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<br />The Dtvision would propose two pet~rti[ting options suitable for usuring that the pos[ mining <br />land use of developed water resources will be established a['the site through the installation o! <br />slum wails. These options are described below. <br />Regulated Construction Option <br />The applicant may provide design drawings and specifica[iotts for the installation of the slum <br />wall along with a quality assurancefquality control plan. These documen[s would be binding <br />under the terrns of the permit, and the Division would require a statement that the plans and <br />specifications, once approved. could not be altered without consent by the Division. The <br />operator would be required to advise the Division of the schedule for construction of the slurry <br />wall so that inspections could be scheduled at appropriate times during installation. The operator <br />would be further required to provide a construction report de[ailing the installa[ion of the slurry <br />wall, describing any problems that occurred, and listing the results of testing that was conducted <br />under the approved quality assurance/quality control plan. A. cer[ifica[ion would be required [o <br />accompany the construction report with a statement from the quality assurance engineer [hat the <br />slurry wall was constructed in accordance with the approved plans and specifications. <br />With the level of revelatory control over the installation of the slurry wall described above, the <br />State would gain a high degree of assurance that the SEO required design standazd leakage <br />criterion is attainable. With this level of assurance, contingency bonding for repair or <br />replacement of 20 percent of the total lineaz feet of slurry wall is acceptable. The number of <br />lineaz feet of slurry wall and the slurry wall installation costs for the si[e aze discussed below. A <br />[able summarizing a typical specification and quality control plan is aaached. <br />Performance Bondin¢ Option <br />In [his option, the operators aze left to their own devices in the design, installation, and [esting of <br />the slurry wail, but would be required to demonstrate tha[ the slurry wall limits leakage into the <br />pit in accordance with the State Engineer's criteria. In this cttse, the Division would not have <br />regulatory control over construction of the slurry wall, and would bond for the cost to install a <br />complete replacement slurry wall. The performance bonding option considers the worst case <br />scenario where the slurry wall has been installed and the pit ltas been mined out, but it is <br />determined that the slurry wall leaks in excess of SEO requirement. Another consideration tha[ <br />enters into bonding for this worst case scenario is the potenti:il for leakage into the pit through <br />the bedrock pit floor. Unless the applicant can provide a seological evaluation of the proposed <br />pit floor bedrock tha[ demonstrates that leakage will not occur, the Division should bond for <br />sealing fractured or sandy bedrock that may be uncovered during mining and that may leak in <br />excess of SEO established criteria at this time. <br />Reservoir Filling <br />Past practices by the Division in permitting lined reservoirs included a requirement to provide <br />bond sufficient to purchase enough water from a reliable source to fill the reservoir one time. <br />numerous gravel pits have been reclaimed or are proposed to be reclaimed as lined storage <br />reservoirs since the passage of Senate Bill l20 in 1989. It has become clear that there is a great <br />d~ttand for lined storage in over appropriated basins. It is no longer a substantial concern to the <br />Division tha[ lined reservoirs will not be filled and put to their intended beneficial use along the <br />Fron[ Range. Tn the wors[ case, virtually any reservoir along the Front Range could be filled <br />