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<br />6.4.4 EXHIBIT D- Mining Plan <br />Overall the mining plan concept appears to be adequate, however, there are a few concerns that <br />were identified which will require some additional clarification and/or submittals as follows. <br />The primary concem involves water management and consumption. It is indicated that screening <br />and washing will be conducted with a portable plant as required. In addition, there will be water <br />consumed to conduct dust control activities. Under Exhibit G-Water Information, it appears that <br />you are planning on using surface water run-off collected and retained in a three-pond system to <br />supply these activities. How this water will be harvested and where the ponds will be located is <br />not clearly explained in either exhibit (D or G). Please provide additional detail on how this will <br />occur and update maps as necessary to illustrate this activity. <br />One of the concems that the Division has is whether or not this method will reliably supply the <br />projected annual needs. On page 22 it is stated that evaporative losses are expected to be <br />minimal, but there is no data to support this statement. In addition, it is stated that you do not <br />expect to have standing water in the pit except immediately following storm events before <br />percolation occurs. Therefore, given these statements, it appears that you do not intend to retain <br />surface water beyond those brief times after storm events, but this is apparently also going to <br />supply your water needs. Another point is that there can be extended periods of little to no <br />precipitation. What are your plans to satisfy your consumptive needs during these times? <br />Basically, the concept of harvesting surface precipitation run-off to satisfy your water needs <br />seems to be shaky at best. However, if you can demonstrate how this water will be captured and <br />stored to meet your needs, we will consider this proposal. Unfortunately, even if this can be <br />demonstrated, another area of concem will be whether or not this complies with state water law <br />since you will be intercepting and holding surface water run-off. Although our office does not <br />enforce state water laws, we cannot knowingly permit activities that may be in violation of those <br />laws and retaining surface water run-off for over 48 hours may require obtaining water rights <br />and/or augmentation plans for that stored water. <br />6.4.5 EXHIBIT E- Reclamation Plan <br />The reclamation plan is substantially adequate as submitted, however, there are a few areas of <br />concern that will need to be addressed. The first is the proposed maximum anticipated slope <br />gradient. On page 12 it is stated that the backfilled slopes will be approximately the same as the <br />pre-mining slopes of 2H:1 V and then later on in this exhibit (page 14) it states that final contours <br />are not expected [o exceed 3H:IV, especially on the valley floor. Based on the drawing E-1 it <br />certainly appears that the valley floor will be less than 3H:1 V and in fact is nearly level to very <br />gently sloping. The backfilled highwall in this drawing appeazs to be approximately 3H:1 V. <br />Based on DMG observations, any slope steeper than 3H:1 V is very prone to excessive erosion. <br />In fact 3H:1 V slopes often exhibit excessive erosion if surface water run-off is not properly <br />managed above theses slopes. Therefore, the application should be amended to clearly state that <br />reclaimed slopes will not exceed a slope gradient of 3H:1 V. <br />