Laserfiche WebLink
Please let us know if you have comments. We plan to include a stipulation in the <br />PR-2 approval specifying submittal of the complete, comprehensive revegetation/soil <br />handling plan technical revision application by March 15, 2008. <br />Rule 2.05.3(5) Topsoil Salvage Information <br />61. The Division requested minor modification of the topsoil stockpile seedmix (to include <br />slender wheatgrass), and requested includsion of a general temporary stabilization <br />seedmix in the application, to be used on interim disturbances such as pond <br />embankments, road cuts and fills, temporary overburden stockpiles, etc. In response, <br />Colowyo provided an interim seedmix for use on topsoil stockpiles and pond <br />embankments, that is consistent with the soil stockpile seedmix in the current permit, <br />along with a commitment to add slender wheatgrass to the mix in the context of the <br />comprehensive revegetation plan revision addressed above in Item 60. This commitment <br />is included in amended Section 4.05.6 of the PR-2 application, and is acceptable. <br />For access road cut/fill stabilization, Colowyo included a separate seedmix within <br />amended Section 4.03.2 of the revision application, which is acceptable. <br />For the South Taylor temporary overburden stockpile, Colowyo developed a separate <br />stabilization seedmix, included in amended Section 2.05.3(1) of the PR-2 application. <br />This mix consists of annual oats, at 4 pounds PLS per acre and slender wheatgrass, at 2 <br />pounds PLS per acre. This is an extremely light seeding rate. Perennial seeding rates for <br />drill seeding are typically 30 to 40 PLS seeds per squaze foot, with rates doubled for <br />broadcast seeding. The perennial component of the proposed mix is only 7 seeds per <br />square foot. Typical rate for annual oats when seeded as a nurse crop is also significantly <br />higher than the rate proposed, typically in the 10 to 15 pound per acre range for drill <br />seeding. Such a low seeding rate as proposed may not result in satisfactory establishment <br />of a stand that will provide prompt and effective erosion control. Also, if areas of the pile <br />will remain inactive for more than 3-4 years; additional, longer lived perennial species <br />should be included in the mix, similaz to the mixes used for soil stockpiles and road <br />embankments. Finally, we note that in Section 2.05.3(6) of amended page R2-99, <br />Colowyo states that Temporary seeding may be employed during inactive times of <br />operations on the temporary [overburden) stockpile to reduce the erosion potential. We <br />believe it is important that the overburden stockpile be vegetatively stabilized if the <br />stockpile (or signifcant areas of the pile) will be inactive for more than one year. <br />Please amend the temporary overburden pile stabilization seedmix as appropriate, <br />and amend the related text in Section 2.05.3(6) to state that the temporary <br />overburden stockpile will be vegetatively stabilized if the stockpile (or significant <br />areas of the pile) will be inactive for more than one year. <br />7 <br />