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Mr. Robert Hagen - 2 - September 9, 1985 <br /> In regard to violation No. 2 of TDN 85-2-244-9, it was stated in your <br /> correspondence of August 29, 1985 that visual inspection of the surface area <br /> (at the rock tunnel waste ponds) indicates that material greater than six (6) <br /> inches was placed in the embankments. The Division would like to emphasize <br /> that in an embankment of this width (approximately 15 feet wide at the crest <br /> and 50 feet wide at the base) the material present at the surface is not a <br /> good indicator of the material within the embankment. As material is placed <br /> and worked in each two foot thick lift, the large material is winnowed from <br /> the center and collects on the outer edge of the worked lift. Also, as stated <br /> in the initial response to this TDN, testing was conducted as the embankment <br /> was constructed and the dam was certified as being built and compacted <br /> according to design. <br /> An inspector from the Division was present when the embankments in question <br /> were excavated to repair the principal spillway culverts. Photographic slides <br /> taken at this time and observations of the CMLRD inspector show no significant <br /> variations from the size gradation specifications. While excavating, the <br /> operator again conducted nuclear density testing and results were all <br /> acceptable. Due to the predominance of fine matrix material present in the <br /> fill, the nuclear density testing should be valid. <br /> The culverts exhibited piping along their base. The material around the <br /> culvert was replaced with compaction testing conducted throughout the <br /> operation. New, more extensive anti-seep collars were constructed by pouring <br /> concrete cut off walls around the culverts. <br /> The Division finds no evidence of a violation in the testing or material <br /> within the embankment. <br /> The letter accompanying TDN 85-2-244-12 references the original TDN as <br /> 85-2-244-6. Our records show this TDN to be 85-2-244-9. <br /> The Division will be pleased to supply any additional clarifications. <br /> Sincerely, <br /> d a <br /> Supervisor, Coal Program <br /> FRB/ljc <br /> 3232F <br />