Laserfiche WebLink
unusual results obtained. This examination should include the process of obtaining <br />the material properties and the proctor standard, as well as the compaction testing <br />itself. The Division requests that BRL examine the results of the compaction tests <br />and verify to the Division that the results are accurate and representative. <br />Depending on these findings, the Division may require BRL to retest for <br />compaction. <br />3. The Division is concerned that, if subsoil is being used to mir with overly wet coal <br />mine waste material, there might not be enough subsoil stockpiled at the coverfill <br />stockpile to use as cover over the gob pile when the pile is reclaimed. Please <br />comment. <br />BRL has not replied to this question. It is an important consideration since the <br />reclamation bond estimate would be inadequate if subsoil material would need to <br />be brought in from another source. Please provide a survey of the volume of the <br />subsoil stored at the coverfill stockpile. <br />4. The Division is concerned that no compaction tests have been performed to date at <br />the gob pile. It is the Division's opinion that compaction testing should be <br />performed at least quarterly, possibly on each two foot lift, and especially in the <br />very early stage of the gob pile's development. In that way, the geotechnical <br />engineer would be able to determine whether or not the gob pile construction was <br />proper, so that any remediation work, if needed, would not be costly and difficult. <br />Please comment on why no compaction testing at the gob pile has been done to <br />date, considering how much material has already been placed there. Also, please <br />comment on how the operator is confident that the compaction at the gob pile has <br />occurred according to design. <br />The Division's field inspection of February 24, 1998 showed that the height of the <br />gob pile at that time was about 20 feet. The compaction tests submitted to the <br />Division show that the first compaction test was performed on March 5, 1998. The <br />Division believes that the lack of compaction testing for this amount of initial toe <br />material is a matter of concern. Although the first quarter engineer's certification <br />does state that the gob pile was basically dry and that no signs of instability were <br />observed, the fact remains that visual inspection occurs over a short duration of <br />time and does not provide factual verification of the stability of the pile. The <br />Division believes that it is good engineering practice to confirm the compaction <br />efforts, especially for the initial toe material and especially when the material <br />