2009-08-13_PERMIT FILE - C1981019A (3)

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unmulched areas. The Division's initial permit concerns were expressed in the following Stipulation No. 4 found on page 32 of the September 28, 1982 MLRD Findings Document. STIPULATION NOA If in the future, on-site inspection by the Division or information collected by Colowyo indicate that the suspension of the mulching requirement is detrimental to vegetation establishment or contributes to excessive erosion, mulching will be resumed." Colowyo has intensively monitored the revegetation every year since 1983 and has reported the data to the Division in its Annual Reports. The data collected, as well as our observations in the field, indicate that, as expected, no adverse conditions can be attributed to not mulching. Vegetation has established as expected and there is no evidence of erosion directly attributed to the lack of mulch. The techniques currently utilized by Colowyo to control erosion on these unmulched slopes will continue to be implemented. It is generally recognized that it is the broken surface, contour furrows and drainage benches that contribute to erosion control rather than mulch. It is generally accepted by the local mines in the region that early mulching was completed because of a regulatory requirement rather than any ecological benefit towards successful reclamation. Colowyo recognizes that initial vegetation establishment will continually be monitored through the "monitoring plan" and field inspection by both the Division and Colowyo personnel will continue. If it appears that the suspension of the mulching requirement is detrimental to vegetation establishment or contributes to excessive erosion, mulching will be resumed. Similarly, if site-specific circumstances are encountered where mulching would be a useful metric, it will be reinstated for such circumstances. An example of such a circumstance might be steep slope revegetation in native drainages above sediment traps where vegetation was removed, but otherwise the surface was undisturbed. Given the more extensive south-facing aspects of the South Taylor area and the lack of aggressive non-native grasses in the seed mix, Colowyo is in agreement with CDRMS that the potential for erosion is increased in these areas and additional attention is warranted. Colowyo's continued preference is to utilize all mechanical measures (e.g., chisel plowing, dozer ripping, or discing on the contour, contour furrowing, etc.) before reinstating a mulching program. If a mulching program is proven to be warranted in the future, there is adequate research and precendence in the literature to suggest the most appropriate procedure to be utilized at Colowyo. The most practical and effective combination of soil stabilization measures will be implemented in the timeframe between final regrading activities and the completion of topsoil replacement. Should initial soil stabilization efforts prove to be ineffective, additional mechanical treatments, usually in the form of additional contour furrows will be added to eliminate excessive and progressive formation of rills and loss of the topsoil resource onto spoil areas. Irrigation No irrigation is planned for areas to be seeded or mulched. 2.05-61 Revision Date: 3/14/08 Revision No.: TR-72