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Page 6 of 11 <br />Mr. Jared Ebert <br />January 20, 2010 <br />21. On page 8 of the Groundwater Modeling and Mitigation Plan (Attachment G-1), it <br />states "Lafarge has no responsibility to provide mitigation for wells that are <br />constructed after the permit is approved." This is not correct, in accordance with rule <br />3.1.6 (1) the operator is required to minimize disturbances to the prevailing <br />hydrologic balance of the affected land and of the surrounding area and to the <br />quantity or quality of water in surface and groundwater systems both during and after <br />mining operations and during reclamation. Given this, if the mining and reclamation <br />operation impacts the ability of surrounding land owners to legally use groundwater, <br />Lafarge will be responsible for mitigating these disturbances. Please remove this <br />statement for the Groundwater Modeling and Mitigation Plan (Attachment G-1) and <br />submit a new copy. <br />This language was removed, attached is a revised copy. <br />22. It states on page 1 of the "Groundwater Modeling Evaluation - Potential Effects Due <br />to Mining" document that "...water levels outside the Parsons Mine area within <br />approximately 700 feet of the north permit boundary may increase 1 to 2 feet due to <br />post-mining reclamation activities. Simulated heads generally increased by 4 to 5 <br />feet within areas where mine excavation are to be filed with overburden spoils." An <br />increase in groundwater level such as this may negatively impact the surrounding <br />land. Please explain how Lafarge will maintain the prevailing hydrologic balance for <br />the areas surrounding the permit boundary after the site has been reclaimed. <br />The ultimate effects on groundwater levels beneath surrounding lands are not known <br />with certainty and will depend on both the hydraulic conductivity of backfill and <br />ground elevations in the reclaimed areas. Potential effects will be monitored and <br />addressed as part of the Monitoring and Mitigation Plan requirements. Lafarge <br />believes that given the most recent reclamation plans, significant increases in <br />groundwater levels are unlikely. Ifsuch adverse impacts did occur, they could likely <br />be mitigated by placing drains through the compacted backfill along the reclamation <br />slopes and channelizing flow to existing drainage swales andlor other hydrologic <br />features. <br />6.4.12 EXHIBIT L - Reclamation Costs <br />23. In order to review this section further and estimate a financial warranty, the Division <br />will need several pieces of information discussed in the sections above. This section <br />is still under review. <br />Please refer to above responses for answers to your requests for additional <br />information. <br />24. Since 60 acres of open groundwater will remain after the site is reclaimed, Lafarge <br />must obtain a court approved augmentation plan from the Office of the State <br />Engineer. The Division is required to set the financial warranty at a level which <br />reflects the actual current cost of fulfilling the conditions of the Reclamation Plan per <br />Rule 4.2.1(1). Therefore, without an augmentation plan in place the financial <br />warranty must be set at an amount which accounts for the exposed groundwater. The <br />Division has identified several options for determining the amount of the financial