The current version of this model is described on the Hanwag site as using a sole described as: "The new HANWAG CompoSole is the first fully bio-degradable outsole for alpine and trekking boots. It is made from B2EARTH rubber blend and decomposes completely in less than 1500 days." Do you know if that sole is used in the model you are selling? If so, does it self decompose or does something need to be done to it at the land fill? I am concerned because I plan to wear out the boots I now have before using these Hanwags and it may be well into the "1500 days" before I begin to wear them. I have already ordered two pair of these because they were described on your site as exactly what I want, but now I wonder about the sole.