1985-11-25_ENFORCEMENT - M1977378 (2)

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Mill Tailings Reveg----tion Project Page 3 bur.iied by the easily eroded tailings, and also prevents sandblasting of the seedling after germination. Another function of the snowfence is to increase winter snowpack on the sites for insulation and added moisture content. (2) Installation of a gravity feed irrigation system to increase moisture content on the site, and to reduce the albedo factor on the site since solarization is a problem. The second phase of the revegetation program, pioneer community estab- lishment, involves application of various cultural techniques for in- troduction of seed, fertilizer, mulch, and moisture to the site in order to achieve an initial plant cover or nurse crop. Then, the third phase involves introduction of secondary or successional community species such as forbs, shrubs, and trees. The secondary species are established through seeding, transplantation or natural invasion of indigenous species which is the method strived for, and facilitated by microclimate alterations accomplished during the first and second plases. Current Status The majority of the revegetation program on tailings pond No. 2 is in the first and second phases. A number of different cultural techniques and plant materials have been employed for the second phase and are delineated below by numbered plots. As evidenced by touring the differ- ent plots, some success has been achieved toward accomplishing the final goal , though persistency will only be known with time. While establishing seeded test plots on No. 2 in 1977 it became evident that the number and diversity of native plant materials, or even intro- duced materials, which had potential for establishment at this site were severely limited or not available. The Durango office of the Soil Conservation Service was then contacted to provide assistance in acquiring additional plant materials for testing. Through the evaluation planting program established at the site by SCS personnel , Wendell Hassell and Sam Stranathan, we have identified a number of materials demonstrating good potential for achieving revegetation objectives that might not have been tested otherwise. Climatology The elevation of the No. 2 tailings pond in 9,700 feet. The average daily high temperature for summer months June, July and August os 70°F, and the average daily low temperature for this period is 32°. The average annual high and low temperatures for the site are 70°F and -26°F respectively. An average 16 to 20 frost free days occur per year. The average annual precipitation is 12 to 18 inches, the majority of which occurs as snow- pack. Evaporation rates at the site differ for tailings tops and slopes, dependent on aspect. High evaporation recorded has been 0.25" for tail- ings pond slopes and 0.54" for pond tops. High gusty winds are a common occurrence in spring and fall , and are predominately southwesterly.