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© MONTGOMERY YYATSON <br />Mining Group <br />l J <br />SENECA COAL COMPANY <br />MOISTURE-DENSITY TESTING FOR SENECA COAL COMPANY <br />POND 16 <br />Seneca Coal Company constructed Pond 1G during August and September 2000. Montgomery <br />Watson Mining Group was retained to conduct density testing during the construction efforts. The <br />following is a chronology of testing events and results of the testing conducted as the pond <br />embankment was constructed. <br />1G-Aug-00: T'wo samples of fill material were collected For particle sue and A[terberg Limit analysis <br />to verify the design parameters assumed durirtg the engineering of the pond embankment. Only one <br />sample was tested because both samples were similar based on visual classification. T}tese analyses <br />aze Included in Attachment A, Fie/d and l~bomlory Dala. The results of these analyses conducted on <br />the sample indicate the fill material placed has the index properties shown in Table 1, Summary of <br />Laboratory Turing. <br />• <br />TABLE 1 <br />SUMMARY OF LABORATORY TESTING <br /> Pond 1G Fill Sam le Proctor Test Sam le <br />Li uid Limit 37% 27% <br />Plastici Index 22% 15% <br />-#200 Sieve 83.0°,'° SG.O% <br />Proctor ASTM DG98 No Test 110.5 cE <br />These results closely match the physical chazacteristics of the proctor test sample taken at the site <br />during the ]999 pond construction season. Therefore, a conservative proctor value of 1 ]L0 pcf was <br />used far all in-situ density testing at Pond 1G during construction. <br />16-Aug-00 to 18-Sept-00: Twenty one (21) nuclear moisture/density tests was taken during the <br />construction of the Pond 16 embankment. Tests were taken at random locations as the fill was <br />placed Erom die base of the embankment up to the spillway crest elevation. The required percent <br />compaction for Fill placed was 95% of the soils maximum dry density detertttined by the Standard <br />Proctor method (ASTM DG98). All test results indicated that fill placed met or exceeded 95% <br />compaction with the exception of foot (4) tests. Tluee tests had results of 94.9% and one test was <br />94.8% for compaction. These test areas were recompacted but were not tested. Since these test <br />results are so close to 95%, the difference is inconsequential to the performance of the embankment. <br />Density test information is presented in Table 2, DenJity Test Summary. <br />u <br />R0. Boc 774016 <br />1475 Pine Grove Road <br />Steamhoat SRrings, Colorado <br />60477 <br />Te ~. 970 879 6160 <br />Fax 970 879 9048 <br />Serving the World's En v~r°nmental Needs <br />