vegetation composition standard for reclaimed rangelands at
Keenesburg Mine. The improved vegetation composition final bond release standard now
requires a minimum of four non-noxious,perennial grass species each contributing a minimum
of 3% and a maximum of 40%to relative cover. Seasonality in species composition is no longer
a requirement(i.e., either cool or warm season species in any combination may qualify to meet
this requirement). This revision documents that this standard is appropriate for the site, that it can
be met using the current seed mixture; and that it will provide a permanent, adequately diverse
vegetation community capable of supporting the post-mining land use of rangeland.
7 LITERATURE CITED
Brakie, M.2017.Plant Guide for Indiangrass (Sorghastrum nutans).USDA-Natural Resources
Conservation Service,East Texas Plant Materials Center.Nacogdoches, TX 75964.
Conner, A.B. 1940. The Chemical Composition of Forage Grasses of the East Texas Timber Country.
Texas Agricultural Experiment Station. College Station, Texas. Bulletin No. 582. March 1940.
8 July 2020