Laserfiche WebLink
• Freshwater Pond No. 3 (reclaimed) <br />• Sedimentation Pond No. 4 <br />• Power Substations 1 and 2 <br />• Powerlines (most removed during reclamation) <br />• City of Florence Waterline (portions abandoned) <br />• Telephone Communications Lines (most removed during reclamation) <br />Structures associated with EFCI's mining and related activities, including office, <br />shop, warehouse, preparation plant, and loadout facilities, were not undermined, <br />and therefore, were not affected by subsidence. The configuration of potentially <br />affected structures within the area of concern is illustrated by the Mine Surface <br />Facilities Map, (Map 18). EFCI's subsidence inventory does not delineate any <br />renewable resource lands within potentially affected areas. <br />Probable and Worst Case Subsidence. Based on the subsidence report prepared <br />by RMG in 1983 for Dorchester, both the maximum expected probable and worst- <br />case subsidence ranges were predicted. RMG predicted probable maximum <br />vertical subsidence for combined advance and retreat mining to range from 1.46 <br />to 5.85 feet. These predictions apply to Southfield's overall mine plan within the <br />permit area. Where pillars are left (development extraction only), RMG predicted <br />worst-case vertical subsidence ranging from 2.60 to 4.36 feet. <br />The RMG subsidence predictions and subsidence control plan were used by EFCI <br />during the period of active mining and have proven to be accurate. Actual <br />subsidence monitoring data collected over the past eighteen years by both <br />Dorchester and EFCI indicate vertical subsidence ranging between 0.03 and 3.21 <br />feet (Florence Waterline Station I), well within the ranges predicted by RMG. <br />Actual subsidence data can be found on Table 1, High Reso/ution Grid Survey <br />Data, and in the Semi-Annual Subsidence Reports contained in Exhibit 23, <br />Subsidence Information. <br />Based on worst-case subsidence projections, the RMG report determined that <br />some material damage or diminution of reasonable foreseeable use could result. <br />Srrrce the poterrtral for damage existed, damage eva~uatrons avere compieted <br />under applicable provisions of Sections 2.05.6 (6) and 4.20. An evaluation of <br />material damage or diminution of reasonable foreseeable use for the Southfield <br />mine area was determined on a site-by-site or structure-by-structure basis. <br />TR-36 2.05.6-56 Revised -October 2003 <br />