Laserfiche WebLink
<br />disturbed more than 35 years ago and was originally a series of mine benches left along the sloping <br />footwall contact. At this time, all that is left is a mass of loose and heavily weathered gypsum <br />"pods" that are unstable and in too dangerous condition to approach with excavation equipment. <br />Highwall workers bar and drill a series of 2" x up to 6' holes for blasting with explosives to dislodge <br />the gypsum rock left remaining. During the past season, good progress was made utilizing high <br />pressure water to dislodge much of the loose rock and fines from the contact. The quarry water <br />truck is used to transport 4000 gallon loads of water to top of the highwall and several hundred feet <br />of high pressure hose is used to get the water to the working area. The water system has greatly <br />increased the production of loose material removal and we are hoping that 1999 field work will <br />complete this highwall stabilization task. <br />During the first quarter of 1999, the main mining benches of primarily gypstun rock were removed <br />along the 6850 level of the Senatore Hill Area and the 6935 level of Gold Hill. These vertical <br />highwalls up to 60 feet tall were drilled, shot, and worked with dozer and excavator to result in a <br />1:1 rock talus slope. The oversize gypsum boulders were worked to the toe(bottom) of the slope so <br />that the Large boulders will not someday become a safety concern. These areas are basically gypsum <br />rock talus slopes and are not scheduled for revegetation. Early season revegetation work includes <br />broadcast seeding of native grass mix (mix list attached) and straw mulch application at 4000#/acre. <br />500 pounds of grass seed mix and 700 pounds of shrub seed collected from the site during the 1998 <br />field season were broadcast over this year's and last year's disturbed areas. <br />A 50 head herd of cows was brought to the site during March and April, 1999, and fed grass hay <br />on the slopes along the hangingwall contact. The cows aze doing an excellent job of knocking down <br />the steeper rills along the slopes and depositing manure in the soil-less limestone and siltstone <br />materials were are attempting to revegetate. Eight acres of flat mining bench area located on <br />Senatore Hill and Gold Hill mining levels were covered with ]2" of planting medium, mostly <br />gypsum and limestone fines from stockpile areas in the South end of the site, seeded and mulched. <br />The cow herd was then fed hay in the areas to promote seed bed preparation via animal use. The <br />cow herd has been very effective in reducing the domination of Rabbitbrush species over grasses <br />in established areas by feeding hay in these areas. The animal impact has knocked back the <br />overbearing size and shading characteristics of the Rabbitbrush species and hopefully will promote <br />grass growth and overall plant diversity. It appears that animal browse impacts on the native grasses <br />growing on established areas is considerably different for bovine than deer browse. An early season <br />removal of old, stagnant growth should help to rejuvenate the grasses and promote increased vigor <br />to the established species site-wide. <br />A request has made to G-P Gypsum Corporation's legal office to forward a updated rider for the <br />surety bond carried by G-P for the Coaldale site directly to the Division. This update should be <br />forthcoming within the next few days. Should the Division have any questions regarding this report <br />or the surety bond status, please do not hesitate to contact me. <br />V ryV T~s <br />S <br />Kenneth S. Klco, Consulting Geologist <br />