INSPEC26288 - Laserfiche WebLink

Home Browse Search

Memo to Christine Johnston MCC 3rd Quarter 1995 Compaction Reporting page 2 the pertinent portions of the pile to determine whether adequate compaction has actually been achieved. If the error is determined to be graphical, the solution is much simpler. In that case Mountain Coal should provide the Division a copy of the original proctor test data sheet and a corrected curve. I recommend in any case that the Division require that all future proctor test summaries include the proctor test data summary. This information would allow the Division to resolve any possible graphical reporting problems expeditiously. The proctor test summary report, included in the third quarter lower refuse pile report, has one additional shortcoming. It reports that method D was used to complete the test and bears the note "Rock Correction". However, there is no notation of the amount of material substituted in completing the rock correction. In my memorandum of August 31, 1995, I included a recommendation addressing this concern. I recommended that all proctor test reports contain size gradation information for the 1/4" minus, 1/4" to 3/4", 3/4" - 3", and the 3" plus fractions of the samples analyzed. This limited size gradation characterizes the oversize constituency of the sample being analyzed. Based upon the intention for this sample to represent the overall waste, it therefore simplistically characterizes the waste. Field Density Testing Procedure Comments In my memorandum of August 31, 1995, I also included a recommendation intended to provide validation of each radioactive probe field density determination performed. I recommended that the technician excavate the detection sphere surrounding the probe following the completion of each density determination performed in order to determine the apparent proportion of coarse rock within the measured zone. Manufacturer's recommendations for the specific apparatus being used should be provided and adhered with. If the estimated proportion of coarse rock exceeds the proportion determined in performing the proctor analysis (portion of the sample replaced as rock correction), that fact should be noted on the report and the test should be repeated at a nearby location. Characterization of the Lower Refuse Pile In preparing this memorandum I completed a telephone conversation with Kathy Welt of Mountain Coal Company. Ms. Welt indicated that MCC recognizes the compaction determination difficulties inherent to coarse grained materials. In fact, Kathy inquired as to the procedure for demonstrating that the refuse is "durable rock", in accordance with Rule 4.09.4. Frankly, I do not believe our regulations or the OSMRE's ever anticipated a coal mine waste with