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M E M O R A N D U M <br />MONTGOMERY WATSON <br />Minirig Group <br />Date: 22-Mar-00 <br />To: Seneca Coal <br />From: Craig Burger and Tom Leidich <br />Subject: Haul Road H Construction Quality Assurance <br />The purpose of this memorandum is to present the results of quality assurance testing performed <br />during the construction of Haul Road H. The alignment and stationing of the haul road are shown on <br />Drawing 1. <br />Seneca Coal Company constructed Haul Road H in June and July of 1999. Montgomery Watson <br />Mining Group was retained to conduct density testing during the construction efforts. A <br />chronology of testing events and the results of the testing conducted as the haul road was <br />constructed follows. <br />• Samples were collected for proctor testing on June 21, 1999. Two samples were collected near <br />the location of culvert H-2 (samples H-1 and H-2) and two samples were collected midway <br />between culvert H-1 and H-2 (samples H-3 and H-4). The samples were submitted to Northwest <br />Colorado Consultants for analysis. The maximum dry densities of these samples ranged from <br />103 pcf to 111.4 pcf, and optimum moisture contents ranged from 13.7% to I5.5%. The results <br />for each sample are attached to this memo. <br />Moisture/density tests were conducted on June 29 and July 2, 1999. A modified proctor value of <br />1 I I.0 pcf was used for all density tests, and all tests were run for 1 minute at a depth of 12 <br />inches. Construction specifications for the road require all fill material to be compacted to 90% <br />of the modified proctor. A moisture content specification was not stipulated. The results from <br />these two days of testing are presented in Table 1, Results of Moisture/Density Testing at Haul <br />Road H. <br />Montgomery Watson personnel conducted density testing at the locations of culverts Hl, H2, and <br />H3 during backfilling and performed density testing on final subgrade from Stations 0+00 to <br />31+00. A summary of the field density testing results and their approximate locations are <br />presented in Table I. Seneca II-W Mine -Haul Road H Summazy of Testing. <br />6/29/99 -Four nuclear moisture/density tests were conducted using a Troxler Gauge. Two tests <br />were taken in the vicinity of culvert H I and two tests in the fill over culvert H2. All test results <br />• were within 90% of the maximum dry density value of I I I pcf. <br />J SYFZ,W,~.JJIneLnuAll (luulin Ruunm.. llrnn An, <br />